WO2004074170A1 - Composite material, structural body and method of manufacturing the structural body, polycrystalline structural film, and method of manufacturing particulates - Google Patents

Composite material, structural body and method of manufacturing the structural body, polycrystalline structural film, and method of manufacturing particulates Download PDF

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Publication number
WO2004074170A1
WO2004074170A1 PCT/JP2003/001875 JP0301875W WO2004074170A1 WO 2004074170 A1 WO2004074170 A1 WO 2004074170A1 JP 0301875 W JP0301875 W JP 0301875W WO 2004074170 A1 WO2004074170 A1 WO 2004074170A1
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WO
WIPO (PCT)
Prior art keywords
fine particles
magnetic
layer
substrate
nanoparticles
Prior art date
Application number
PCT/JP2003/001875
Other languages
French (fr)
Japanese (ja)
Inventor
Nobutaka Ihara
Takuya Uzumaki
Atsushi Tanaka
Satoru Momose
Hiroyoshi Kodama
Original Assignee
Fujitsu Limited
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Fujitsu Limited filed Critical Fujitsu Limited
Priority to PCT/JP2003/001875 priority Critical patent/WO2004074170A1/en
Priority to JP2004568485A priority patent/JPWO2004074170A1/en
Publication of WO2004074170A1 publication Critical patent/WO2004074170A1/en
Priority to US11/091,734 priority patent/US20050196606A1/en

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Classifications

    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23CCOATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C30/00Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/62Record carriers characterised by the selection of the material
    • G11B5/73Base layers, i.e. all non-magnetic layers lying under a lowermost magnetic recording layer, e.g. including any non-magnetic layer in between a first magnetic recording layer and either an underlying substrate or a soft magnetic underlayer
    • G11B5/7368Non-polymeric layer under the lowermost magnetic recording layer
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/62Record carriers characterised by the selection of the material
    • G11B5/73Base layers, i.e. all non-magnetic layers lying under a lowermost magnetic recording layer, e.g. including any non-magnetic layer in between a first magnetic recording layer and either an underlying substrate or a soft magnetic underlayer
    • G11B5/7368Non-polymeric layer under the lowermost magnetic recording layer
    • G11B5/7377Physical structure of underlayer, e.g. texture
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/84Processes or apparatus specially adapted for manufacturing record carriers
    • G11B5/855Coating only part of a support with a magnetic layer
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01FMAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F10/00Thin magnetic films, e.g. of one-domain structure
    • H01F10/08Thin magnetic films, e.g. of one-domain structure characterised by magnetic layers
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01FMAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F41/00Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
    • H01F41/14Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for applying magnetic films to substrates
    • H01F41/16Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for applying magnetic films to substrates the magnetic material being applied in the form of particles, e.g. by serigraphy, to form thick magnetic films or precursors therefor

Definitions

  • the present invention relates to a composite material, a structure and a method for producing the same, a polycrystalline structure film and a method for producing fine particles
  • the present invention relates to a composite material, a structure and a method for producing the same, which can be used for a magnetic recording medium such as a hard disk (HD), a polycrystalline structure film, and a method for producing fine particles.
  • a magnetic recording medium such as a hard disk (HD), a polycrystalline structure film, and a method for producing fine particles.
  • nanoholes are widely known.
  • minute holes are formed, for example, on the surface of the alumina film on the substrate.
  • minute holes are regularly arranged at minute intervals.
  • the minute holes are filled with a magnetic material such as C0 or a Co-based alloy. Magnetic crystal grains are formed for each minute hole.
  • the recording density of magnetic information can be increased.
  • Magnetic recording media using iron platinum (FePt) nanoparticles have been proposed.
  • nanoparticles encapsulated in oleylamine oleate are prepared. These nanoparticles are stored in an organic solvent such as hexane. The nanoparticles are applied to a substrate of a magnetic recording medium together with an organic solvent. Thereafter, the nanoparticles are annealed. Nanoparticles crystallize based on this annealing treatment.
  • the process is performed, the fusion of nanoparticles is caused by the large thermal energy. As a result, the grains become enlarged.
  • a magnetic polycrystalline layer is widely used for the recording magnetic layer. If the crystal grain size is reduced in the magnetic polycrystalline layer, the recording density of magnetic information can be further increased.
  • a so-called seed layer that is, a fine crystal nucleus, is used to make such crystal grains fine. When the magnetic material is sputtered on the seed layer, fine crystal grains can grow from the crystal nuclei.
  • Sputtering is used to form the seed layer.
  • an ultrathin film of, for example, a metal material is formed based on the sputtering.
  • fine crystal nuclei can be formed in the ultrathin film.
  • the size and dispersion of crystal nuclei in such ultrathin films cannot be adequately controlled.
  • the size and distribution of crystal grains vary.
  • a method for producing nano metal particles based on the so-called polyol method is widely known.
  • This polyol method is widely used, for example, in producing cobalt particles.
  • Cobalt is reduced from salts such as cobalt acetate by the action of a reducing agent, diol.
  • diol a reducing agent
  • agglomeration of nanoparticles is easily caused.
  • nanoparticles of special metal alloys are manufactured, enlargement of the nanoparticles cannot be avoided.
  • Patent Document 1
  • the present invention has been made in view of the above circumstances, and an object of the present invention is to provide a composite material capable of relatively easily and uniformly filling a magnetic material in minute holes and a method for producing the same.
  • An object of the present invention is to provide a structure capable of forming finer crystal grains than ever, and a method for producing the same.
  • An object of the present invention is to provide a polycrystalline structure film capable of sufficiently controlling the size and dispersion of crystal nuclei.
  • An object of the present invention is to provide a method for producing fine and uniform fine particles relatively easily.
  • a composite material comprising: a base; and microparticles arranged in microholes formed in the surface of the base.
  • the microparticles can be reliably placed in the microholes. That is, the microparticles are completely contained in the microholes. Moreover, the position of the microhole can be controlled regularly. Based on these small holes, the small particles can be arranged regularly.
  • the microparticles are deposited in the microholes by being laminated on the surface of the substrate.
  • a confining coating layer may be formed. According to such a coating layer, the fine particles are completely contained in the fine holes. There are no microparticles on the surface of the substrate.
  • one of the substrate and the fine particles may be made of a magnetic material, and the other may be made of a non-magnetic material.
  • one of the substrate and the fine particles may be made of a conductor, and the other may be made of an insulator.
  • the fine particles may be composed of a metal element.
  • the fine particles may be composed of crystal grains.
  • an easy axis of magnetization may be established in a perpendicular direction perpendicular to the surface of the substrate.
  • the diameter of the minute holes may be set in a range of 4 nm to 50 nm, and the depth may be set in an aspect ratio of 2 to 10 nm.
  • a step of preparing a substrate having fine holes drilled on the surface a step of applying a liquid containing fine particles in a specific solvent to the surface of the substrate, Wiping off microparticles overflowing on the surface.
  • the fine particles can flow into the minute holes relatively easily. It can.
  • the microparticles can be uniformly filled in the microholes.
  • a spin coating method or a dipping method may be performed.
  • one of the substrate and the fine particles may be made of a magnetic material, and the other may be made of a non-magnetic material.
  • the diameter of the minute holes may be set to about 4 nm to 50 nm, and the depth may be set to an aspect ratio of 2 to 10 nm.
  • the above-described composite material may be used for a perpendicular magnetic recording medium such as a hard disk (HD), or may be used for other magnetic recording media.
  • a perpendicular magnetic recording medium such as a hard disk (HD)
  • HD hard disk
  • an aggregate of fine particles and a carbon atom existing between the fine particles are provided, and the carbon number is smaller than the total number of atoms constituting the fine particles and the total number of carbon atoms.
  • a structure is provided, wherein the number of atoms alone is set in the range of 45 to 96 atomic%. .
  • the diameter of such fine particles may be set in the range of 1 nm to 30 nm. Minute
  • the particles may be made of a magnetic material containing at least one of Fe, Co, and Ni.
  • the fine particles may include crystal grains.
  • a step of applying an organic solvent containing fine metal particles wrapped with the organic compound to the surface of the object, and subjecting the fine metal particles to an annealing treatment under a vacuum environment after drying the organic solvent The number of carbon atoms in the organic compound is 45 to 96 atomic% with respect to the total number of atoms constituting the fine metal particles and the number of carbon atoms in the organic compound. % Is provided in the range of%.
  • aggregation of the fine metal particles can be avoided by the action of the relatively large amount of the organic compound despite the execution of the annealing treatment.
  • the fine metal particles are maintained as fine crystal grains.
  • Such a manufacturing method may further include a step of subjecting the organic compound to a heat treatment under an inert gas atmosphere prior to performing the annealing treatment. According to such a production method, a flat surface can be established on the surface of the layer composed of the fine metal particles and the organic stabilizer, despite the increase in the amount of the organic stabilizer.
  • a polycrystalline structure film comprising a base layer, fine particles arranged on the surface of the base layer, and a crystal layer including crystal grains that grow based on the fine particles.
  • the crystal grains of the crystal layer grow based on the fine particles. Since the size and dispersion of the fine particles are sufficiently controlled, the size and distribution of the crystal grains in the crystal layer can be reliably controlled. '' In such a polycrystalline film, the fine particles only need to contain a metal element.
  • the diameter of the fine particles may be set in the range of 1 nm to 30 nm.
  • the fine particles may form a continuous layer that extends continuously on the surface of the base layer.
  • Such a polycrystalline structure film can be used for a magnetic recording medium.
  • a magnetic recording medium an underlying polycrystalline layer composed of crystal grains that grow based on fine particles and a magnetic polycrystalline layer composed of crystal grains that grow from individual crystal grains of the underlying polycrystalline layer are stacked. What is necessary is just to form a layer.
  • Such a polycrystalline structure film is used for a perpendicular magnetic recording medium.
  • a magnetic polycrystalline layer composed of crystal grains that grow based on fine particles only needs to be laminated and formed. What is necessary is just to form a layer further.
  • the crystal grains of the underlying polycrystalline layer grow based on fine particles. Since the size and dispersion of the fine particles are sufficiently controlled, the size and distribution of the crystal grains can be reliably controlled in the underlying polycrystalline layer. Since the magnetic polycrystalline layer is composed of crystal grains that grow from individual crystal grains of the underlying polycrystalline layer, the size and distribution of the crystal grains can be reliably controlled. With a magnetic recording medium, the recording density of magnetic information can be increased more than ever.
  • the fine particles may contain a metal element as described above.
  • the diameter of the fine particles may be set in the range of 1 nm to 30 nm.
  • a method for producing microparticles comprising: According to such a production method, since the reducing agent is hardly soluble in the organic solvent, the reducing agent and the organic solvent can be phase-separated. As a result of keeping the polarity of the solution low, aggregation of the fine particles can be sufficiently prevented. Fine and uniform fine particles can be formed relatively easily.
  • the metal compound may be selected from at least one of acetyl acetonate salt, a salt of an organic acid having 1 to 20 carbon atoms, bromide, and iodide.
  • the generated solution may contain two or more kinds of the metal compounds.
  • the organic solvent may be a nonprotonic organic solvent having 6 to 20 carbon atoms. These organic solvents may be selected from hydrocarbons, ethers and esters. A 1,2-diol having 2 to 6 carbon atoms may be used as the reducing agent.
  • the organic stabilizer may include a carboxylic acid R—C OOH.
  • the R in the carboxylic acid C 1 2 H 2 3, ( :. 1 7 11 3 3 Oyobi (2 1 11 4 1 if it is selected from or Re Izu Yoi organic stabilizer Amin R -. may include NH 2 this time, R in Amin is may be selected from any of C 1 3 H 2 5, C 1 8 H 3 5 and C 2 2 H 4 3.
  • the reaction temperature of the solution may be set in the range of 100 t: to 300.
  • FIG. 1 is a plan view schematically showing a specific example of a magnetic recording medium drive, that is, an internal structure of a hard disk drive (HDD).
  • HDD hard disk drive
  • FIG. 2 is an enlarged vertical sectional view showing in detail the structure of the magnetic disk according to the first embodiment of the present invention.
  • FIG. 3 is an enlarged partial cross-sectional view of the substrate schematically showing a step of forming a depression on the surface of the aluminum film.
  • FIG. 4 is an enlarged partial cross-sectional view of the substrate schematically showing a step of forming nanoholes on the surface of the substrate layer.
  • FIG. 5 is an enlarged partial cross-sectional view of the substrate schematically showing a step of applying a liquid containing nanoparticles to the surface of the substrate layer.
  • FIG. 6 is an enlarged partial cross-sectional view of the substrate schematically showing a step of wiping off nanoparticles remaining on the surface of the substrate layer.
  • FIG. 7 is an enlarged vertical sectional view showing in detail the structure of the magnetic disk according to the second embodiment of the present invention.
  • FIG. 8 is an enlarged vertical sectional view of a substrate schematically showing a step of performing a heat treatment on the liquid layer.
  • FIG. 9 is an enlarged vertical sectional view of the substrate schematically showing the structure after the liquid layer has been subjected to the heat treatment.
  • FIG. 10 is a cross-sectional view of an AFM (atomic force microscope) image of a magnetic disk according to a specific example.
  • AFM atomic force microscope
  • FIG. 11 is a cross-sectional view of an AFM image of a magnetic disk according to a comparative example.
  • FIG. 12 is an enlarged vertical sectional view showing in detail the structure of the magnetic disk according to the third embodiment of the present invention.
  • FIG. 13 is an enlarged vertical sectional view showing in detail the structure of a magnetic disk according to a modification of the third embodiment.
  • FIG. 14 is a side view schematically showing the internal structure of the spinco.
  • FIG. 15 is a table showing the relationship between the amount of the metal compound used and the composition ratio of the nanoparticles.
  • FIG. 1 schematically shows a specific example of a magnetic recording medium drive, that is, an internal structure of a hard disk drive (HDD) 11.
  • the HDD 11 includes, for example, a box-shaped housing main body 12 that partitions an internal space of a flat rectangular parallelepiped.
  • One or more magnetic disks 13 as a magnetic recording medium are accommodated in the accommodation space.
  • the magnetic disk 13 is mounted on a rotating shaft of a spindle motor 14.
  • the spindle motor 14 can rotate the magnetic disk 13 at a high speed such as, for example, 720 rpm or 1000 rpm.
  • the housing body 12 is connected with a lid (not shown) for sealing the accommodation space between the housing body 12 and the housing body 12.
  • a head shaft 16 extending vertically is fitted with a head actuator 16.
  • the head actuator 16 is composed of a rigid actuator arm 17 extending horizontally from the support shaft 15 and an actuator 17 attached to the tip of the actuator arm 17.
  • An elastic suspension 18 extending forward is provided.
  • the flying head slider 19 is cantilevered at the tip of the elastic suspension 18 by a so-called gimbal spring (not shown).
  • a pressing force is applied to the flying head slider 19 from the elastic suspension 18 toward the surface of the magnetic disk 13.
  • buoyancy acts on the flying head slider 19 by the action of the airflow generated on the surface of the magnetic disk 13. Due to the balance between the pressing force of the elastic suspension 18 and the buoyancy, the flying head slider 19 can keep flying with relatively high rigidity during the rotation of the magnetic disk 13.
  • a magnetic head that is, an electromagnetic transducer (not shown) is mounted on the flying head slider 19.
  • This electromagnetic transducer is, for example, a giant magnetoresistive (GMR) element or a tunnel junction magnetoresistive (TMR) element that reads information from a magnetic disk 13 by using the resistance change of a spin valve film or a tunnel junction film.
  • GMR giant magnetoresistive
  • TMR tunnel junction magnetoresistive
  • Element A read element and a write element such as a single magnetic pole head and an inductive write head that write information on the magnetic disk 13 using the magnetic field generated by the thin film coil pattern.
  • the flying head slider 19 can cross the surface of the magnetic disk 13 in the radial direction. Based on such movement, the electromagnetic transducer on the flying head slider 19 is positioned at a desired recording track on the magnetic disk 13.
  • the rotation of the head actuator 16 may be realized through the operation of the drive source 21 such as a voice coil motor (VCM).
  • VCM voice coil motor
  • FIG. 2 shows a cross-sectional structure of the magnetic disk 13 according to the first embodiment of the present invention in detail.
  • This magnetic disk 13 is configured as a so-called perpendicular magnetic recording medium.
  • the magnetic disk 13 includes a substrate 31 as a support, and a multilayer structure film 32 extending on the front and back surfaces of the substrate 31.
  • Substrate 3 1 are, for example, the S i body 3 3 of the disc-shaped, may be made by the S i body 3 amorphous extending 3 on the front and back surfaces S i 0 2 film 3 4.
  • a glass substrate, an aluminum substrate, or a ceramic substrate may be used as the substrate 31.
  • Magnetic information is recorded on the multilayer structure film 32.
  • the surface of the multilayer structure film 32 is covered with a protective film 35 such as a diamond-like carbon (DLC) film and a lubricating film 36 such as a perfluoropolyether (PFPE) film.
  • DLC diamond-like carbon
  • PFPE
  • the multilayer structure film 32 includes a backing layer 37 extending on the surface of the substrate 31.
  • the backing layer 37 may be made of a soft magnetic material such as a FeTaC film or a NiFe film.
  • a FeTaC film having a thickness of about 20 O nm, for example, may be used for the backing layer 37.
  • an easy axis is established in an in-plane direction defined in parallel with the surface of the substrate 31.
  • the intermediate layer 38 extends on the surface of the backing layer 37.
  • the intermediate layer 38 may be made of a nonmagnetic material such as an aluminum film.
  • the composite material, that is, the recording magnetic layer 39 is spread on the surface of the intermediate layer 38.
  • the recording magnetic layer 39 is formed by a substrate extending on the surface of the intermediate layer 38.
  • the body or substrate layer 41 is provided.
  • the substrate layer 4 1 may be employed such as alumina (A 1 2 ⁇ 3) and when was the non-magnetic material.
  • Micro holes, ie, nano holes 42 are formed in the surface of the substrate layer 41.
  • the nanoholes 42 are regularly arranged on the surface of the substrate layer 41.
  • the nanoholes 42 may be arranged, for example, along rows that are parallel at equal intervals in the circumferential direction of the substrate 31. In each row, the nanoholes 42 may be arranged at an interval equal to the interval between the rows.
  • the distance between the nanoholes 42 may be set to, for example, about 4 nm to 30 nm.
  • the diameter of the nanohole 42 may be set to about 4 nm to 50 nm.
  • the depth of the nanoholes 42 may be set based on an aspect ratio of 2 to 10. The aspect ratio indicates the ratio of the depth to the diameter of the nanohole 42.
  • Microparticles that is, nanoparticles 43 are arranged in the nanoholes 42.
  • the nanoparticles 43 contain a metal element.
  • the nanoparticles 43 need only include at least one of magnetic materials such as Fe, Co, and Ni.
  • the nanoparticles 43 may further include materials such as Cr, Pt, and Pd.
  • a magnetic FePt alloy may be used for the nanoparticles 43.
  • These nanoparticles 43 are composed of crystal grains.
  • an easy axis is established in a vertical direction perpendicular to the surface of the substrate layer 41.
  • the surface of the crystal grain is wrapped in a carbon atom (not shown).
  • carbon atoms individual grains can exist alone within nanoholes 42.
  • the crystal grains may fuse within the nanohole 42.
  • the surface of the fused grains is enveloped by carbon atoms.
  • the particle size of the nanoparticles 43 is always set to a smaller particle size than the diameter of the nanoholes 42 described above.
  • the particle size of the nanoparticles 43 may be set based on, for example, a ratio of about one-fifth to one-half of the diameter of the nanoholes 42.
  • the ratio of the standard deviation ⁇ of the particle size distribution to the average particle size D of the nanoparticles 43, that is, the particle size variance ⁇ ZD may be set to 10% or less.
  • the spacing between nanoparticles 43 within nanohole 42 is 0.2 ⁇ ! It may be set to about 5.0 nm.
  • the protective film 35 is formed on the surface of the substrate layer 41.
  • the nanoparticles 43 are confined in the nanoholes 42. That is, the protective film 35 functions as a coating layer.
  • the nanoparticles 43 are It is completely contained in the nanohole 42.
  • the nanoparticles 43 are arranged only in the nanoholes 42 and are not arranged on the surface of the substrate layer 41.
  • the direction of magnetization of the recording magnetic layer 39 can be specified based on the nanoparticles 43.
  • the nanoparticles 43 can be regularly arranged based on the nanoholes 42.
  • the outline can be clearly drawn for each individual magnetization region. So-called transition noise is suppressed.
  • the recording density of magnetic information can be reliably increased.
  • a method of manufacturing the magnetic disk 13 will be described in detail.
  • a disk-shaped substrate 31 is prepared.
  • a backing layer 37 and an aluminum layer are sequentially formed on the surface of the substrate 31.
  • a sputtering method or a vacuum evaporation method may be used.
  • nanoholes 42 are formed based on the aluminum layer.
  • the surface of the aluminum layer is oxidized.
  • the intermediate layer 38 and the substrate layer 41 are formed from the aluminum layer. Details of the method for forming the nanoholes 42 will be described later.
  • the substrate 31 is set in an annealing chamber. Within the chamber 3 X 1 0 _ 5 [P a] following the vacuum environment is established.
  • the temperature in the chamber may be set in the range of 200 ° C. to 900 ° C. For example, a temperature of 800 ° C. may be maintained for 30 minutes.
  • the temperature in the chamber is 800 from room temperature. It only has to rise to C in 10 minutes.
  • a predetermined magnetic field is applied to the nanoparticles 43.
  • the magnitude of the magnetic field may be set, for example, in the range of 0.1 to: L 0.0 [T].
  • the direction of the axis of easy magnetization is controlled by each of the nanoparticles 43.
  • the substrate 31 is cooled to room temperature.
  • a protective film 35 and a lubricating film 36 are formed on the surface of the substrate layer 41.
  • the protective film 35 may be formed by, for example, a sputtering method.
  • the lubricating film 36 may be applied based on, for example, a dipping method.
  • a method for forming the nanoholes 43 will be described in detail.
  • a rectangular pattern 45 is pressed on the surface of the aluminum film 44 on the substrate 31.
  • Protrusions 46 are formed at predetermined intervals on the surface of the cymbal shape 45.
  • Aluminum based on pressing of protrusions 4 and 6 Fine depressions 47 are formed on the surface of the film 45.
  • anodization is performed on the aluminum film 44.
  • the aluminum film 44 is immersed in an aqueous solution.
  • aqueous solution For example, 0.5 [M] of a shinic acid aqueous solution at 25 ° C is used as the aqueous solution.
  • the applied voltage is set to, for example, 40 [V].
  • the aluminum film 44 is oxidized from the surface based on the anodizing reaction.
  • the nanoholes 42 grow from the depressions 47 described above.
  • nanoholes 42 are formed on the surface of the substrate layer 41.
  • the substrate layer 41 is immersed in a phosphoric acid solution.
  • the inner peripheral surface of the nanohole 42 is etched based on the reaction with the phosphoric acid solution.
  • the diameter of the nanohole 42 is set to, for example, about 10 nm.
  • the depth of the nanoholes 42 is set to about 3 O nm.
  • the portion that is not anodized forms an aluminum intermediate layer 38.
  • the well-known super hydride method / polyol method may be used for the formation of the nanoparticles 43.
  • the diameter of the nanoparticles 43 is set to, for example, about 7 nm.
  • the individual nanoparticles 43 thus formed are enveloped with an organic compound, ie an organic stabilizer.
  • the organic stabilizer may be composed of, for example, carboxylic acid R—CO OHamine R—NH 2 .
  • R may be a linear or branched alkyl or alkenyl hydrocarbon.
  • the nanoparticles 43 wrapped in the organic stabilizer are added to a specific organic solvent.
  • the nanoparticles 43 redisperse in the organic solvent.
  • An organic solvent such as hexane, heptane or octane may be used for redispersion.
  • the substrate layer 41 having the aforementioned nanoholes 42 is prepared.
  • the formed nanoparticles 43 are filled in the nanoholes 42.
  • a liquid containing nanoparticles 43 wrapped in an organic stabilizer is applied to the surface of the base layer 41.
  • a spin coating method or a dipping method may be applied to the application.
  • the nanoparticles 43 overflowing from the nanoholes 42 to the surface of the substrate layer 41 are wiped off.
  • the substrate 31 is rotated.
  • a wiper 49 is pressed against the surface of the substrate layer 41.
  • the wiper 49 may be made of an elastic material such as rubber.
  • the nanoparticles 43 remaining on the surface of the substrate layer 41 based on the wiper 49 are reliably wiped off. like this As a result, the nanoparticles 43 are completely contained in the nanoholes 42.
  • the liquid containing the nanoparticles 43 in a specific solvent is applied to the surface of the substrate layer 41, so that the nanoparticles 43 are relatively easily formed. It can flow into the nanoholes 42. In addition, the nanoparticles 43 overflowing from the minute holes 42 to the surface of the substrate layer 41 are wiped off. The magnetic nanoparticles 43 can remain only in the nanoholes 42.
  • the recording magnetic layer 39 may be composed of the nonmagnetic substrate layer 41 and the magnetic nanoparticles 43 as described above.
  • the substrate layer 41 may be made of a magnetic material
  • the nanoparticles 43 may be made of a non-magnetic material.
  • one of the substrate layer 41 and the nanoparticles 43 may be made of a conductor, and the other may be made of an insulator.
  • FIG. 7 shows a detailed cross-sectional structure of the magnetic disk 13a according to the second embodiment of the present invention.
  • This magnetic disk 13a is configured as a so-called perpendicular magnetic recording medium.
  • the magnetic disk 13a includes a substrate 51 as a support, and a multilayer structure film 52 extending on the front and back surfaces of the substrate 51.
  • Substrate 5 for example, the S i body 3 of the disk-shaped, may be made by the S i amorphous S I_ ⁇ 2 film 5 4 over the front and back surfaces of the main body 3.
  • a glass substrate, an aluminum substrate, or a ceramic substrate may be used as the substrate 51.
  • Magnetic information is recorded on the multilayer structure film 52.
  • the surface of the multilayer structure film 52 is covered with a protective film 55 such as a diamond-like carbon (DLC) film and a lubricating film 56 such as a perfluoropolyether (PFPE) film.
  • DLC diamond-like carbon
  • PFPE perfluor
  • the multilayer structure J3 includes a backing layer 57 extending on the surface of the substrate 51.
  • the backing layer 57 may be made of a soft magnetic material such as a FeTaC film or a NiFe film.
  • the backing layer 57 has a thickness of, for example, about 200] 111?
  • an easy axis is established in an in-plane direction defined in parallel with the surface of the substrate 51.
  • the intermediate layer 58 spreads on the surface of the backing layer 57.
  • the intermediate layer 58 may be made of a non-magnetic material such as a carbon film.
  • a carbon film having a thickness of about 5 nm may be used for the intermediate layer 58.
  • the structure, that is, the recording magnetic layer 59 is spread on the surface of the intermediate layer 58.
  • the thickness of the recording magnetic layer 59 may be set to, for example, about 30 nm.
  • the recording magnetic layer 59 includes an aggregate of fine particles, that is, nano metal particles 61, which spread on the surface of the intermediate layer 58.
  • the nano metal particles 61 may be made of, for example, magnetic fine metal particles containing at least one of Fe, Co, and Ni.
  • nano metal particles 61 materials such as Pt and Pd may be added to the nano metal particles 61.
  • materials such as Pt and Pd may be added to the nano metal particles 61.
  • a magnetic FePt alloy may be used for the nano metal particles 61.
  • These nano metal particles 61 are composed of crystal grains. In each crystal grain, an easy axis of magnetization is established in a perpendicular direction perpendicular to the surface of the substrate 51.
  • the diameter of the nano metal particles 61 may be set, for example, in the range of 2 nm to 10 nm.
  • the distance between the nano metal particles 61 may be set in the range of 0.2 nm to 5.0 nm.
  • The ratio of the standard deviation ⁇ of the particle size distribution to the average particle size D of the nano metal particles 61 That is, the particle size distribution ⁇ ZD may be set to 10% or less.
  • the recording magnetic layer 59 carbon atoms 62 exist between the nano metal particles 61.
  • the carbon atoms 62 link the nanometal particles 61 together.
  • the number of atoms of carbon atoms 62 alone is 45 atomic% to 96% of the total number of atoms constituting the nano metal particles 61 and the total number of carbon atoms 62. It is set in the range of atomic%.
  • a sputtering method or a vacuum evaporation method may be used.
  • an aggregate of nano metal particles 61 is formed on the surface of the intermediate layer 58. Details of the formation method will be described later.
  • a protective film 55 and a lubricating film 56 are formed on the surface of the aggregate of the nano metal particles 61.
  • a sputtering method may be used to form the protective film 55.
  • the lubricating film 56 may be applied based on, for example, a dip method.
  • a liquid containing the nanometal particles 61 in an organic solvent such as hexane is prepared.
  • the nano metal particles 61 may be made of, for example, an FePt alloy.
  • the diameter of the nano metal particles 61 is set to, for example, about 7 nm.
  • Individual nanometal particles 61 are wrapped with an organic compound or organic stabilizer. It is.
  • the organic stabilizer may be composed of, for example, a carboxylic acid R — C ⁇ Hamine R — NH 2 .
  • a linear or branched alkyl or alkenyl hydrocarbon may be used for R.
  • the number of carbon atoms in the organic stabilizer is in the range of 45 atomic% to 96 atomic% with respect to the total number of atoms constituting the fine metal particles and the number of carbon atoms in the organic compound. Is set by
  • the nano metal particles 61 and the organic stabilizer are coated on the surface of the intermediate layer 58 together with the organic solvent.
  • a spin coating method or a dipping method may be used. Thereafter, the organic solvent is dried.
  • the nano metal particles 61 and the organic stabilizer remain on the surface of the intermediate layer 58.
  • the distribution of the nanometal particles 61 is shaded. Irregularities are formed on the surface of the liquid layer 63 composed of the nanometal particles 61 and the organic stabilizer.
  • the surface of the intermediate layer 58 is subjected to a heat treatment.
  • the organic stabilizer is exposed to a high temperature such as 100 ° C. to 300 ° C. in an atmosphere of an inert gas such as nitrogen gas.
  • the heat treatment is continued for, for example, 1 minute to 60 minutes.
  • the distribution of the nano metal particles 61 is uniformly distributed on the surface of the intermediate layer 58.
  • a flat surface is established on the surface of the liquid layer 63 composed of the nano metal particles 61 and the organic stabilizer. Unevenness is eliminated.
  • an annealing treatment is applied to the nano metal particles 61 in a vacuum environment.
  • the substrate 51 is set in an annealing chamber.
  • a vacuum environment of 3 xl O- 5 [Pa] or less is established in the chamber.
  • the temperature inside the champer is 200 ° C to 900 ° C. What is necessary is just to set in the range of C. For example, a temperature of 800 ° C. may be maintained for 30 minutes.
  • the temperature in the chamber may be raised from room temperature to 800 in 10 minutes.
  • a predetermined magnetic field is applied to the nanometal particles 61.
  • the magnitude of the magnetic field may be set, for example, in the range of 0.1 to 10.0 [T].
  • the individual nano metal particles 61 crystallize based on the heating. By the action of the magnetic field, the easy axis of the nano metal particles 61 is aligned in a predetermined direction. Thereafter, the substrate 51 is cooled to room temperature. According to the above-described production method, the aggregation of the nano metal particles 61 can be avoided by the action of the relatively large amount of the organic stabilizer despite the execution of the annealing treatment.
  • the nano metal particles 61 are maintained as fine crystal grains. So-called magnetic domains are refined. Miniaturization of magnetic domains greatly contributes to improvement of recording density.
  • the flying head slider 19 can reliably continue to fly in a stable posture.
  • the present inventor observed an aggregate of nano metal particles 61 based on an image of FE-SEM (field emission scanning electron microscope).
  • the first specific example and the first comparative example were prepared.
  • a larger amount of the organic stabilizer than before was arranged around the nano metal particles 61.
  • a small amount of the organic stabilizer was disposed around the nanometal particles 61 in the same manner as in the past when applying the nanometal particles 61 and the organic stabilizer.
  • “small amount” means the maximum number of molecules attached around each individual nano metal particle 61.
  • the nano metal particles 61 were subjected to an annealing treatment as described above. As a result of the observation, it was confirmed that fine nano metal particles 61, that is, crystal grains were maintained in the first specific example. However, relatively large unevenness was observed on the surface of the aggregate of the nanometal particles 61. On the other hand, in the first comparative example, it was confirmed that although the flat surface was maintained on the surface of the aggregate of the nanometal particles 61, the crystal grains were enlarged based on the coalescence of the nanometal particles 61. . .
  • the present inventors observed the surface of the liquid layer 63 composed of the nanometal particles 61 and the organic stabilizer at the time of the application of the nanometal particles 61 and the organic stabilizer.
  • the first specific example and the first comparative example were used for observation.
  • irregularities were observed on the surface of the liquid layer 63. Therefore, it was demonstrated that these irregularities were maintained before and after the annealing treatment.
  • a flat surface was secured on the surface of the liquid layer 63 composed of the nanometal particles 61 and the organic stabilizer.
  • the present inventor has developed nano metal particles 6 1 based on AFM (atomic force microscope) images. Was observed.
  • AFM atomic force microscope
  • a second specific example and a second comparative example were prepared.
  • a larger amount of the organic stabilizer was disposed around the nanometal particles 61 than before in the application of the nanometal particles 61 and the organic stabilizer.
  • the annealing treatment was performed on the nano metal particles 61 in all the samples.
  • the above-described heat treatment was performed prior to the annealing treatment.
  • the nanometal particles 61 and the organic stabilizer were exposed to a high temperature of 200 ° C. for 5 minutes under a nitrogen atmosphere.
  • the second comparative example an annealing treatment was performed after the application of the nanometal particles 61 and the organic stabilizer. That is, in the second comparative example, the above-described heat treatment was not performed.
  • FIG. 10 in the second specific example, a flat surface was secured on the surface of the aggregate of the nano metal particles 61. A surface roughness Ra of 44 pm over a 1 m square was recorded. As is clear from FIG. 11, irregularities were formed on the surface of the aggregate of the nano metal particles 61 in the second comparative example. 1; surface roughness Ra of 0.909 pm on m squares was recorded.
  • the present inventor observed the aggregate of the nano metal particles 61 based on the FE-SEM image as described above.
  • Three types of samples were prepared for observation.
  • a larger amount of the organic stabilizer was disposed around the nanometal particles 61 than before in the application of the nanometal particles 61 and the organic stabilizer as in the first specific example described above.
  • the nano metal particles 61 were subjected to an annealing treatment as described above.
  • the heat treatment described above was performed prior to the annealing treatment in all samples. The heating time was set to 5 minutes, 30 minutes and 45 minutes for each sample.
  • FIG. 12 shows a cross-sectional structure of a magnetic disk 13b according to the third embodiment of the present invention in detail.
  • This magnetic disk 13b is configured as an in-plane magnetic recording medium.
  • the magnetic disk 13 b includes a substrate 71 as a support, and a polycrystalline structure film 72 extending on the front and back surfaces of the substrate 71.
  • the substrate 71 may be made of, for example, a glass substrate. However, the substrate 71 may be an aluminum substrate, a silicon substrate, or a ceramic substrate. May be used. Magnetic information is recorded on the polycrystalline structure film 72.
  • the surface of the polycrystalline structure film 72 is covered with a protective film 73 such as a diamond-like carbon (DLC) film and a lubricating film 74 such as a perfluoropolyether (PFPE) film.
  • DLC diamond-like carbon
  • PFPE perfluoropolyether
  • the polycrystalline structure film 72 includes fine particles, that is, nanoparticles 75 disposed on the surface of the base layer, that is, the substrate 71.
  • the nanoparticles 75 form a continuous layer that extends continuously on the surface of the substrate 71.
  • the thickness of the continuous layer of the nanoparticles 75 may be set to, for example, about 20 nm.
  • the nanoparticles 75 contain a metal element.
  • Such metal elements may include, for example, Fe and Pt.
  • an Fe Pt alloy may be used for the nanoparticles 75.
  • the diameter of the nanoparticles 75 may be set in the range of 2 nm to 10 nm.
  • the ratio of the standard deviation of the particle size distribution to the average particle size D of the nanoparticles 75, that is, the particle size distribution ⁇ / D may be set to 20% or less.
  • an adhesion layer 76 may be interposed between the substrate 71 and the nanoparticles 75.
  • a carbon film can be used for such an adhesion layer 76. According to the function of the adhesive film 76, the adhesive force between the substrate 71 and the nanoparticles 75 can be increased.
  • the underlying polycrystalline layer 77 spreads on the surface of the nanoparticles 75.
  • the underlying polycrystalline layer 77 is composed of crystal grains that grow based on the nanoparticle 75.
  • Base polycrystalline layer 77 may be made of, for example, an alloy containing ⁇ t and Pd.
  • a PtPd film having a thickness of about 5 nm is used for the underlying polycrystalline layer 77.
  • the magnetic polycrystalline layer 78 spreads on the surface of the base polycrystalline layer 77.
  • Magnetic polycrystalline layer 78 is composed of crystal grains that grow from individual crystal grains of base polycrystalline layer 77. Magnetic information is recorded on the magnetic polycrystalline layer 78.
  • the magnetic polycrystalline layer 78 may be made of, for example, an alloy containing at least one of Co, Ni, and Fe. Here, for example, a CoCrPt film having a thickness of about 15 nm is used.
  • the crystal grains of the underlying polycrystalline layer 77 grow based on the nanoparticles 75. Since the size and dispersion of the nanoparticles 75 are sufficiently controlled, the size and distribution of crystal grains in the underlying polycrystalline layer 77 can be reliably controlled.
  • the magnetic polycrystalline layer 7 8 is composed of crystal grains that grow from the individual crystal grains of the underlying polycrystalline layer 7 7. Therefore, the size and distribution of the crystal grains can be reliably controlled. In the magnetic disk 13b, the recording density of magnetic information can be increased more than ever.
  • a method of manufacturing the magnetic disk 13b will be briefly described.
  • a disk-shaped substrate 71 is prepared.
  • An adhesion layer 76 of carbon is formed on the surface of the substrate 71.
  • a vacuum evaporation method is used.
  • the thickness of the adhesion layer 76 may be set to, for example, about 4 nm.
  • Nanoparticles 75 are applied to the surface of the adhesion layer 76 based on a so-called spin coating method.
  • the substrate 71 is driven at a rotation speed of 300 rpm. Thereafter, the substrate 71 is placed in, for example, a hexane atmosphere. Subsequently, the rotation speed of the substrate 71 is reduced to 60 rpm. At this time, a liquid containing nanoparticles is dropped on the surface of the substrate 71 in an organic solvent. After the dropping, the rotation speed of the substrate 71 is increased to 1000 rpm. As a result of the rotation of 100 rpm being maintained for 10 seconds, the dropped liquid uniformly spreads over the surface of the substrate 71 without being tight.
  • the surface of the substrate 71 is exposed to a nitrogen gas atmosphere.
  • the hexane remaining on the surface of the substrate 71 is dried by the action of nitrogen gas.
  • a continuous film of the nanoparticles 75 is formed.
  • the nanoparticles 75 are arranged in a regular array based on so-called self-organization.
  • the substrate 71 is mounted on a sputtering device. Sputtering is performed based on the PdPt target. As a result, a PdPt alloy film, that is, an underlying polycrystalline layer 77 is formed. In the base polycrystalline layer 77, individual crystal grains grow based on the nanoparticles 75.
  • the thickness of underlying polycrystalline layer 77 may be set to, for example, about 5 nm.
  • Magnetic polycrystalline layer 78 is formed on base polycrystalline layer 77.
  • the crystal grains of the magnetic polycrystalline layer 78 grow from the crystal grains of the underlying polycrystalline layer 77 based on the epitaxial growth.
  • the thickness of the magnetic polycrystalline layer 78 may be set to, for example, about 15 nm.
  • a flask is prepared. In the flask are placed 197 mg (equivalent to 0.5 mM) of bis-acetylacetonato platinum and 39 Omg of 1,2-hexadecanediol. The flask is charged with 20 mL (milliliter) of octyl ether. Then, 0.32 mL (equivalent to 1. OmM) of oleic acid and 0.34 mL (equivalent to 1.0 mM) of oleylamine are added to the flask. Subsequently, 0.13 mL (equivalent to 1.
  • OmM of iron carbonyl Fe (CO) 5 is added to the flask.
  • the solution thus formed in the flask is stirred at a temperature of 230 ° C.
  • a diversion reaction occurs in the solution.
  • Iron platinum (FePt) nanoparticles are produced.
  • the nanoparticles are encapsulated in an organic stabilizer such as oleylamine oleate.
  • FIG. 13 shows a detailed cross-sectional structure of a magnetic disk 13c according to a modification of the third embodiment of the present invention.
  • the magnetic disk 13c is configured as a so-called perpendicular magnetic recording medium.
  • the magnetic disk 13c includes a substrate 91 as a support, and a polycrystalline structure film 92 extending on the front and back surfaces of the substrate 91.
  • the polycrystalline structure film 92 includes a backing layer 95 extending on the surface of the substrate 91.
  • the backing layer 95 may be made of a soft magnetic material such as a FeTaC film or a NiFe film.
  • an FeTaC film having a film thickness of about 20 Onm may be used for the backing layer 95.
  • an easy magnetic axis is established in an in-plane direction defined parallel to the surface of the substrate 91.
  • the polycrystalline structure film 92 includes microparticles or nanoparticles 96 disposed on the surface of the base layer or backing layer 95.
  • the nanoparticles 96 form a continuous layer, ie, a non-magnetic layer, that extends continuously on the surface of the backing layer 95.
  • the thickness of the continuous layer of the nanoparticles 96 may be set to, for example, about 20 nm.
  • the diameter of the nanoparticles 96 may be set in the range of 2 nm to 10 nm.
  • the ratio of the standard deviation ⁇ of the particle size distribution to the average particle size D of the nanoparticles 96, that is, the particle size distribution ⁇ / D may be set to 20% or less.
  • the magnetic polycrystalline layer 97 spreads on the surface of the nanoparticles 96.
  • the magnetic polycrystalline layer 97 is composed of crystal grains that grow based on the nanoparticle 96. Magnetic information is recorded on the magnetic polycrystalline layer 97.
  • the magnetic polycrystalline layer 97 may be made of, for example, an alloy containing at least one of Co, Ni, and Fe. In this case, for example, C 0 CrPt Ji-dian having a thickness of about 15 nm is used. In the magnetic polycrystalline layer 97, an easy axis of magnetization is established in a perpendicular direction perpendicular to the surface of the substrate 91.
  • an orientation control layer 98 may be interposed between the substrate 91 and the backing layer 95.
  • an orientation control layer 98 for example, Cr or an alloy film containing Cr can be used. According to the function of the orientation control film 98, the orientation of the crystal grains of the magnetic polycrystalline layer 98 can be sufficiently aligned.
  • the crystal grains of the magnetic polycrystalline layer 97 are elongated based on the nanoparticles 96. Since the size and dispersion of the nanoparticles 96 are sufficiently controlled, the size and distribution of crystal grains in the magnetic polycrystalline layer 97 can be reliably controlled.
  • a method of manufacturing the magnetic disk 13c will be briefly described.
  • a disk-shaped substrate 91 is prepared.
  • the orientation control layer 98 and the backing layer 96 may be formed on the substrate 91.
  • a sputtering method is used.
  • nanoparticles 96 are applied to the surface of the backing layer 96 based on a so-called spin coating method. A continuous film of nanoparticles 96 is formed. The nanoparticles 96 are arranged in a regular array based on the so-called self-organization.
  • the substrate 91 is mounted on a sputtering apparatus. Sputtering is performed based on the CoCrPt target. As a result, a CoCrPt alloy film, that is, a magnetic polycrystalline layer 97 is formed. In the magnetic polycrystalline layer 97, individual crystal grains grow based on the nanoparticles 96.
  • the thickness of the magnetic polycrystalline layer 97 may be set to, for example, about 15 nm.
  • FIG. 14 schematically shows the configuration of the spinco.
  • This spinco 101 has a sealed chamber 102.
  • a rotation axis 103 is arranged in the chamber 102.
  • a magnetic disk 13 (13a, 13b, 1 3 c) is accepted. With the rotation of the rotating shaft 103, the magnetic disk 13 can rotate around the central axis.
  • the first and second drip nozzles 104 and 105 face the space in the chamber 103.
  • the tip of the first dripping nozzle 104 faces the surface of the magnetic disk 13 mounted on the rotating shaft 103.
  • the first dropping nozzle 104 can move in a horizontal direction along one vertical plane including the center axis of the rotation axis 103. That is, the first dropping nozzle 104 can move in the radial direction of the magnetic disk 13 mounted on the rotating shaft 103.
  • a liquid is supplied to the first dripping nozzle 104, for example, from a predetermined liquid reservoir. Based on the combination of the rotation of the rotating shaft 103 and the horizontal movement of the first dropping nozzle 104, the liquid can be dropped on the magnetic disk 13 along, for example, a spiral path.
  • the liquid containing nanoparticles in the organic solvent may be supplied to the first dropping nozzle 104 as described above.
  • a vaporizer 106 is opposed to the tip of the second drip nozzle 105.
  • the liquid dropped from the second dropping nozzle 105 is received by the vaporizer 106.
  • the inside of the channel 102 can be filled with a gas to be vaporized by the vaporizer 106.
  • the vapor pressure of the vaporized gas is detected by the vapor pressure sensor 107.
  • the amount of the liquid dropped from the second dropping nozzle 105 can be adjusted based on the detected vapor pressure.
  • a hexane atmosphere can be established in the chamber 102 by the operation of the second dropping nozzle 105.
  • a gas inlet 108 is formed in the chamber 102.
  • the gas inlet 108 is opposed to the surface of the magnetic disk 13 mounted on the rotating shaft 103. Based on the function of the gas inlet 108, nitrogen gas can be ejected toward the surface of the magnetic disk 13 as described above.
  • a drain 109 is connected to the chamber 102. Excess liquid can be drained from the drain 109 out of the chamber 102.
  • the nanoparticles 43, 61, 75, and 96 may be produced by, for example, the following production method.
  • a nonvolatile metal compound is prepared.
  • the metal compound for example, acetyl acetonato salt can be used.
  • salts of organic acids selected from carboxylic acid salts, hydrocyanic acid salts, sulfonic acid salts, and phosphonic acid salts are used. May be. In these organic acid salts, the carbon number is set in the range of 1-20.
  • bromides and iodides can be used as the metal compound.
  • the metal element contained in such a metal compound may include, for example, Fe, Co, Ni, Pt, Cr, Cu, Ag, Mn and Pb.
  • two or more metal compounds may be included.
  • a specific organic solvent is prepared.
  • aprotic organic solvents such as hydrocarbons, ethers and esters can be used.
  • the ether includes, for example, dioctyl ether.
  • 1,2-diol can be used as the reducing agent.
  • the number of carbon atoms may be set in the range of 2 to 6.
  • 1,2-diols include, for example, 1,2-butanediol.
  • Organic stabilizers are provided for nanoparticle formation.
  • Organic stabilizers include, for example, the carboxylic acid R-COOH.
  • R in such a carboxylic acid may be selected from a linear hydrocarbon group containing a double bond.
  • Such a linear hydrocarbon group may be selected from, for example, any one of C 12 H 23 , C 17 H 33 and C 21 H 41 .
  • the organic stabilizer may include, for example, amine R—NH 2 .
  • R in such an amine may be similarly selected from a linear hydrocarbon group containing a double bond.
  • Such a linear hydrocarbon group may be selected, for example, from any of C 13 H 25 , C 18 H 35 and C 22 H 43 .
  • the organic stabilizer may include one or both of the carboxylic acid R—COOH and the amine R—NH 2 .
  • the flask is prepared in an atmosphere of an inert gas such as nitrogen gas or argon gas.
  • an inert gas such as nitrogen gas or argon gas.
  • the above-mentioned metal compound, organic solvent, reducing agent and organic stabilizer are mixed to form a solution.
  • the solution thus formed in the flask is stirred at a predetermined reaction temperature.
  • the reaction temperature is set, for example, in the range of 100 ° C to 300 ° C.
  • the metal is reduced from the metal compound in the solution based on the reducing agent.
  • nanoparticles are formed.
  • the nanoparticles are encapsulated in organic stabilizers such as oleylamine phosphate. Thereafter, the solution in the flask is cooled to room temperature.
  • a solvent such as ethanol is added into the flask.
  • the precipitate of nanoparticles and organic stabilizer is removed based on centrifugation.
  • the extracted nanoparticles and organic stabilizer are put into an organic solvent such as hexane.
  • nanoparticles dispersed in the hexane solution are obtained.
  • the reducing agent 1,2-diol is hardly soluble in aprotic organic solvents such as hydrocarbons, ethers, and esters, so that the reducing agent and the organic solvent are phase-separated.
  • aprotic organic solvents such as hydrocarbons, ethers, and esters
  • the present inventors manufactured iron platinum (FePt) nanoparticles based on the above-described manufacturing method.
  • the flask was prepared under an argon gas atmosphere.
  • a metal compound ie, 197 mg (0.5 mM equivalent) of platinum (II) acetyl acetate and 177 mg (0.5 mM equivalent) of iron (III) acetyl acetate were placed.
  • To the flask was added 1 OmL of an organic solvent, octyl ether.
  • the flask was charged with 0.9 mL of the reducing agent, ie, 1,2-butanediol.
  • an organic stabilizer 0.16 mL (equivalent to 0.05 mM) of oleic acid and 0.17 mL (equivalent to 0.5 mM) of oleylamine were added to the flask.
  • the solution thus formed in the flask was stirred at a temperature of 190 ° C for 30 minutes. Thereafter, the solution in the flask was cooled to room temperature. 1 OmL of ethanol was added to the flask. The precipitate of nanoparticles and organic stabilizer was removed based on centrifugation. The extracted nanoparticles and organic stabilizer were injected into a hexane solution. Thus, FePt nanoparticles dispersed in the hexane solution were obtained.
  • the present inventors have verified the FePt nanoparticles formed as described above. As a result, it was confirmed that the average particle size of the FePt nanoparticles was about 2.9 nm. That is, it was confirmed that very fine and uniform nanoparticles were formed. It was confirmed that the composition ratio Fe: Pt of the FePt nanoparticles was 45:55 [%].
  • the present inventors examined the relationship between the amount of the metal compound used and the composition ratio of the nanoparticles.
  • platinum (II) acetate Ruacetonato and iron (III) acetilacetonato were used.
  • the inventor changed the amount of each metal compound used.
  • the composition ratio of Fe Pt nanoparticles can reflect the ratio of the amount of platinum (II) acetyl acetonato used to the amount of iron (III) acetyl acetonato used. confirmed. That is, according to the above-described production method, the composition ratio of the metal in the nanoparticles can be controlled based on the amount of the metal compound used.
  • platinum (II) acetyl acetonate is composed of platinum (II) acetate, platinum benzoate (11), platinum cyanide (11), platinum benzenesulfonate ( I 1), platinum propylphosphonate (1 1), platinum bromide (1 1), and platinum iodide (II) were confirmed to be replaced.
  • iron (III) acetyla settonate is composed of iron (III) acetate, iron benzoate (111), iron cyanide (111), iron benzenesulfonate (II1), iron propylphosphonate (II).
  • the present inventors produced nanoparticles based on platinum (II) acetyl acetonato, iron (III) acetyl acetonato and bis (acetyl acetonato copper) according to the above-mentioned production method.
  • platinum (II) acetyl acetonato, iron (III) acetyl acetonato and bis (acetyl acetonato copper) according to the above-mentioned production method.
  • white gold-iron-copper (FePtCu) nanoparticles with an average particle size of 2.7 nm to 3.5 nm were obtained. It was confirmed that the composition ratio of the platinum-iron-copper nanoparticles reflects the amount of each metal compound used.
  • the present inventors produced nanoparticles based on platinum (II) acetyl acetonato, iron (III) acetyl acetonato and silver (I) acetate according to the above-mentioned production method.
  • platinum-iron-silver (PtFeAg) nanoparticles with an average particle size of 2.6 nm to 3.4 nm were obtained. It was confirmed that the composition ratio of platinum iron silver nanoparticles reflects the amount of each metal compound used.
  • the inventor produced nanoparticles based on the above-mentioned production method.
  • the metal compounds include platinum (II) acetylacetonato and iron (III)
  • cobalt I) acetyl acetonatochrome
  • III cobalt
  • acetyl acetonatochrome III
  • acetyl acetonato nickel
  • II acetyl acetonato
  • mangan II) acetyla Either setnat or lead (II) acetyl acetonato was used.
  • FePtCo nanoparticles, FePtCr nanoparticles, FePtNi nanoparticles, FePtMn nanoparticles, and FePtPb nanoparticles with average particle sizes of 2.6 nm to 3.6 nm were obtained.
  • the composition ratio of these nanoparticles reflects the amount of each metal compound used.

Abstract

A composite material (39), comprising a non-magnetic substrate (41), wherein micro holes (42) are drilled in the surface of the substrate (41) and magnetic particulates (43) are disposed in the micro holes (42), whereby the particulates (43) can be surely disposed in the micro holes (42), the positions of the micro holes (42) can be regularly controlled, and the particulates (43) can be regularly disposed by the micro holes (42).

Description

明細書 複合材、 構造体およびその製造方法、 多結晶構造膜並びに微小粒子の製造方法 技術分野  TECHNICAL FIELD The present invention relates to a composite material, a structure and a method for producing the same, a polycrystalline structure film and a method for producing fine particles
本発明は、 例えばハードディスク (HD) といった磁気記録媒体に使用される ことができる複合材、 構造体およびその製造方法、 多結晶構造膜並びに微小粒子 の製造方法に関する。 背景技術  The present invention relates to a composite material, a structure and a method for producing the same, which can be used for a magnetic recording medium such as a hard disk (HD), a polycrystalline structure film, and a method for producing fine particles. Background art
例えば八一ドディスクといった磁気記録媒体の分野ではいわゆるナノホールと いった微小ホ一ルは広く知られる。 こうした微小ホールは例えば基板上でアルミ ナ膜の表面に穿たれる。 アルミナ膜の表面で微小ホールは微細な間隔で規則的に 配列される。 微小ホールには例えば C 0や C o系合金といった磁性体が充填され る。 微小ホールごとに磁性結晶粒は形作られる。 磁気記録媒体では磁気情報の記 録密度は高められることができる。  For example, in the field of magnetic recording media such as an eighteen disk, so-called nanoholes are widely known. Such minute holes are formed, for example, on the surface of the alumina film on the substrate. On the surface of the alumina film, minute holes are regularly arranged at minute intervals. The minute holes are filled with a magnetic material such as C0 or a Co-based alloy. Magnetic crystal grains are formed for each minute hole. With a magnetic recording medium, the recording density of magnetic information can be increased.
例えば日本国特開平 1 1— 2 2 4 4 2 2号公報や日本国特開 2 0 0 2 - 1 7 5 6 2 1号公報に記載されるように、 微小ホールへの磁性体の充填にあたって真空 蒸着法やスパッタリング法、 電気メツキ法は用いられる。 こうした方法では記録 磁性層の表面に余分な磁性体は堆積する。 余分な磁性体は研磨やエッチング、 ィ オンミリングに基づき除去されなければならない。 しかも、 微小ホールのァスぺ クト比が大きい場合には、 磁性体は微小ホールに均一に充填されることができな い。  For example, as described in Japanese Patent Application Laid-Open No. Hei 11-224244 and Japanese Patent Application Laid-Open No. 2002-1750561, when filling a magnetic hole into a minute hole, Vacuum evaporation, sputtering, and electric plating are used. In such a method, extra magnetic material is deposited on the surface of the recording magnetic layer. Extra magnetic material must be removed by polishing, etching, or ion milling. Moreover, when the aspect ratio of the minute holes is large, the magnetic material cannot be uniformly filled in the minute holes.
鉄白金 (F e P t ) のナノ粒子を利用した磁気記録媒体は提案される。 磁気記 録媒体の製造にあたって、 例えばォレイン酸ゃォレイルァミンに包まれたナノ粒 子は準備される。 こういったナノ粒子は例えばへキサンといった有機溶剤中で保 存される。 ナノ粒子は磁気記録媒体の基板に有機溶剤とともに塗布される。 その後、 ナノ粒子にはァニール処理が施される。 このァニール処理に基づきナ ノ粒子は結晶化する。 しかしながら、 これまでのところ、 こういったァニール処 理が実施されると大きな熱エネルギに基づきナノ粒子の融合が引き起こされてし まう。 その結果、 結晶粒は肥大化してしまう。 Magnetic recording media using iron platinum (FePt) nanoparticles have been proposed. For the production of magnetic recording media, for example, nanoparticles encapsulated in oleylamine oleate are prepared. These nanoparticles are stored in an organic solvent such as hexane. The nanoparticles are applied to a substrate of a magnetic recording medium together with an organic solvent. Thereafter, the nanoparticles are annealed. Nanoparticles crystallize based on this annealing treatment. However, so far, When the process is performed, the fusion of nanoparticles is caused by the large thermal energy. As a result, the grains become enlarged.
記録磁性層には広く磁性多結晶層が用いられる。 磁性多結晶層で結晶粒の微細 化が達成されれば、 いま以上に磁気情報の記録密度は高められることができる。 こういった結晶粒の微細化にあたっていわゆるシード層すなわち微細な結晶核は 用いられる。 シード層上で磁性材料のスパッタリングが実施されると、 結晶核か ら微細な結晶粒は成長することができる。  A magnetic polycrystalline layer is widely used for the recording magnetic layer. If the crystal grain size is reduced in the magnetic polycrystalline layer, the recording density of magnetic information can be further increased. A so-called seed layer, that is, a fine crystal nucleus, is used to make such crystal grains fine. When the magnetic material is sputtered on the seed layer, fine crystal grains can grow from the crystal nuclei.
シード層の形成にあたってスパッタリングは用いられる。 基板上ではスパッ夕 リングに基づき例えば金属材料の超薄膜が形成される。 堆積した超薄膜に加熱処 理が施されると、 超薄膜中で微細な結晶核は形成されることができる。 しかしな がら、 こういった超薄膜では、 結晶核の大きさや分散は十分に制御されることが できない。 その結果、 磁性多結晶層では結晶粒の大きさや分布にばらつきが生じ てしまう。  Sputtering is used to form the seed layer. On the substrate, an ultrathin film of, for example, a metal material is formed based on the sputtering. When the deposited ultrathin film is subjected to heat treatment, fine crystal nuclei can be formed in the ultrathin film. However, the size and dispersion of crystal nuclei in such ultrathin films cannot be adequately controlled. As a result, in the magnetic polycrystalline layer, the size and distribution of crystal grains vary.
例えば日本国特開 2000-54012号公報に開示されるように、 いわゆる ポリオ一ル法に基づくナノ金属粒子の製造方法は広く知られる。 このポリオール 法は例えばコバルト粒子の生成にあたって広く用いられる。 還元剤すなわちジォ —ルの働きで酢酸コバルトといった塩からコバルトは還元される。 しかしながら、 このポリオ一ル法ではナノ粒子同士の凝集が引き起こされやすい。 特 金属合 金のナノ粒子が製造される場合にはナノ粒子の肥大化は回避されることができな い。  For example, as disclosed in Japanese Patent Application Laid-Open No. 2000-54012, a method for producing nano metal particles based on the so-called polyol method is widely known. This polyol method is widely used, for example, in producing cobalt particles. Cobalt is reduced from salts such as cobalt acetate by the action of a reducing agent, diol. However, in this polyol method, agglomeration of nanoparticles is easily caused. When nanoparticles of special metal alloys are manufactured, enlargement of the nanoparticles cannot be avoided.
特許文献 1  Patent Document 1
日本国特開 2000— 46430号公報  Japanese Patent Publication No. 2000-46430
非特許文献 1  Non-patent document 1
Sun e t a l. 「Monod i s p e r s e F e P t N a n o p a r t i c l e s and Fe r r omagne t i c F e P t N a n o c r y s t a 1 Sup e r l a t t i c e sj, S c i enc e, Vo l 28 7, 2000年 3月, p. 1989-1992  Sun et al. "Monod isp e r se e F e P t N an o p a r t i c l e s and Fe r r omagne t i c F e P t N an o c r y st a 1 Sup e r l a t t i c e sj, Sci enc e, Vo l 287, March 2000, p. 1989
非特許文献 2  Non-patent document 2
Sun e t a 1. 「S e 1 f As s emb l i ng Magne t i c Nan oma t e r i a l s」, J. Mag. S o c. J ap an, Vo l 2 5, 2001年, p. 1434-1440 Sun eta 1. “S e 1 f As s emb ling Magnetic Magnetic Nan oma terials ”, J. Mag. Soc. Jap an, Vol 25, 2001, p. 1434-1440
非特許文献 3  Non-patent document 3
M a s u d a e t a l . 「H i gh i y o r d e r e d n ano c h anne 1— a r r ay a r ch i t e c t u r e i n anod i c a l umi na」, App l. Phy s. Le t t. 71 (19), 1997年 11 月, p. 2770 - 2772  "Mas ud ae t a l." High i y o r d e r e d n ano c h anne 1—ar r ay a r ch i t e c t u r e i an anod i c a l umi na ", Appl. Phy s. Lett t. 71 (19), November 1997, p. 2770-2772
非特許文献 4  Non-patent document 4
高橋 秀明 「アルミニウムの酸化皮膜の構造と性質 (S t r u c t u r e and P r op e r t y o f Ox i de F i lms Fo rme d o n A 1 um i num)j, 表面科学 第 9巻 第 9号, 1988年, p. 76- 82 発明の開示 .  Hideaki Takahashi "Structure and Properties of Aluminum Oxide Film (Structural and Property of Oxide Films Don a 1 uminum) j, Surface Science Vol. 9, No. 9, 1988, p. 76-82 Disclosure of the Invention ...
本発明は、 上記実状に鑑みてなされたもので、 比較的に簡単に微小ホールに均 一に磁性体を充填することができる複合材およびその製造方法を提供することを 目的とする。 本発明は、 これまで以上に微細な結晶粒を形成することができる構 造体およびその製造方法を提供することを目的とする。 本発明は、 結晶核の大き さや分散を十分に制御することができる多結晶構造膜を提供することを目的とす る。 本発明は、 比較的に簡単に微細で均一な微小粒子の製造方法を提供すること を目的とする。  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a composite material capable of relatively easily and uniformly filling a magnetic material in minute holes and a method for producing the same. An object of the present invention is to provide a structure capable of forming finer crystal grains than ever, and a method for producing the same. An object of the present invention is to provide a polycrystalline structure film capable of sufficiently controlling the size and dispersion of crystal nuclei. An object of the present invention is to provide a method for producing fine and uniform fine particles relatively easily.
上記目的を達成するために、 第 1発明によれば、 基体と、 基体の表面に穿たれ る微小ホール内に配置される微小粒子とを備えることを特徴とする複合材が提供 される。  In order to achieve the above object, according to the first invention, there is provided a composite material comprising: a base; and microparticles arranged in microholes formed in the surface of the base.
こうした複合材では、 微小粒子は微小ホール内に確実に配置されることができ る。 すなわち、 微小粒子は微小ホール内に完全に収容される。 しかも、 微小ホー ルの位置は規則的に制御されることができる。 こうした微小ホールに基づき微小 粒子は規則的に配置されることができる。  In such a composite, the microparticles can be reliably placed in the microholes. That is, the microparticles are completely contained in the microholes. Moreover, the position of the microhole can be controlled regularly. Based on these small holes, the small particles can be arranged regularly.
こういった複合材では、 基体の表面に積層されて、 微小ホール内に微小粒子を 閉じ込める被覆層が形成されてもよい。 こういった被覆層によれば微小粒子は微 小ホール内に完全に収容される。 基体の表面に微小粒子は存在しない。 In such composites, the microparticles are deposited in the microholes by being laminated on the surface of the substrate. A confining coating layer may be formed. According to such a coating layer, the fine particles are completely contained in the fine holes. There are no microparticles on the surface of the substrate.
以上のような複合材では、 基体および微小粒子のうち一方は磁性体から構成さ れ、 他方は非磁性体から構成されてもよい。 その一方で、 基体および微小粒子の うち一方は導電体から構成され、 他方は絶縁体から構成されてもよい。  In the composite material as described above, one of the substrate and the fine particles may be made of a magnetic material, and the other may be made of a non-magnetic material. On the other hand, one of the substrate and the fine particles may be made of a conductor, and the other may be made of an insulator.
こうした複合材では、 微小粒子は金属元素から構成されればよい。 微小粒子は 結晶粒から構成されてもよい。 微小粒子では、 基体の表面に直交する垂直方向に 磁化容易軸が確立されてもよい。 微小ホールの直径は 4 nm〜 5 0 nmの範囲で 設定されればよく、 深さは 2〜1 0のァスぺクト比で設定されればよい。  In such a composite, the fine particles may be composed of a metal element. The fine particles may be composed of crystal grains. For microparticles, an easy axis of magnetization may be established in a perpendicular direction perpendicular to the surface of the substrate. The diameter of the minute holes may be set in a range of 4 nm to 50 nm, and the depth may be set in an aspect ratio of 2 to 10 nm.
第 2発明によれば、 表面に穿たれる微小ホールを有する基体を用意する工程と、 基体の表面に、 特定の溶媒中に微小粒子を含む液体を塗布する工程と、 微小ホー ルから基体の表面に溢れる微小粒子を拭い去る工程とを備えることを特徴とする 複合材の製造方法が提供される。  According to the second invention, a step of preparing a substrate having fine holes drilled on the surface, a step of applying a liquid containing fine particles in a specific solvent to the surface of the substrate, Wiping off microparticles overflowing on the surface.
以上のような製造方法によれば、 基体の表面に、 特定の溶媒中に微小粒子を含 む液体が塗布されることから、 微小粒子は比較的に簡単に微小ホール内に流れ込 むことができる。 微小粒子は微小ホ一ル内に均一に充填されることができる。 こ うした微小粒子を含む液体の塗布にあたってスピンコ一ト法またはディップ法が 実施されればよい。  According to the manufacturing method as described above, since a liquid containing fine particles in a specific solvent is applied to the surface of the substrate, the fine particles can flow into the minute holes relatively easily. it can. The microparticles can be uniformly filled in the microholes. In applying the liquid containing such fine particles, a spin coating method or a dipping method may be performed.
以上のような複合材の製造にあたって、 基体および微小粒子のうち一方は磁性 体から構成され、 他方は非磁性体から構成されてもよい。 微小ホールの直径は 4 nm〜5 0 nm程度に設定されればよく、 深さは 2〜1 0のァスぺクト比で設定 されればよい。  In producing the above-described composite material, one of the substrate and the fine particles may be made of a magnetic material, and the other may be made of a non-magnetic material. The diameter of the minute holes may be set to about 4 nm to 50 nm, and the depth may be set to an aspect ratio of 2 to 10 nm.
なお、 以上のような複合材は、 例えばハードディスク (HD) といった垂直磁 気記録媒体に利用されてもよく、 その他の磁気記録媒体に利用されてもよい。 第 3発明によれば、 微小粒子の集合体と、 微小粒子同士の間に存在する炭素原 子とを備え、 微小粒子を構成する原子の原子数および炭素原子の原子数の総計に 対して炭素原子単独の原子数は 4 5原子%〜9 6原子%の範囲に設定されること を特徴とする構造体が提供される。.  The above-described composite material may be used for a perpendicular magnetic recording medium such as a hard disk (HD), or may be used for other magnetic recording media. According to the third invention, an aggregate of fine particles and a carbon atom existing between the fine particles are provided, and the carbon number is smaller than the total number of atoms constituting the fine particles and the total number of carbon atoms. A structure is provided, wherein the number of atoms alone is set in the range of 45 to 96 atomic%. .
こうした微小粒子の直径は 1 nm〜 3 0 nmの範囲で設定されればよい。 微小 粒子は、 F e、 C oおよび N iの少なくともいずれかを含む磁性体で構成されれ ばよい。 また、 微小粒子には結晶粒が含まれればよい。 The diameter of such fine particles may be set in the range of 1 nm to 30 nm. Minute The particles may be made of a magnetic material containing at least one of Fe, Co, and Ni. The fine particles may include crystal grains.
第 4発明によれば、 対象物の表面に、 有機化合物で包まれる微小金属粒子を含 む有機溶剤を塗布する工程と、 有機溶剤の乾燥後に、 真空環境下で微小金属粒子 にァニール処理を施す工程とを備え、 微小金属粒子を構成する原子の原子数と有 機化合物中の炭素原子の原子数との総計に対して有機化合物中の炭素原子の原子 数は 4 5原子%〜9 6原子%の範囲に設定されることを特徴とする構造体の製造 方法が提供される。  According to the fourth invention, a step of applying an organic solvent containing fine metal particles wrapped with the organic compound to the surface of the object, and subjecting the fine metal particles to an annealing treatment under a vacuum environment after drying the organic solvent The number of carbon atoms in the organic compound is 45 to 96 atomic% with respect to the total number of atoms constituting the fine metal particles and the number of carbon atoms in the organic compound. % Is provided in the range of%.
かかる製造方法によれば、 比較的に多量の有機化合物の働きで、 ァニール処理 の実施にも拘わらず微小金属粒子の凝集は回避されることができる。 微小金属粒 子は微細な結晶粒のまま維持される。  According to such a production method, aggregation of the fine metal particles can be avoided by the action of the relatively large amount of the organic compound despite the execution of the annealing treatment. The fine metal particles are maintained as fine crystal grains.
こういった製造方法は、 ァニール処理の実施に先立って、 不活性ガス雰囲気下 で有機化合物に加熱処理を施す工程をさらに備えてもよい。 こうした製造方法に よれば、 有機安定剤の増量にも拘わらず、 微小金属粒子および有機安定剤で構成 される層の表面には平坦面が確立されることができる。  Such a manufacturing method may further include a step of subjecting the organic compound to a heat treatment under an inert gas atmosphere prior to performing the annealing treatment. According to such a production method, a flat surface can be established on the surface of the layer composed of the fine metal particles and the organic stabilizer, despite the increase in the amount of the organic stabilizer.
第 5発明によれば、 基層と、 基層の表面に配置される微小粒子と、 微小粒子に 基づき成長する結晶粒を含む結晶層とを備えることを特徴とする多結晶構造膜が 提供される。  According to the fifth invention, there is provided a polycrystalline structure film comprising a base layer, fine particles arranged on the surface of the base layer, and a crystal layer including crystal grains that grow based on the fine particles.
こういった多結晶構造膜によれば、 結晶層の結晶粒は微小粒子に基づき成長す る。 微小粒子の大きさや分散は十分に制御されることから、 結晶層では結晶粒の 大きさや分布は確実に制御されることができる。 ' こうした多結晶構造膜では、 微小粒子には金属元素が含まれればよい。 微小粒 子の直径は 1 nm〜3 0 nmの範囲で設定されればよい。 微小粒子は、 基層の表 面に途切れなく広がる連続層を形成すればよい。  According to such a polycrystalline structure film, the crystal grains of the crystal layer grow based on the fine particles. Since the size and dispersion of the fine particles are sufficiently controlled, the size and distribution of the crystal grains in the crystal layer can be reliably controlled. '' In such a polycrystalline film, the fine particles only need to contain a metal element. The diameter of the fine particles may be set in the range of 1 nm to 30 nm. The fine particles may form a continuous layer that extends continuously on the surface of the base layer.
以上のような多結晶構造膜は磁気記録媒体に用いられることができる。 磁気記 録媒体では、 微小粒子に基づき成長する結晶粒で構成される下地多結晶層と、 下 地多結晶層の個々の結晶粒から成長する結晶粒で構成される磁性多結晶層とが積 層形成されればよい。  Such a polycrystalline structure film can be used for a magnetic recording medium. In a magnetic recording medium, an underlying polycrystalline layer composed of crystal grains that grow based on fine particles and a magnetic polycrystalline layer composed of crystal grains that grow from individual crystal grains of the underlying polycrystalline layer are stacked. What is necessary is just to form a layer.
同様に、 以上のような多結晶構造膜は、 レ ^わゆる垂直磁気記録媒体に用いられ ることができる。 このとき、 垂直磁気記録媒体では、 微小粒子に基づき成長する 結晶粒で構成される磁性多結晶層が積層形成されればよく、 非磁性層で磁性多糸 i 晶層から隔てられる軟磁性の裏打ち層がさらに形成されればよい。 Similarly, such a polycrystalline structure film is used for a perpendicular magnetic recording medium. Can be At this time, in the perpendicular magnetic recording medium, a magnetic polycrystalline layer composed of crystal grains that grow based on fine particles only needs to be laminated and formed. What is necessary is just to form a layer further.
こういった磁気記録媒体では、 下地多結晶層の結晶粒は微小粒子に基づき成長 する。 微小粒子の大きさや分散は十分に制御されることから、 下地多結晶層では 結晶粒の大きさや分布は確実に制御されることができる。 磁性多結晶層は、 下地 多結晶層の個々の結晶粒から成長する結晶粒で構成されることから、 結晶粒の大 きさや分布は確実に制御されることができる。 磁気記録媒体では磁気情報の記録 密度はこれまで以上に高められることができる。  In such a magnetic recording medium, the crystal grains of the underlying polycrystalline layer grow based on fine particles. Since the size and dispersion of the fine particles are sufficiently controlled, the size and distribution of the crystal grains can be reliably controlled in the underlying polycrystalline layer. Since the magnetic polycrystalline layer is composed of crystal grains that grow from individual crystal grains of the underlying polycrystalline layer, the size and distribution of the crystal grains can be reliably controlled. With a magnetic recording medium, the recording density of magnetic information can be increased more than ever.
微小粒子には、 前述と同様に、 金属元素が含まれればよい。 しかも、 微小粒子 の直径は 1 nm〜3 0 nmの範囲で設定されればよい。  The fine particles may contain a metal element as described above. In addition, the diameter of the fine particles may be set in the range of 1 nm to 30 nm.
第 6発明によれば、 有機溶媒中に、 有機溶媒に対して難溶を示す還元剤、 金属 化合物および有機安定剤を含む溶液を生成する工程と、 所定の反応温度下で溶液 を撹拌する工程とを備えることを特徴とする微小粒子の製造方法が提供される。 こういった製造方法によれば、 還元剤は有機溶媒に溶け難いことから、 還元剤 と有機溶媒とは相分離されることができる。 溶液の極性は低く保持される結果、 微小粒子の凝集は十分に阻止されることができる。 比較的に簡単に微細かつ均一 な微小粒子は形成されることができる。  According to the sixth invention, a step of producing a solution containing a reducing agent, a metal compound, and an organic stabilizer that is hardly soluble in the organic solvent in the organic solvent, and a step of stirring the solution at a predetermined reaction temperature And a method for producing microparticles, comprising: According to such a production method, since the reducing agent is hardly soluble in the organic solvent, the reducing agent and the organic solvent can be phase-separated. As a result of keeping the polarity of the solution low, aggregation of the fine particles can be sufficiently prevented. Fine and uniform fine particles can be formed relatively easily.
こうした微小粒子の製造方法では、 金属化合物は、 ァセチルァセトナト塩、 炭 素数 1〜2 0の有機酸の塩、 臭化物およびヨウ化物の少なくともいずれかから選 択されればよい。 しかも、 生成される溶液には 2種類以上の前記金属化合物が含 まれてもよい。  In such a method for producing fine particles, the metal compound may be selected from at least one of acetyl acetonate salt, a salt of an organic acid having 1 to 20 carbon atoms, bromide, and iodide. Moreover, the generated solution may contain two or more kinds of the metal compounds.
有機溶媒は炭素数 6〜 2 0の非プロ卜ン性有機溶媒で構成されればよい。 こう いった有機溶媒は、 炭化水素、 エーテルおよびエステルのいずれかから選択され ればよい。 還元剤には炭素数 2〜6の 1,2-ジオールが用いられればよい。  The organic solvent may be a nonprotonic organic solvent having 6 to 20 carbon atoms. These organic solvents may be selected from hydrocarbons, ethers and esters. A 1,2-diol having 2 to 6 carbon atoms may be used as the reducing agent.
有機安定剤はカルボン酸 R— C OOHを含めばよい。 このとき、 カルボン酸中 の Rは C 1 2 H 2 3、 (:1 7113 3ぉょび( 2 1114 1のぃずれかから選択されればょぃ。 有機安定剤はァミン R— NH2を含んでもよい。 このとき、 ァミン中の Rは C 1 3 H 2 5、 C 1 8H 3 5および C 2 2H4 3のいずれかから選択されればよい。 以上のような製造方法では溶液の反応温度は 1 0 0 t:〜 3 0 0 の範囲で設定 されればよい。 図面の簡単な説明 The organic stabilizer may include a carboxylic acid R—C OOH. At this time, the R in the carboxylic acid C 1 2 H 2 3, ( :. 1 7 11 3 3 Oyobi (2 1 11 4 1 if it is selected from or Re Izu Yoi organic stabilizer Amin R -. may include NH 2 this time, R in Amin is may be selected from any of C 1 3 H 2 5, C 1 8 H 3 5 and C 2 2 H 4 3. In the above manufacturing method, the reaction temperature of the solution may be set in the range of 100 t: to 300. BRIEF DESCRIPTION OF THE FIGURES
図 1は、 磁気記録媒体駆動装置の一具体例すなわちハードディスク駆動装置 (HD D) の内部構造を概略的に示す平面図である。  FIG. 1 is a plan view schematically showing a specific example of a magnetic recording medium drive, that is, an internal structure of a hard disk drive (HDD).
図 2は、 本発明の第 1実施形態に係る磁気ディスクの構造を詳細に示す拡大垂 直断面図である。  FIG. 2 is an enlarged vertical sectional view showing in detail the structure of the magnetic disk according to the first embodiment of the present invention.
図 3は、 アルミニゥム膜の表面に窪みを形成する工程を概略的に示す基板の拡 大部分断面図である。  FIG. 3 is an enlarged partial cross-sectional view of the substrate schematically showing a step of forming a depression on the surface of the aluminum film.
図 4は、 基質層の表面にナノホールを形成する工程を概略的に示す基板の拡大 部分断面図である。  FIG. 4 is an enlarged partial cross-sectional view of the substrate schematically showing a step of forming nanoholes on the surface of the substrate layer.
' 図 5は、 基質層の表面にナノ粒子を含む液体を塗布する工程を概略的に示す基 板の拡大部分断面図である。  FIG. 5 is an enlarged partial cross-sectional view of the substrate schematically showing a step of applying a liquid containing nanoparticles to the surface of the substrate layer.
図 6は、 基質層の表面に残存するナノ粒子を拭い去る工程を概略的に示す基板 の拡大部分断面図である。  FIG. 6 is an enlarged partial cross-sectional view of the substrate schematically showing a step of wiping off nanoparticles remaining on the surface of the substrate layer.
図 7は、 本発明の第 2実施形態に係る磁気ディスクの構造を詳細に示す拡大垂 直断面図である。  FIG. 7 is an enlarged vertical sectional view showing in detail the structure of the magnetic disk according to the second embodiment of the present invention.
図 8は、 液層に加熱処理を施す工程を概略的に示す基板の拡大垂直断面図であ る。  FIG. 8 is an enlarged vertical sectional view of a substrate schematically showing a step of performing a heat treatment on the liquid layer.
図 9は、 液層に加熱処理を施した後の構造を概略的に示す基板の拡大垂直断面 図である。  FIG. 9 is an enlarged vertical sectional view of the substrate schematically showing the structure after the liquid layer has been subjected to the heat treatment.
図 1 0は、 一具体例に係る磁気ディスクの A F M (原子間力顕微鏡) 像の断面 図である。  FIG. 10 is a cross-sectional view of an AFM (atomic force microscope) image of a magnetic disk according to a specific example.
図 1 1は、 一比較例に係る磁気ディスクの A F M像の断面図である。  FIG. 11 is a cross-sectional view of an AFM image of a magnetic disk according to a comparative example.
図 1 2は、 本発明の第 3実施形態に係る磁気ディスクの構造を詳細に示す拡大 垂直断面図である。  FIG. 12 is an enlarged vertical sectional view showing in detail the structure of the magnetic disk according to the third embodiment of the present invention.
図 1 3は、 第 3実施形態の変形例に係る磁気ディスクの構造を詳細に示す拡大 垂直断面図である。 図 1 4は、 スピンコ一夕の内部構造を概略的に示す側面図である。 FIG. 13 is an enlarged vertical sectional view showing in detail the structure of a magnetic disk according to a modification of the third embodiment. FIG. 14 is a side view schematically showing the internal structure of the spinco.
図 1 5は、 金属化合物の使用量とナノ粒子の組成比との関係を示す表である。 発明を実施するための最良の形態  FIG. 15 is a table showing the relationship between the amount of the metal compound used and the composition ratio of the nanoparticles. BEST MODE FOR CARRYING OUT THE INVENTION
以下、 添付図面を参照しつつ本発明の実施形態を説明する。  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
図 1は磁気記録媒体駆動装置の一具体例すなわちハードディスク駆動装置 (H D D) 1 1の内部構造を概略的に示す。 この HDD 1 1は、 例えば平たい直方体 の内部空間を区画する箱形の筐体本体 1 2を備える。 収容空間には、 磁気記録媒 体としての 1枚以上の磁気ディスク 1 3が収容される。 磁気ディスク 1 3はスピ ンドルモータ 1 4の回転軸に装着される。 スピンドルモー夕 1 4は例えば 7 2 0 0 r p mや 1 0 0 0 0 r p mといった高速度で磁気ディスク 1 3を回転させるこ とができる。 筐体本体 1 2には、 筐体本体 1 2との間で収容空間を密閉する蓋体 すなわちカバー (図示されず) が結合される。  FIG. 1 schematically shows a specific example of a magnetic recording medium drive, that is, an internal structure of a hard disk drive (HDD) 11. The HDD 11 includes, for example, a box-shaped housing main body 12 that partitions an internal space of a flat rectangular parallelepiped. One or more magnetic disks 13 as a magnetic recording medium are accommodated in the accommodation space. The magnetic disk 13 is mounted on a rotating shaft of a spindle motor 14. The spindle motor 14 can rotate the magnetic disk 13 at a high speed such as, for example, 720 rpm or 1000 rpm. The housing body 12 is connected with a lid (not shown) for sealing the accommodation space between the housing body 12 and the housing body 12.
収容空間では、 垂直方向に延びる支軸 1 5にへッドアクチユエ一夕 1 6が装着 される。 ヘッドァクチユエ一夕 1 6は、 支軸 1 5から水平方向に延びる剛体のァ クチユエ一夕アーム 1 7と、 このァクチユエ一夕アーム 1 7の先端に取り付けら れてァクチユエ一夕ァ一ム 1 7から前方に延びる弾性サスペンション 1 8とを備 える。 周知の通り、 弾性サスペンション 1 8の先端では、 いわゆるジンバルばね (図示されず) の働きで浮上ヘッドスライダ 1 9は片持ち支持される。 浮上へッ ドスライダ 1 9には、 磁気ディスク 1 3の表面に向かって弾性サスペンション 1 8から押し付け力が作用する。 磁気ディスク 1 3が回転すると、 磁気ディスク 1 3の表面で生成される気流の働きで浮上へッドスライダ 1 9には浮力が作用する。 弾性サスペンション 1 8の押し付け力と浮力とのバランスで磁気ディスク 1 3の 回転中に比較的に高い剛性で浮上へッドスライダ 1 9は浮上し続けることができ る。  In the containment space, a head shaft 16 extending vertically is fitted with a head actuator 16. The head actuator 16 is composed of a rigid actuator arm 17 extending horizontally from the support shaft 15 and an actuator 17 attached to the tip of the actuator arm 17. An elastic suspension 18 extending forward is provided. As is well known, the flying head slider 19 is cantilevered at the tip of the elastic suspension 18 by a so-called gimbal spring (not shown). A pressing force is applied to the flying head slider 19 from the elastic suspension 18 toward the surface of the magnetic disk 13. When the magnetic disk 13 rotates, buoyancy acts on the flying head slider 19 by the action of the airflow generated on the surface of the magnetic disk 13. Due to the balance between the pressing force of the elastic suspension 18 and the buoyancy, the flying head slider 19 can keep flying with relatively high rigidity during the rotation of the magnetic disk 13.
浮上ヘッドスライダ 1 9には、 周知の通りに、 磁気ヘッドすなわち電磁変換素 子 (図示されず) が搭載される。 この電磁変換素子は、 例えば、 スピンバルブ膜 やトンネル接合膜の抵抗変ィ匕を利用して磁気ディスク 1 3から情報を読み出す巨 大磁気抵抗効果 (GMR) 素子やトンネル接合磁気抵抗効果 (TMR) 素子とい つた読み出し素子と、 薄膜コイルパターンで生成される磁界を利用して磁気ディ スク 1 3に情報を書き込む単磁極へッドゃ誘導書き込みへッドといった書き込み 素子 (図示されず) とで構成されればよい。 As is well known, a magnetic head, that is, an electromagnetic transducer (not shown) is mounted on the flying head slider 19. This electromagnetic transducer is, for example, a giant magnetoresistive (GMR) element or a tunnel junction magnetoresistive (TMR) element that reads information from a magnetic disk 13 by using the resistance change of a spin valve film or a tunnel junction film. Element A read element and a write element (not shown) such as a single magnetic pole head and an inductive write head that write information on the magnetic disk 13 using the magnetic field generated by the thin film coil pattern. Just fine.
浮上へッドスライダ 1 9の浮上中に、 ヘッドァクチユエ一夕 1 6が支軸 1 5回 りで回転すると、 浮上へッドスライダ 1 9は半径方向に磁気ディスク 1 3の表面 を横切ることができる。 こうした移動に基づき浮上ヘッドスライダ 1 9上の電磁 変換素子は磁気ディスク 1 3上の所望の記録トラックに位置決めされる。 へッド ァクチユエ一夕 1 6の回転は例えばボイスコイルモー夕 (V C M) といった駆動 源 2 1の働きを通じて実現されればよい。 周知の通り、 複数枚の磁気ディスク 1 3が筐体本体 1 2内に組み込まれる楊合には、 隣接する磁気ディスク 1 3同士の 間で 2本のァクチユエ一夕アーム 1 7すなわち 2つの浮上ヘッドスライダ 1 9が 配置される。  If the head actuator 16 rotates around the support shaft 15 times while the flying head slider 19 is flying, the flying head slider 19 can cross the surface of the magnetic disk 13 in the radial direction. Based on such movement, the electromagnetic transducer on the flying head slider 19 is positioned at a desired recording track on the magnetic disk 13. The rotation of the head actuator 16 may be realized through the operation of the drive source 21 such as a voice coil motor (VCM). As is well known, when a plurality of magnetic disks 13 are incorporated in the housing body 12, two actuator arms 17 between adjacent magnetic disks 13, that is, two floating heads Slider 19 is arranged.
図 2は本発明の第 1実施形態に係る磁気ディスク 1 3の断面構造を詳細に示す。 この磁気ディスク 1 3はいわゆる垂直磁気記録媒体として構成される。 磁気ディ スク 1 3は、 支持体としての基板 3 1と、 この基板 3 1の表裏面に広がる多層構 造膜 3 2とを備える。 基板 3 1は、 例えば、 ディスク形の S i本体 3 3と、 S i 本体 3 3の表裏面に広がる非晶質の S i 02膜 3 4とで構成されればよい。 ただ し、 基板 3 1にはガラス基板やアルミニウム基板、 セラミック基板が用いられて もよい。 多層構造膜 3 2に磁気情報は記録される。 多層構造膜 3 2の表面は、 例 えばダイヤモンドライク力一ボン (D L C) 膜といった保護膜 3 5や、 例えばパ —フルォロポリエーテル (P F P E) 膜といった潤滑膜 3 6で被覆される。 FIG. 2 shows a cross-sectional structure of the magnetic disk 13 according to the first embodiment of the present invention in detail. This magnetic disk 13 is configured as a so-called perpendicular magnetic recording medium. The magnetic disk 13 includes a substrate 31 as a support, and a multilayer structure film 32 extending on the front and back surfaces of the substrate 31. Substrate 3 1 are, for example, the S i body 3 3 of the disc-shaped, may be made by the S i body 3 amorphous extending 3 on the front and back surfaces S i 0 2 film 3 4. However, a glass substrate, an aluminum substrate, or a ceramic substrate may be used as the substrate 31. Magnetic information is recorded on the multilayer structure film 32. The surface of the multilayer structure film 32 is covered with a protective film 35 such as a diamond-like carbon (DLC) film and a lubricating film 36 such as a perfluoropolyether (PFPE) film.
多層構造膜 3 2は、 基板 3 1の表面に広がる裏打ち層 3 7を備える。 裏打ち層 3 7は例えば F e T a C膜や N i F e膜といった軟磁性体から構成されればよい。 ここでは、 裏打ち層 3 7に例えば膜厚 2 0 O nm程度の F e T a C膜が用いられ ればよい。 裏打ち層 3 7では基板 3 1の表面に平行に規定される面内方向に磁ィ匕 容易軸は確立される。  The multilayer structure film 32 includes a backing layer 37 extending on the surface of the substrate 31. The backing layer 37 may be made of a soft magnetic material such as a FeTaC film or a NiFe film. Here, a FeTaC film having a thickness of about 20 O nm, for example, may be used for the backing layer 37. In the backing layer 37, an easy axis is established in an in-plane direction defined in parallel with the surface of the substrate 31.
裏打ち層 3 7の表面には中間層 3 8が広がる。 中間層 3 8は例えばアルミニゥ ム膜といった非磁性体から構成されればよい。 中間層 3 8の表面には複合材すな わち記録磁性層 3 9が広がる。 記録磁性層 3 9は、 中間層 3 8の表面に広がる基 体すなわち基質層 4 1を備える。 基質層 4 1には例えばアルミナ (A 1 23) といつた非磁性体が用いられればよい。 The intermediate layer 38 extends on the surface of the backing layer 37. The intermediate layer 38 may be made of a nonmagnetic material such as an aluminum film. The composite material, that is, the recording magnetic layer 39 is spread on the surface of the intermediate layer 38. The recording magnetic layer 39 is formed by a substrate extending on the surface of the intermediate layer 38. The body or substrate layer 41 is provided. The substrate layer 4 1 may be employed such as alumina (A 1 23) and when was the non-magnetic material.
基質層 4 1の表面には微小ホールすなわちナノホール 4 2が穿たれる。 ナノホ —ル 4 2は基質層 4 1の表面に規則的に配置される。 ナノホール 4 2は、 例えば、 基板 3 1の周方向に等間隔で並行する列に沿って配置されればよい。 各列では、 列同士の間隔と等しい間隔でナノホール 4 2は配列されればよい。 ナノホール 4 2同士の間隔は例えば 4 n m〜 3 0 nm程度に設定されればよい。 ナノホール 4 2の直径は 4 nm〜 5 0 nm程度に設定されればよい。 ナノホール 4 2の深さは 2〜1 0のァスぺクト比に基づき設定されればよい。 ァスぺクト比はナノホール 4 2の直径に対する深さの比率を示す。  Micro holes, ie, nano holes 42, are formed in the surface of the substrate layer 41. The nanoholes 42 are regularly arranged on the surface of the substrate layer 41. The nanoholes 42 may be arranged, for example, along rows that are parallel at equal intervals in the circumferential direction of the substrate 31. In each row, the nanoholes 42 may be arranged at an interval equal to the interval between the rows. The distance between the nanoholes 42 may be set to, for example, about 4 nm to 30 nm. The diameter of the nanohole 42 may be set to about 4 nm to 50 nm. The depth of the nanoholes 42 may be set based on an aspect ratio of 2 to 10. The aspect ratio indicates the ratio of the depth to the diameter of the nanohole 42.
ナノホール 4 2内に微小粒子すなわちナノ粒子 4 3が配置される。 ナノ粒子 4 3は金属元素を含む。 ナノ粒子 4 3には例えば F e、 C oおよび N iといった磁 性体のいずれかが少なくとも含まれればよい。 ナノ粒子 4 3には例えば C rや P t、 P dといった材料がさらに含まれてもよい。 ここでは、 ナノ粒子 4 3には例 えば磁性の F e P t合金が用いられればよい。  Microparticles, that is, nanoparticles 43 are arranged in the nanoholes 42. The nanoparticles 43 contain a metal element. The nanoparticles 43 need only include at least one of magnetic materials such as Fe, Co, and Ni. The nanoparticles 43 may further include materials such as Cr, Pt, and Pd. Here, for example, a magnetic FePt alloy may be used for the nanoparticles 43.
こういったナノ粒子 4 3は結晶粒から構成される。 個々の結晶粒では基質層 4 1の表面に直交する垂直方向に磁ィ匕容易軸が確立される。 結晶粒の表面は炭素原 子 (図示されず) に包まれる。 炭素原子によれば、 個々の結晶粒はナノホール 4 2内で単独に存在することができる。 その一方で、 結晶粒同士はナノホール 4 2 内で融合してもよい。 融合した結晶粒の表面は炭素原子に包まれる。  These nanoparticles 43 are composed of crystal grains. In each of the crystal grains, an easy axis is established in a vertical direction perpendicular to the surface of the substrate layer 41. The surface of the crystal grain is wrapped in a carbon atom (not shown). According to carbon atoms, individual grains can exist alone within nanoholes 42. On the other hand, the crystal grains may fuse within the nanohole 42. The surface of the fused grains is enveloped by carbon atoms.
ナノ粒子 4 3の粒径は、 前述のナノホール 4 2の直径よりも常に小さな粒径に 設定される。 ナノ粒子 4 3の粒径は、 例えばナノホール 4 2の直径に対して 5分 の 2〜 2分の 1程度の比率に基づき設定されればよい。 ナノ粒子 4 3の平均粒径 Dに対する粒径分布の標準偏差 σの比率すなわち粒径分散 σ ZDは 1 0 %以下に 設定されればよい。 ナノホール 4 2内でナノ粒子 4 3同士の間隔は 0. 2 ηπ!〜 5 . 0 nm程度に設定されればよい。  The particle size of the nanoparticles 43 is always set to a smaller particle size than the diameter of the nanoholes 42 described above. The particle size of the nanoparticles 43 may be set based on, for example, a ratio of about one-fifth to one-half of the diameter of the nanoholes 42. The ratio of the standard deviation σ of the particle size distribution to the average particle size D of the nanoparticles 43, that is, the particle size variance σ ZD may be set to 10% or less. The spacing between nanoparticles 43 within nanohole 42 is 0.2 ηπ! It may be set to about 5.0 nm.
図 2から明らかなように、 基質層 4 1の表面に保護膜 3 5は積層形成される。 保護膜 3 5によれば、 ナノホール 4 2内にナノ粒子 4 3は閉じ込められる。 すな わち、 保護膜 3 5は被覆層として機能する。 保護膜 3 5によればナノ粒子 4 3は ナノホール 4 2内に完全に収容される。 ナノ粒子 4 3は、 ナノホール 4 2内にの み配置され基質層 4 1の表面には配置されない。 As is apparent from FIG. 2, the protective film 35 is formed on the surface of the substrate layer 41. According to the protective film 35, the nanoparticles 43 are confined in the nanoholes 42. That is, the protective film 35 functions as a coating layer. According to the protective film 35, the nanoparticles 43 are It is completely contained in the nanohole 42. The nanoparticles 43 are arranged only in the nanoholes 42 and are not arranged on the surface of the substrate layer 41.
こういった磁気ディスク 1 3ではナノ粒子 4 3に基づき記録磁性層 3 9の磁ィ匕 方向は特定されることができる。 ナノホール 4 2に基づきナノ粒子 4 3は規則的 に配置されることができる。 個々の磁化領域ごとに明確に輪郭線は描き出される ことができる。 いわゆる遷移ノイズは抑制される。 こういった磁気ディスク 1 3 では、 確実に磁気情報の記録密度は高められることができる。  In such a magnetic disk 13, the direction of magnetization of the recording magnetic layer 39 can be specified based on the nanoparticles 43. The nanoparticles 43 can be regularly arranged based on the nanoholes 42. The outline can be clearly drawn for each individual magnetization region. So-called transition noise is suppressed. In such a magnetic disk 13, the recording density of magnetic information can be reliably increased.
次に、 磁気ディスク 1 3の製造方法を詳述する。 まず、 ディスク形の基板 3 1 が用意される。 基板 3 1の表面には裏打ち層 3 7やアルミニウム層が順番に形成 される。 裏打ち層 3 7やアルミニウム層の形成にあたって例えばスパッタリング 法や真空蒸着法が用いられればよい。 続いてアルミニウム層に基づきナノホール 4 2が穿たれる。 ナノホ一ル 4 2の形成の過程でアルミニウム層の表面は酸化し ていく。 こうしてアルミニウム層から中間層 3 8および基質層 4 1が形成される。 ナノホール 4 2の形成方法の詳細は後述される。  Next, a method of manufacturing the magnetic disk 13 will be described in detail. First, a disk-shaped substrate 31 is prepared. A backing layer 37 and an aluminum layer are sequentially formed on the surface of the substrate 31. In forming the backing layer 37 and the aluminum layer, for example, a sputtering method or a vacuum evaporation method may be used. Subsequently, nanoholes 42 are formed based on the aluminum layer. In the process of forming nanoholes 42, the surface of the aluminum layer is oxidized. Thus, the intermediate layer 38 and the substrate layer 41 are formed from the aluminum layer. Details of the method for forming the nanoholes 42 will be described later.
その後、 個々のナノホール 4 2にはナノ粒子 4 3が充填される。 ナノ粒子 4 3 には加熱処理が施される。 加熱処理にあたって基板 3 1はァニールチャンバ内に 設置される。 チャンバ内では 3 X 1 0 _ 5 [ P a ] 以下の真空環境が確立される。 チャンバ内の温度は 2 0 0 °C〜9 0 0 °Cの範囲で設定されればよい。 例えば 3 0 分間にわたって 8 0 0 °Cの温度が維持されればよい。 チャンバ内の温度は室温か ら 8 0 0。Cまで 1 0分間で上昇すればよい。 加熱中、 ナノ粒子 4 3には所定の磁 場が適用される。 磁場の大きさは例えば 0 . 1〜: L 0 . 0 [T] の範囲で設定さ れればよい。 こうして個々のナノ粒子 4 3で磁化容易軸の方向は制御される。 そ の後、 基板 3 1は室温まで冷却される。 Thereafter, the individual nanoholes 42 are filled with nanoparticles 43. The nanoparticles 43 are subjected to a heat treatment. In the heat treatment, the substrate 31 is set in an annealing chamber. Within the chamber 3 X 1 0 _ 5 [P a] following the vacuum environment is established. The temperature in the chamber may be set in the range of 200 ° C. to 900 ° C. For example, a temperature of 800 ° C. may be maintained for 30 minutes. The temperature in the chamber is 800 from room temperature. It only has to rise to C in 10 minutes. During heating, a predetermined magnetic field is applied to the nanoparticles 43. The magnitude of the magnetic field may be set, for example, in the range of 0.1 to: L 0.0 [T]. Thus, the direction of the axis of easy magnetization is controlled by each of the nanoparticles 43. Thereafter, the substrate 31 is cooled to room temperature.
ナノ粒子 4 3の充填後、 基質層 4 1の表面には保護膜 3 5や潤滑膜 3 6が形成 される。 保護膜 3 5の形成には例えばスパッタリング法が用いられればよい。 潤 滑膜 3 6は例えばディップ法に基づき塗布されればよい。  After the filling of the nanoparticles 43, a protective film 35 and a lubricating film 36 are formed on the surface of the substrate layer 41. The protective film 35 may be formed by, for example, a sputtering method. The lubricating film 36 may be applied based on, for example, a dipping method.
次に、 ナノホール 4 3の形成方法を詳述する。 図 3に示されるように、 基板 3 1上で、 アルミニウム膜 4 4の表面に鎢型 4 5が押し付けられる。 鐃型 4 5の表 面には所定の間隔で突起 4 6が形成される。 突起 4 6の押し付けに基づきアルミ 二ゥム膜 4 5の表面に微細な窪み 4 7が形成される。 Next, a method for forming the nanoholes 43 will be described in detail. As shown in FIG. 3, a rectangular pattern 45 is pressed on the surface of the aluminum film 44 on the substrate 31. Protrusions 46 are formed at predetermined intervals on the surface of the cymbal shape 45. Aluminum based on pressing of protrusions 4 and 6 Fine depressions 47 are formed on the surface of the film 45.
続いて、 アルミニウム膜 4 4に陽極酸化が実施される。 アルミニウム膜 4 4は 水溶液に浸される。 水溶液には例えば 2 5 °Cの篠酸水溶液 0 . 5 [M] が使用さ れる。 印加電圧は例えば 4 0 [V] に設定される。 陽極酸ィ匕の反応に基づき、 ァ ルミ二ゥム膜 4 4は表面から酸ィ匕していく。 前述の窪み 4 7からナノホール 4 2 が成長していく。 こうして、 図 4に示されるように、 基質層 4 1の表面にナノホ —ル 4 2が形成される。 その後、 基質層 4 1は燐酸溶液中に浸される。 燐酸溶液 との反応に基づきナノホール 4 2の内周面はエッチングされる。 こうしてナノホ ール 4 2の直径は例えば 1 0 nm程度に設定される。 同様に、 ナノホール 4 2の 深さは 3 O nm程度に設定される。 なお、 陽極酸化されない部分はアルミニウム の中間層 3 8を形成する。  Subsequently, anodization is performed on the aluminum film 44. The aluminum film 44 is immersed in an aqueous solution. For example, 0.5 [M] of a shinic acid aqueous solution at 25 ° C is used as the aqueous solution. The applied voltage is set to, for example, 40 [V]. The aluminum film 44 is oxidized from the surface based on the anodizing reaction. The nanoholes 42 grow from the depressions 47 described above. Thus, as shown in FIG. 4, nanoholes 42 are formed on the surface of the substrate layer 41. Thereafter, the substrate layer 41 is immersed in a phosphoric acid solution. The inner peripheral surface of the nanohole 42 is etched based on the reaction with the phosphoric acid solution. Thus, the diameter of the nanohole 42 is set to, for example, about 10 nm. Similarly, the depth of the nanoholes 42 is set to about 3 O nm. The portion that is not anodized forms an aluminum intermediate layer 38.
次に、 ナノ粒子 4 3のナノホール 4 2への充填方法を簡単に説明する。 ナノ粒 子 4 3の形成にあたって周知のスーパ一ハイドライド法ゃポリオール法が用いら れればよい。 ナノ粒子 4 3の直径は例えば 7 n m程度に設定される。 こうして形 成された個々のナノ粒子 4 3は有機化合物すなわち有機安定剤で包まれる。 有機 安定剤は例えばカルボン酸 R— C O OHゃァミン R— NH 2から構成されればよ い。 このとき、 Rは直鎖または分岐のアルキルおよびアルケニル炭化水素が用い られればよい。 有機安定剤に包まれるナノ粒子 4 3は特定の有機溶剤に添加され る。 有機溶剤中でナノ粒子 4 3は再分散する。 再分散にあたってへキサンやヘプ タン、 オクタンといった有機溶剤が用いられればよい。 Next, a method of filling the nanoparticles 43 into the nanoholes 42 will be briefly described. The well-known super hydride method / polyol method may be used for the formation of the nanoparticles 43. The diameter of the nanoparticles 43 is set to, for example, about 7 nm. The individual nanoparticles 43 thus formed are enveloped with an organic compound, ie an organic stabilizer. The organic stabilizer may be composed of, for example, carboxylic acid R—CO OHamine R—NH 2 . In this case, R may be a linear or branched alkyl or alkenyl hydrocarbon. The nanoparticles 43 wrapped in the organic stabilizer are added to a specific organic solvent. The nanoparticles 43 redisperse in the organic solvent. An organic solvent such as hexane, heptane or octane may be used for redispersion.
続いて、 前述のナノホール 4 2を有する基質層 4 1は用意される。 例えば図 5 に示されるように、 形成されたナノ粒子 4 3はナノホール 4 2に充填される。 基 質層 4 1の表面に、 有機安定剤に包まれるナノ粒子 4 3を含む液体が塗布される。 塗布にあたつて例えばスピンコート法やディップ法が実施されればよレ ¾。  Subsequently, the substrate layer 41 having the aforementioned nanoholes 42 is prepared. For example, as shown in FIG. 5, the formed nanoparticles 43 are filled in the nanoholes 42. A liquid containing nanoparticles 43 wrapped in an organic stabilizer is applied to the surface of the base layer 41. For example, a spin coating method or a dipping method may be applied to the application.
続いて、 図 6に示されるように、 ナノホール 4 2から基質層 4 1の表面に溢れ るナノ粒子 4 3は拭い去られる。 ナノ粒子 4 3の除去にあたって基板 3 1は回転 させられる。 このとき、 基質層 4 1の表面にはワイパー 4 9が押し当てられる。. ワイパー 4 9は例えばゴムといった弾性体から構成されればよい。 ワイパー 4 9 に基づき基質層 4 1の表面に残存するナノ粒子 4 3は確実に拭い去られる。 こう してナノ粒子 4 3はナノホール 4 2内に完全に収容される。 Subsequently, as shown in FIG. 6, the nanoparticles 43 overflowing from the nanoholes 42 to the surface of the substrate layer 41 are wiped off. In removing the nanoparticles 43, the substrate 31 is rotated. At this time, a wiper 49 is pressed against the surface of the substrate layer 41. The wiper 49 may be made of an elastic material such as rubber. The nanoparticles 43 remaining on the surface of the substrate layer 41 based on the wiper 49 are reliably wiped off. like this As a result, the nanoparticles 43 are completely contained in the nanoholes 42.
以上のように製造された磁気ディスク 1 3では、 基質層 4 1の表面に、 特定の 溶媒中にナノ粒子 4 3を含む液体が塗布されることから、 ナノ粒子 4 3は比較的 に簡単にナノホール 4 2内に流れ込むことができる。 しかも、 微小粒ホール 4 2 から基質層 4 1の表面に溢れるナノ粒子 4 3は拭い去られる。 磁性体のナノ粒子 4 3はナノホール 4 2内にのみ残存することができる。  In the magnetic disk 13 manufactured as described above, the liquid containing the nanoparticles 43 in a specific solvent is applied to the surface of the substrate layer 41, so that the nanoparticles 43 are relatively easily formed. It can flow into the nanoholes 42. In addition, the nanoparticles 43 overflowing from the minute holes 42 to the surface of the substrate layer 41 are wiped off. The magnetic nanoparticles 43 can remain only in the nanoholes 42.
以上のような磁気ディスク 1 3では、 前述されるように、 記録磁性層 3 9は非 磁性体の基質層 4 1と、 磁性体のナノ粒子 4 3とから構成されればよい。 その一 方で、 基質層 4 1が磁性体から構成され、 ナノ粒子 4 3が非磁性体されてもよい。 同様に、 基質層 4 1およびナノ粒子 4 3のうち一方は導電体から構成され、 他方 は絶縁体から構成されてもよい。  In the magnetic disk 13 as described above, the recording magnetic layer 39 may be composed of the nonmagnetic substrate layer 41 and the magnetic nanoparticles 43 as described above. On the other hand, the substrate layer 41 may be made of a magnetic material, and the nanoparticles 43 may be made of a non-magnetic material. Similarly, one of the substrate layer 41 and the nanoparticles 43 may be made of a conductor, and the other may be made of an insulator.
図 7は、 本発明の第 2実施形態に係る磁気ディスク 1 3 aの断面構造を詳細に 示す。 この磁気ディスク 1 3 aはいわゆる垂直磁気記録媒体として構成される。 磁気ディスク 1 3 aは、 支持体としての基板 5 1と、 この基板 5 1の表裏面に広 がる多層構造膜 5 2とを備える。 基板 5 1は、 例えば、 ディスク形の S i本体 5 3と、 S i本体 5 3の表裏面に広がる非晶質の S i〇2膜 5 4とで構成されれば よい。 ただし、 基板 5 1にはガラス基板やアルミニウム基板、. セラミック基板が 用いられてもよい。 多層構造膜 5 2に磁気情報は記録される。 多層構造膜 5 2の 表面は、 例えばダイヤモンドライクカーボン (D L C) 膜といった保護膜 5 5や、 例えばパーフルォロポリエーテル (P F P E) 膜といった潤滑膜 5 6で被覆され る。 FIG. 7 shows a detailed cross-sectional structure of the magnetic disk 13a according to the second embodiment of the present invention. This magnetic disk 13a is configured as a so-called perpendicular magnetic recording medium. The magnetic disk 13a includes a substrate 51 as a support, and a multilayer structure film 52 extending on the front and back surfaces of the substrate 51. Substrate 5 1, for example, the S i body 3 of the disk-shaped, may be made by the S i amorphous S I_〇 2 film 5 4 over the front and back surfaces of the main body 3. However, as the substrate 51, a glass substrate, an aluminum substrate, or a ceramic substrate may be used. Magnetic information is recorded on the multilayer structure film 52. The surface of the multilayer structure film 52 is covered with a protective film 55 such as a diamond-like carbon (DLC) film and a lubricating film 56 such as a perfluoropolyether (PFPE) film.
多層構造 J3莫 5 2は、 基板 5 1の表面に広がる裏打ち層 5 7を備える。 裏打ち層 5 7は例えば F e T a C膜や N i F e膜といった軟磁性体から構成されればよい。 ここでは、 裏打ち層 5 7に例えば膜厚 2 0 0 ] 111程度の?6丁& ( 膜が用ぃられ ればよい。 裏打ち層 5 7では基板 5 1の表面に平行に規定される面内方向に磁ィ匕 容易軸は確立される。  The multilayer structure J3 includes a backing layer 57 extending on the surface of the substrate 51. The backing layer 57 may be made of a soft magnetic material such as a FeTaC film or a NiFe film. Here, the backing layer 57 has a thickness of, for example, about 200] 111? In the backing layer 57, an easy axis is established in an in-plane direction defined in parallel with the surface of the substrate 51.
裏打ち層 5 7の表面には中間層 5 8が広がる。 中間層 5 8は例えば炭素膜とい つた非磁性体から構成されればよい。 ここでは、 中間層 5 8に例えば膜厚 5 n m 程度の炭素膜が用いられればよい。 中間層 5 8の表面には構造体すなわち記録磁性層 5 9が広がる。 記録磁性層 5 9の膜厚は例えば 3 0 n m程度に設定されればよい。 記録磁性層 5 9は、 中間層 5 8の表面に広がる微小粒子すなわちナノ金属粒子 6 1の集合体を備える。 ナノ 金属粒子 6 1は例えば F e、 C oおよび N iの少なくともいずれかを含む磁性体 の微小金属粒子から構成されればよい。 ナノ金属粒子 6 1にはその他に P tや P dといった材料が添加されてもよい。 ここでは、 ナノ金属粒子 6 1に例えば磁性 の F e P t合金が用いられればよい。 こういったナノ金属粒子 6 1は結晶粒から 構成される。 個々の結晶粒では基板 5 1の表面に直交する垂直方向に磁化容易軸 が確立される。 An intermediate layer 58 spreads on the surface of the backing layer 57. The intermediate layer 58 may be made of a non-magnetic material such as a carbon film. Here, for example, a carbon film having a thickness of about 5 nm may be used for the intermediate layer 58. The structure, that is, the recording magnetic layer 59 is spread on the surface of the intermediate layer 58. The thickness of the recording magnetic layer 59 may be set to, for example, about 30 nm. The recording magnetic layer 59 includes an aggregate of fine particles, that is, nano metal particles 61, which spread on the surface of the intermediate layer 58. The nano metal particles 61 may be made of, for example, magnetic fine metal particles containing at least one of Fe, Co, and Ni. In addition, materials such as Pt and Pd may be added to the nano metal particles 61. Here, for example, a magnetic FePt alloy may be used for the nano metal particles 61. These nano metal particles 61 are composed of crystal grains. In each crystal grain, an easy axis of magnetization is established in a perpendicular direction perpendicular to the surface of the substrate 51.
ナノ金属粒子 6 1の直径は例えば 2 n m〜 1 0 nmの範囲に設定されればよい。 ナノ金属粒子 6 1同士の間隔は 0 . 2 n m〜 5 . 0 nmの範囲で設定されればよ レ^ ナノ金属粒子 6 1の平均粒径 Dに対する粒径分布の標準偏差 σの比率すなわ ち粒径分散 σ ZDは 1 0 %以下に設定されればよい。  The diameter of the nano metal particles 61 may be set, for example, in the range of 2 nm to 10 nm. The distance between the nano metal particles 61 may be set in the range of 0.2 nm to 5.0 nm. ^ The ratio of the standard deviation σ of the particle size distribution to the average particle size D of the nano metal particles 61 That is, the particle size distribution σ ZD may be set to 10% or less.
記録磁性層 5 9ではナノ金属粒子 6 1同士の間に炭素原子 6 2が存在する。 炭 素原子 6 2はナノ金属粒子 6 1同士をつなぎ合わせる。 記録磁性層 5 9では、 ナ ノ金属粒子 6 1を構成する原子の原子数および炭素原子 6 2の原子数の総計に対 して炭素原子 6 2単独の原子数は 4 5原子%〜 9 6原子%の範囲に設定される。 次に磁気ディスク 1 3 aの製造方法を詳述する。 まず、 ディスク形の基板 5 1 が用意される。 基板 5 1の表面には裏打ち層 5 7や中間層 5 8が順番に形成され る。 裏打ち層 5 7や中間層 5 8の形成にあたって例えばスパッタリング法や真空 蒸着法が用いられればよい。 続いて中間層 5 8の表面にはナノ金属粒子 6 1の集 合体が形成される。 形成方法の詳細は後述される。 ナノ金属粒子 6 1の集合体の 表面には保護膜 5 5や潤滑膜 5 6が形成される。 保護膜 5 5の形成には例えばス パッタリング法が用いられればよい。 潤滑膜 5 6は例えばディップ法に基づき塗 布されればよい。  In the recording magnetic layer 59, carbon atoms 62 exist between the nano metal particles 61. The carbon atoms 62 link the nanometal particles 61 together. In the recording magnetic layer 59, the number of atoms of carbon atoms 62 alone is 45 atomic% to 96% of the total number of atoms constituting the nano metal particles 61 and the total number of carbon atoms 62. It is set in the range of atomic%. Next, a method of manufacturing the magnetic disk 13a will be described in detail. First, a disk-shaped substrate 51 is prepared. On the surface of the substrate 51, a backing layer 57 and an intermediate layer 58 are sequentially formed. In forming the backing layer 57 and the intermediate layer 58, for example, a sputtering method or a vacuum evaporation method may be used. Subsequently, an aggregate of nano metal particles 61 is formed on the surface of the intermediate layer 58. Details of the formation method will be described later. A protective film 55 and a lubricating film 56 are formed on the surface of the aggregate of the nano metal particles 61. For example, a sputtering method may be used to form the protective film 55. The lubricating film 56 may be applied based on, for example, a dip method.
ナノ金属粒子 6 1の集合体の形成にあたって、 例えばへキサンといった有機溶 剤中にナノ金属粒子 6 1を含む液体は用意される。 ナノ金属粒子 6 1は例えば F e P t合金から構成されればよい。 ナノ金属粒子 6 1の直径は例えば 7 n m程度 に設定される。 個々のナノ金属粒子 6 1は有機化合物すなわち有機安定剤で包ま れる。 有機安定剤は例えばカルボン酸 R _ C〇〇Hゃァミン R _ NH 2で構成さ れればよい。 このとき、 Rには直鎖または分岐のアルキルやアルケニル炭化水素 が用いられればよい。 有機安定剤中の炭素原子の原子数は、 微小金属粒子を構成 する原子の原子数と有機化合物中の炭素原子の原子数との総計に対して 4 5原 子%〜 9 6原子%の範囲で設定される。 In forming an aggregate of the nanometal particles 61, a liquid containing the nanometal particles 61 in an organic solvent such as hexane is prepared. The nano metal particles 61 may be made of, for example, an FePt alloy. The diameter of the nano metal particles 61 is set to, for example, about 7 nm. Individual nanometal particles 61 are wrapped with an organic compound or organic stabilizer. It is. The organic stabilizer may be composed of, for example, a carboxylic acid R — C〇〇Hamine R — NH 2 . At this time, a linear or branched alkyl or alkenyl hydrocarbon may be used for R. The number of carbon atoms in the organic stabilizer is in the range of 45 atomic% to 96 atomic% with respect to the total number of atoms constituting the fine metal particles and the number of carbon atoms in the organic compound. Is set by
ナノ金属粒子 6 1および有機安定剤は有機溶剤とともに中間層 5 8の表面に塗 布される。 塗布にあたって例えばスピンコート法やディップ法が用いられればよ い。 その後、 有機溶剤は乾燥する。 ナノ金属粒子 6 1および有機安定剤は中間層 5 8の表面に残存する。 前述のように比較的に多量の有機安定剤が有機溶剤中に 含まれることから、 図 8に示されるように、 中間層 5 8の表面ではナノ金属粒子 6 1の分布に濃淡が生じる。 ナノ金属粒子 6 1および有機安定剤で構成される液 層 6 3の表面には凹凸が形成される。  The nano metal particles 61 and the organic stabilizer are coated on the surface of the intermediate layer 58 together with the organic solvent. For application, for example, a spin coating method or a dipping method may be used. Thereafter, the organic solvent is dried. The nano metal particles 61 and the organic stabilizer remain on the surface of the intermediate layer 58. As described above, since a relatively large amount of the organic stabilizer is contained in the organic solvent, as shown in FIG. 8, on the surface of the intermediate layer 58, the distribution of the nanometal particles 61 is shaded. Irregularities are formed on the surface of the liquid layer 63 composed of the nanometal particles 61 and the organic stabilizer.
続レて中間層 5 8の表面では加熱処理が施される。 例えば窒素ガスといった不 活性ガス雰囲気下で有機安定剤は 1 0 0 °C〜3 0 0 °Cといった高温に曝される。 加熱処理は例えば 1分〜 6 0分にわたって持続される。 その結果、 図 9に示され るように、 中間層 5 8の表面ではナノ金属粒子 6 1の分布は均一ィ匕される。 ナノ 金属粒子 6 1および有機安定剤で構成される液層 6 3の表面には平坦面が確立さ れる。 凹凸は解消される。  Subsequently, the surface of the intermediate layer 58 is subjected to a heat treatment. The organic stabilizer is exposed to a high temperature such as 100 ° C. to 300 ° C. in an atmosphere of an inert gas such as nitrogen gas. The heat treatment is continued for, for example, 1 minute to 60 minutes. As a result, as shown in FIG. 9, the distribution of the nano metal particles 61 is uniformly distributed on the surface of the intermediate layer 58. A flat surface is established on the surface of the liquid layer 63 composed of the nano metal particles 61 and the organic stabilizer. Unevenness is eliminated.
その後、 真空環境下でナノ金属粒子 6 1にァニール処理が施される。 ァニ一ル 処理にあたって基板 5 1はァニールチャンバ内に設置される。 チャンバ内では 3 x l O— 5 [ P a ] 以下の真空環境が確立される。 チャンパ内の温度は 2 0 0 °C 〜9 0 0。Cの範囲で設定されればよい。 例えば 3 0分間にわたって 8 0 0 °Cの温 度が維持されればよい。 チャンバ内の温度は室温から 8 0 0でまで 1 0分間で上 昇すればよい。 加熱中、 ナノ金属粒子 6 1には所定の磁場が適用される。 磁場の 大きさは例えば 0 . 1〜1 0 . 0 [T] の範囲で設定されればよい。 加熱に基づ き個々のナノ金属粒子 6 1は結晶化する。 磁場の働きでナノ金属粒子 6 1の磁ィ匕 容易軸は所定の方向に揃えられる。 その後、 基板 5 1は室温まで冷却される。 以上のような製造方法によれば、 比較的に多量の有機安定剤の働きで、 ァニ一 ル処理の実施にも拘わらずナノ金属粒子 6 1の凝集は回避されることができる。 ナノ金属粒子 6 1は微細な結晶粒のまま維持される。 いわゆる磁区は微細化され る。 磁区の微細化は記録密度の向上に大いに貢献する。 Thereafter, an annealing treatment is applied to the nano metal particles 61 in a vacuum environment. In the annealing process, the substrate 51 is set in an annealing chamber. A vacuum environment of 3 xl O- 5 [Pa] or less is established in the chamber. The temperature inside the champer is 200 ° C to 900 ° C. What is necessary is just to set in the range of C. For example, a temperature of 800 ° C. may be maintained for 30 minutes. The temperature in the chamber may be raised from room temperature to 800 in 10 minutes. During heating, a predetermined magnetic field is applied to the nanometal particles 61. The magnitude of the magnetic field may be set, for example, in the range of 0.1 to 10.0 [T]. The individual nano metal particles 61 crystallize based on the heating. By the action of the magnetic field, the easy axis of the nano metal particles 61 is aligned in a predetermined direction. Thereafter, the substrate 51 is cooled to room temperature. According to the above-described production method, the aggregation of the nano metal particles 61 can be avoided by the action of the relatively large amount of the organic stabilizer despite the execution of the annealing treatment. The nano metal particles 61 are maintained as fine crystal grains. So-called magnetic domains are refined. Miniaturization of magnetic domains greatly contributes to improvement of recording density.
しかも、 ァニール処理に先立って加熱処理が実施されることから、 有機安定剤 の増量にも拘わらず、 ナノ金属粒子 6 1および有機安定剤で構成される液層 6 3 の表面には平坦面が確立される。 磁気ディスク 1 3 aの表面で凹凸は大幅に抑制 される。 したがって、 ハードディスク駆動装置 1 1では、 浮上ヘッドスライダ 1 9は確実に安定した姿勢で浮上し続けることができる。  Moreover, since the heat treatment is performed prior to the annealing treatment, a flat surface is formed on the surface of the liquid layer 63 composed of the nanometal particles 61 and the organic stabilizer despite the increase in the amount of the organic stabilizer. Is established. Irregularities are greatly suppressed on the surface of the magnetic disk 13a. Therefore, in the hard disk drive 11, the flying head slider 19 can reliably continue to fly in a stable posture.
本発明者は、 F E— S EM (電界放射型走査電子顕微鏡) の画像に基づきナノ 金属粒子 6 1の集合体を観察した。 観察にあたって第 1具体例および第 1比較例 は用意された。 第 1具体例では、 ナ 金属粒子 6 1および有機安定剤の塗布にあ たって従来よりも多量の有機安定剤がナノ金属粒子 6 1の周囲に配置された。 第 1具体例では、 ナノ金属粒子 6 1および有機安定剤の塗布にあたって従来と同様 に少量の有機安定剤がナノ金属粒子 6 1の周囲に配置された。 ここで、 少量とは、 個々のナノ金属粒子 6 1の周囲に付着する最大限の分子数を意味する。 したがつ て、 第 1具体例では、 有機安定剤がナノ金属粒子 6 1に付着するだけでなく、 ナ ノ金属粒子 6 1同士の間で有機安定剤が漂うことが予想される。 いずれの試料で も前述のようにナノ金属粒子 6 1にァニール処理が施された。 観察の結果、 第 1 具体例では微細なナノ金属粒子 6 1すなわち結晶粒が維持されることが確認され た。 ただし、 ナノ金属粒子 6 1の集合体の表面には比較的に大きな段差の凹凸が 確認された。 その一方で、 第 1比較例では、 ナノ金属粒子 6 1の集合体の表面で 平坦面は維持されるものの、 ナノ金属粒子 6 1同士の合体に基づき結晶粒が肥大 化することが確認された。 .  The present inventor observed an aggregate of nano metal particles 61 based on an image of FE-SEM (field emission scanning electron microscope). For observation, the first specific example and the first comparative example were prepared. In the first specific example, in applying the metal particles 61 and the organic stabilizer, a larger amount of the organic stabilizer than before was arranged around the nano metal particles 61. In the first specific example, a small amount of the organic stabilizer was disposed around the nanometal particles 61 in the same manner as in the past when applying the nanometal particles 61 and the organic stabilizer. Here, “small amount” means the maximum number of molecules attached around each individual nano metal particle 61. Therefore, in the first specific example, it is expected that not only the organic stabilizer adheres to the nanometal particles 61 but also the organic stabilizer drifts between the nanometal particles 61. In each of the samples, the nano metal particles 61 were subjected to an annealing treatment as described above. As a result of the observation, it was confirmed that fine nano metal particles 61, that is, crystal grains were maintained in the first specific example. However, relatively large unevenness was observed on the surface of the aggregate of the nanometal particles 61. On the other hand, in the first comparative example, it was confirmed that although the flat surface was maintained on the surface of the aggregate of the nanometal particles 61, the crystal grains were enlarged based on the coalescence of the nanometal particles 61. . .
同様に、 本発明者は、 ナノ金属粒子 6 1および有機安定剤の塗布の時点で、 ナ ノ金属粒子 6 1および有機安定剤で構成される液層 6 3の表面を観察した。 観察 には第 1具体例および第 1比較例が用いられた。 第 1具体例では、 液層 6 3の表 面に凹凸が観察された。 したがって、 こういった凹凸はァニール処理の前後で維 持されることが実証された。 その一方で、 第 1比較例では、 ナノ金属粒子 6 1お よび有機安定剤で構成される液層 6 3の表面に平坦面が確保された。  Similarly, the present inventors observed the surface of the liquid layer 63 composed of the nanometal particles 61 and the organic stabilizer at the time of the application of the nanometal particles 61 and the organic stabilizer. The first specific example and the first comparative example were used for observation. In the first specific example, irregularities were observed on the surface of the liquid layer 63. Therefore, it was demonstrated that these irregularities were maintained before and after the annealing treatment. On the other hand, in the first comparative example, a flat surface was secured on the surface of the liquid layer 63 composed of the nanometal particles 61 and the organic stabilizer.
さらに本発明者は A FM (原子間力顕微鏡) の画像に基づきナノ金属粒子 6 1 の集合体を観察した。 観察にあたって第 2具体例および第 2比較例は用意された。 いずれの試料でも、 前述の第 1具体例と同様に、 ナノ金属粒子 6 1および有機安 定剤の塗布にあたって従来よりも多量の有機安定剤がナノ金属粒子 6 1の周囲に 配置された。 いずれの試料でも前述のようにナノ金属粒子 6 1にァニール処理が 施された。 しカも、 第 2具体例ではァニール処理に先立って前述の加熱処理が実 施された。 ナノ金属粒子 6 1および有機安定剤は窒素雰囲気下で 5分間にわたつ て 2 0 0 °Cの高温に曝された。 その一方で、 第 2比較例ではナノ金属粒子 6 1お よび有機安定剤の塗布後にァニール処理が実施された。 すなわち、 第 2比較例で は前述の加熱処理は実施されなかった。 図 1 0に示されるように、 第 2具体例で はナノ金属粒子 6 1の集合体の表面に平坦面は確保された。 1 m四方で 4 4 p mの表面粗さ R aが記録された。 図 1 1から明らかなように、 第 2比較例ではナ ノ金属粒子 6 1の集合体の表面に凹凸は形成された。 1 ; m四方で 9 0 9 p mの 表面粗さ R aが記録された。 In addition, the present inventor has developed nano metal particles 6 1 based on AFM (atomic force microscope) images. Was observed. For observation, a second specific example and a second comparative example were prepared. In each of the samples, as in the first specific example described above, a larger amount of the organic stabilizer was disposed around the nanometal particles 61 than before in the application of the nanometal particles 61 and the organic stabilizer. As described above, the annealing treatment was performed on the nano metal particles 61 in all the samples. Also, in the second specific example, the above-described heat treatment was performed prior to the annealing treatment. The nanometal particles 61 and the organic stabilizer were exposed to a high temperature of 200 ° C. for 5 minutes under a nitrogen atmosphere. On the other hand, in the second comparative example, an annealing treatment was performed after the application of the nanometal particles 61 and the organic stabilizer. That is, in the second comparative example, the above-described heat treatment was not performed. As shown in FIG. 10, in the second specific example, a flat surface was secured on the surface of the aggregate of the nano metal particles 61. A surface roughness Ra of 44 pm over a 1 m square was recorded. As is clear from FIG. 11, irregularities were formed on the surface of the aggregate of the nano metal particles 61 in the second comparative example. 1; surface roughness Ra of 0.909 pm on m squares was recorded.
さらにまた、 本発明者は前述と同様に F E - S EMの画像に基づきナノ金属粒 子 6 1の集合体を観察した。 観察にあたって 3種類の試料は用意された。 いずれ の試料でも、 前述の第 1具体例と同様に、 ナノ金属粒子 6 1および有機安定剤の 塗布にあたって従来よりも多量の有機安定剤がナノ金属粒子 6 1の周囲に配置さ れた。 いずれの試料でも前述のようにナノ金属粒子 6 1にァニール処理が施され た。 ただし、 いずれの試料でもァニール処理に先立って前述の加熱処理が実施さ れた。 加熱時間は各試料ごとに 5分間、 3 0分間および 4 5分間に設定された。 加熱時間が 5分間や 3 0分間に設定されると、 微細なナノ金属粒子 6 1が維持さ れたまま、 ナノ金属粒子 6 1の集合体の表面で平坦面が確保された。 その一方で、 加熱時間が 4 5分に設定されると、 ナノ金属粒子 6 1の融合が観察された。 微細 なナノ金属粒子 6 1は確保されることができなかった。  Furthermore, the present inventor observed the aggregate of the nano metal particles 61 based on the FE-SEM image as described above. Three types of samples were prepared for observation. In each of the samples, a larger amount of the organic stabilizer was disposed around the nanometal particles 61 than before in the application of the nanometal particles 61 and the organic stabilizer as in the first specific example described above. In each of the samples, the nano metal particles 61 were subjected to an annealing treatment as described above. However, the heat treatment described above was performed prior to the annealing treatment in all samples. The heating time was set to 5 minutes, 30 minutes and 45 minutes for each sample. When the heating time was set to 5 minutes or 30 minutes, a flat surface was secured on the surface of the aggregate of the nanometal particles 61 while maintaining the fine nanometal particles 61. On the other hand, when the heating time was set at 45 minutes, fusion of the nanometal particles 61 was observed. Fine nano metal particles 61 could not be secured.
図 1 2は、 本発明の第 3実施形態に係る磁気ディスク 1 3 bの断面構造を詳細 に示す。 この磁気ディスク 1 3 bは面内磁気記録媒体として構成される。 磁気デ イスク 1 3 bは、 支持体としての基板 7 1と、 この基板 7 1の表裏面に広がる多 結晶構造膜 7 2とを備える。 基板 7 1は、 例えばガラス基板から構成されればよ レ^ ただし、 基板 7 1にはアルミニウム基板やシリコン基板、 セラミック基板が 用いられてもよい。 多結晶構造膜 7 2に磁気情報は記録される。 多結晶構造膜 7 2の表面は、 例えばダイヤモンドライクカーボン (D L C) 膜といった保護膜 7 3や、 例えばパーフルォロポリエーテル (P F P E) 膜といった潤滑膜 7 4で被 覆される。 FIG. 12 shows a cross-sectional structure of a magnetic disk 13b according to the third embodiment of the present invention in detail. This magnetic disk 13b is configured as an in-plane magnetic recording medium. The magnetic disk 13 b includes a substrate 71 as a support, and a polycrystalline structure film 72 extending on the front and back surfaces of the substrate 71. The substrate 71 may be made of, for example, a glass substrate. However, the substrate 71 may be an aluminum substrate, a silicon substrate, or a ceramic substrate. May be used. Magnetic information is recorded on the polycrystalline structure film 72. The surface of the polycrystalline structure film 72 is covered with a protective film 73 such as a diamond-like carbon (DLC) film and a lubricating film 74 such as a perfluoropolyether (PFPE) film.
多結晶構造膜 7 2は、 基層すなわち基板 7 1の表面に配置される微小粒子すな わちナノ粒子 7 5を備える。 ナノ粒子 7 5は基板 7 1の表面に途切れなく広がる 連続層を形成する。 ナノ粒子 7 5の連続層の厚さは例えば 2 0 nm程度に設定さ れればよい。 ナノ粒子 7 5は金属元素を含む。 こういった金属元素には例えば F eおよび P tが含まれればよい。 ここでは、 ナノ粒子 7 5に例えば F e P t合金 が用いられればよい。 ナノ粒子 7 5の直径は 2 nm〜l 0 nmの範囲に設定され ればよい。 ナノ粒子 7 5の平均粒径 Dに対する粒径分布の標準偏差びの比率すな わち粒径分散 σ /Dは 2 0 %以下に設定されればよい。  The polycrystalline structure film 72 includes fine particles, that is, nanoparticles 75 disposed on the surface of the base layer, that is, the substrate 71. The nanoparticles 75 form a continuous layer that extends continuously on the surface of the substrate 71. The thickness of the continuous layer of the nanoparticles 75 may be set to, for example, about 20 nm. The nanoparticles 75 contain a metal element. Such metal elements may include, for example, Fe and Pt. Here, for example, an Fe Pt alloy may be used for the nanoparticles 75. The diameter of the nanoparticles 75 may be set in the range of 2 nm to 10 nm. The ratio of the standard deviation of the particle size distribution to the average particle size D of the nanoparticles 75, that is, the particle size distribution σ / D, may be set to 20% or less.
なお、 図 1 2から明らかなように、 基板 7 1とナノ粒子 7 5との間には密着層 7 6が挟み込まれてもよい。 こういった密着層 7 6には例えば炭素膜が用いられ ることができる。 密着膜 7 6の働きによれば、 基板 7 1およびナノ粒子 7 5の間 の密着力は高められることができる。  As is clear from FIG. 12, an adhesion layer 76 may be interposed between the substrate 71 and the nanoparticles 75. For example, a carbon film can be used for such an adhesion layer 76. According to the function of the adhesive film 76, the adhesive force between the substrate 71 and the nanoparticles 75 can be increased.
ナノ粒子 7 5の表面には下地多結晶層 7 7が広がる。 下地多結晶層 7 7は、 ナ ノ粒子 7 5に基づき成長する結晶粒で構成される。 下地多結晶層 7 7は例えば Ρ tおよび P dを含む合金から構成されればよい。 ここでは、 下地多結晶層 7 7に 例えば膜厚 5 nm程度の P t P d膜が用いられる。  The underlying polycrystalline layer 77 spreads on the surface of the nanoparticles 75. The underlying polycrystalline layer 77 is composed of crystal grains that grow based on the nanoparticle 75. Base polycrystalline layer 77 may be made of, for example, an alloy containing Ρt and Pd. Here, for example, a PtPd film having a thickness of about 5 nm is used for the underlying polycrystalline layer 77.
下地多結晶層 7 7の表面には磁性多結晶層 7 8が広がる。 磁性多結晶層 7 8は、 下地多結晶層 7 7の個々の結晶粒から成長する結晶粒で構成される。 磁性多結晶 層 7 8に磁気情報は記録される。 磁性多結晶層 7 8は、 例えば C oや N i、 F e のいずれかを少なくとも含む合金から構成されればよい。 ここでは、 例えば膜厚 1 5 n m程度の C o C r P t膜が用いられる。  The magnetic polycrystalline layer 78 spreads on the surface of the base polycrystalline layer 77. Magnetic polycrystalline layer 78 is composed of crystal grains that grow from individual crystal grains of base polycrystalline layer 77. Magnetic information is recorded on the magnetic polycrystalline layer 78. The magnetic polycrystalline layer 78 may be made of, for example, an alloy containing at least one of Co, Ni, and Fe. Here, for example, a CoCrPt film having a thickness of about 15 nm is used.
こういった多結晶構造膜 7 2によれば、 下地多結晶層 7 7の結晶粒はナノ粒子 7 5に基づき成長する。 ナノ粒子 7 5の大きさや分散は十分に制御されることか ら、 下地多結晶層 7 7では結晶粒の大きさや分布は確実に制御されることができ る。 磁性多結晶層 7 8は、 下地多結晶層 7 7の個々の結晶粒から成長する結晶粒 で構成されることから、 結晶粒の大きさや分布は確実に制御されることができる。 磁気ディスク 1 3 bでは磁気情報の記録密度はこれまで以上に高められることが できる。 According to such a polycrystalline structure film 72, the crystal grains of the underlying polycrystalline layer 77 grow based on the nanoparticles 75. Since the size and dispersion of the nanoparticles 75 are sufficiently controlled, the size and distribution of crystal grains in the underlying polycrystalline layer 77 can be reliably controlled. The magnetic polycrystalline layer 7 8 is composed of crystal grains that grow from the individual crystal grains of the underlying polycrystalline layer 7 7. Therefore, the size and distribution of the crystal grains can be reliably controlled. In the magnetic disk 13b, the recording density of magnetic information can be increased more than ever.
次に磁気ディスク 1 3 bの製造方法を簡単に説明する。 まず、 ディスク形の基 板 7 1が用意される。 基板 7 1の表面には炭素の密着層 7 6が形成される。 密着 層 7 6の形成にあたって例えば真空蒸着法は用いられる。 密着層 7 6の膜厚は例 えば 4 nm程度に設定されればよい。  Next, a method of manufacturing the magnetic disk 13b will be briefly described. First, a disk-shaped substrate 71 is prepared. An adhesion layer 76 of carbon is formed on the surface of the substrate 71. In forming the adhesion layer 76, for example, a vacuum evaporation method is used. The thickness of the adhesion layer 76 may be set to, for example, about 4 nm.
密着層 7 6の表面にはいわゆるスピンコート法に基づきナノ粒子 7 5が塗布さ れる。 スピンコート法の実施にあたって基板 7 1は 3 0 0 r pmの回転速度で駆 動される。 その後、 基板 7 1は例えばへキサン雰囲気下に置かれる。 続いて基板 7 1の回転速度は 6 0 r p mに落とされる。 このとき、 基板 7 1の表面には、 有 機溶剤中でナノ粒子を含む液体が滴下される。 滴下後、 基板 7 1の回転速度は 1 0 0 0 r p mに高められる。 1 0 0 0 r pmの回転が 1 0秒にわたって持続され る結果、 滴下された液体は基板 7 1の表面に満逼なく均一に行き渡る。  Nanoparticles 75 are applied to the surface of the adhesion layer 76 based on a so-called spin coating method. In carrying out the spin coating method, the substrate 71 is driven at a rotation speed of 300 rpm. Thereafter, the substrate 71 is placed in, for example, a hexane atmosphere. Subsequently, the rotation speed of the substrate 71 is reduced to 60 rpm. At this time, a liquid containing nanoparticles is dropped on the surface of the substrate 71 in an organic solvent. After the dropping, the rotation speed of the substrate 71 is increased to 1000 rpm. As a result of the rotation of 100 rpm being maintained for 10 seconds, the dropped liquid uniformly spreads over the surface of the substrate 71 without being tight.
その後、 基板 7 1の表面は窒素ガス雰囲気に曝される。 窒素ガスの働きで基板 7 1の表面では残存するへキサンは乾燥する。 こうしてナノ粒子 7 5の連続膜は 形成される。 いわゆる自己組織化に基づきナノ粒子 7 5は規則的な配列で配置さ れる。  After that, the surface of the substrate 71 is exposed to a nitrogen gas atmosphere. The hexane remaining on the surface of the substrate 71 is dried by the action of nitrogen gas. Thus, a continuous film of the nanoparticles 75 is formed. The nanoparticles 75 are arranged in a regular array based on so-called self-organization.
その後、 基板 7 1はスパッタリング装置に装着される。 P d P t夕ーゲットに 基づきスパッタリングは実施される。 その結果、 P d P t合金膜すなわち下地多 結晶層 7 7は形成される。 下地多結晶層 7 7ではナノ粒子 7 5に基づき個々の 晶粒は成長していく。 下地多結晶層 7 7の膜厚は例えば 5 nm程度に設定されれ ばよい。  Thereafter, the substrate 71 is mounted on a sputtering device. Sputtering is performed based on the PdPt target. As a result, a PdPt alloy film, that is, an underlying polycrystalline layer 77 is formed. In the base polycrystalline layer 77, individual crystal grains grow based on the nanoparticles 75. The thickness of underlying polycrystalline layer 77 may be set to, for example, about 5 nm.
続いてスパッタリング装置では C o C r P tターゲットに基づきスパッタリン グが実施される。 下地多結晶層 7 7上には磁性多結晶層 7 8が形成される。 磁性 多結晶層 7 8の結晶粒は下地多結晶層 7 7の結晶粒からェピタキシャル成長に基 づき成長する。 磁性多結晶層 7 8の膜厚は例えば 1 5 nm程度に設定されればよ い。  Subsequently, in the sputtering apparatus, sputtering is performed based on the CoCrPt target. Magnetic polycrystalline layer 78 is formed on base polycrystalline layer 77. The crystal grains of the magnetic polycrystalline layer 78 grow from the crystal grains of the underlying polycrystalline layer 77 based on the epitaxial growth. The thickness of the magnetic polycrystalline layer 78 may be set to, for example, about 15 nm.
次にナノ粒子 7 5の形成方法を簡単に説明する。 例えばアルゴンガス雰囲気下 でフラスコは用意される。 フラスコ内には、 197mg (0. 5mM相当) のビ スァセチルァセトナト白金および 39 Omgの 1,2-へキサデカンジオールが配置 される。 フラスコには 20mL (ミリリットル) のジォクチルエーテルが加えら れる。 その後、 フラスコには 0. 32mL (1. OmM相当) のォレイン酸およ び 0. 34mL (1. 0 mM相当) のォレイルァミンが加えられる。 続いてフラ スコには 0. 13mL (1. OmM相当) の鉄カルポニル F e (CO) 5が加え られる。 こうしてフラスコ内で生成される溶液は 230°Cの温度下で撹拌される。 その結果、 溶液内ではィ匕学反応が引き起こされる。 鉄白金 (FePt) ナノ粒子 は生成される。 ナノ粒子はォレイン酸ゃォレイルァミンといつた有機安定剤に包 まれる。 Next, a method of forming the nanoparticles 75 will be briefly described. For example, under argon gas atmosphere A flask is prepared. In the flask are placed 197 mg (equivalent to 0.5 mM) of bis-acetylacetonato platinum and 39 Omg of 1,2-hexadecanediol. The flask is charged with 20 mL (milliliter) of octyl ether. Then, 0.32 mL (equivalent to 1. OmM) of oleic acid and 0.34 mL (equivalent to 1.0 mM) of oleylamine are added to the flask. Subsequently, 0.13 mL (equivalent to 1. OmM) of iron carbonyl Fe (CO) 5 is added to the flask. The solution thus formed in the flask is stirred at a temperature of 230 ° C. As a result, a diversion reaction occurs in the solution. Iron platinum (FePt) nanoparticles are produced. The nanoparticles are encapsulated in an organic stabilizer such as oleylamine oleate.
その後、 フラスコ内の溶液は室温まで冷却される。 フラスコ内には 4 OmLの エタノ一ルが加えられる。 遠心分離に基づきナノ粒子および有機安定剤の沈殿物 が取り出される。 取り出されたナノ粒子および有機安定剤はへキサンに添加され る。 こうしてへキサン中に分散するナノ粒子は得られる。 以上のような条件に従 えば、 平均粒径 4. 3 nmの F e P tナノ粒子は生成されることができる。  Thereafter, the solution in the flask is cooled to room temperature. 4 OmL of ethanol is added to the flask. The precipitate of nanoparticles and organic stabilizer is removed based on centrifugation. The extracted nanoparticles and the organic stabilizer are added to hexane. Thus, nanoparticles dispersed in hexane are obtained. According to the above conditions, FePt nanoparticles having an average particle diameter of 4.3 nm can be generated.
図 13は、 本発明の第 3実施形態の変形例に係る磁気ディスク 13 cの断面構 造を詳細に示す。 磁気ディスク 13 cはいわゆる垂直磁気記録媒体として構成さ れる。 磁気ディスク 13cは、 支持体としての基板 91と、 この基板 91の表裏 面に広がる多結晶構造膜 92とを備える。 多結晶構造膜 92は、 基板 91の表面 に広がる裏打ち層 95を備える。 裏打ち層 95は例えば F e T a C膜や N i F e 膜といった軟磁性体から構成されればよい。 ここでは、 裏打ち層 95に例えば膜 厚 20 Onm程度の FeTaC膜が用いられればよい。 裏打ち層 95では基板 9 1の表面に平行に規定される面内方向に磁ィヒ容易軸は確立される。  FIG. 13 shows a detailed cross-sectional structure of a magnetic disk 13c according to a modification of the third embodiment of the present invention. The magnetic disk 13c is configured as a so-called perpendicular magnetic recording medium. The magnetic disk 13c includes a substrate 91 as a support, and a polycrystalline structure film 92 extending on the front and back surfaces of the substrate 91. The polycrystalline structure film 92 includes a backing layer 95 extending on the surface of the substrate 91. The backing layer 95 may be made of a soft magnetic material such as a FeTaC film or a NiFe film. Here, for example, an FeTaC film having a film thickness of about 20 Onm may be used for the backing layer 95. In the backing layer 95, an easy magnetic axis is established in an in-plane direction defined parallel to the surface of the substrate 91.
多結晶構造膜 92は、 基層すなわち裏打ち層 95の表面に配置される微小粒子 すなわちナノ粒子 96を備える。 ナノ粒子 96は裏打ち層 95の表面に途切れな く広がる連続層すなわち非磁性層を形成する。 ナノ粒子 96の連続層の厚さは例 えば 20 nm程度に設定されればよい。 ナノ粒子 96の直径は 2 nm〜 10 nm の範囲に設定されればよい。 ナノ粒子 96の平均粒径 Dに対する粒径分布の標準 偏差 σの比率すなわち粒径分散 σ/Dは 20 %以下に設定されればよい。 ナノ粒子 9 6の表面には磁性多結晶層 9 7が広がる。 磁性多結晶層 9 7は、 ナ ノ粒子 9 6に基づき成長する結晶粒で構成される。 磁性多結晶層 9 7に磁気情報 は記録される。 磁性多結晶層 9 7は、 例えば C oや N i、 F eのいずれかを少な くとも含む合金から構成されればよい。 ここでは、 例えば膜厚 1 5 nm程度の C 0 C r P t Ji奠が用いられる。 磁性多結晶層 9 7では基板 9 1の表面に直交する垂 直方向に磁化容易軸は確立される。 The polycrystalline structure film 92 includes microparticles or nanoparticles 96 disposed on the surface of the base layer or backing layer 95. The nanoparticles 96 form a continuous layer, ie, a non-magnetic layer, that extends continuously on the surface of the backing layer 95. The thickness of the continuous layer of the nanoparticles 96 may be set to, for example, about 20 nm. The diameter of the nanoparticles 96 may be set in the range of 2 nm to 10 nm. The ratio of the standard deviation σ of the particle size distribution to the average particle size D of the nanoparticles 96, that is, the particle size distribution σ / D may be set to 20% or less. The magnetic polycrystalline layer 97 spreads on the surface of the nanoparticles 96. The magnetic polycrystalline layer 97 is composed of crystal grains that grow based on the nanoparticle 96. Magnetic information is recorded on the magnetic polycrystalline layer 97. The magnetic polycrystalline layer 97 may be made of, for example, an alloy containing at least one of Co, Ni, and Fe. In this case, for example, C 0 CrPt Ji-dian having a thickness of about 15 nm is used. In the magnetic polycrystalline layer 97, an easy axis of magnetization is established in a perpendicular direction perpendicular to the surface of the substrate 91.
なお、 図 1 3から明らかなように、 基板 9 1と裏打ち層 9 5との間には配向制 御層 9 8が挟み込まれてもよい。 こういった配向制御層 9 8には例えば C rや C rを含む合金膜が用いられることができる。 配向制御膜 9 8の働きによれば、 磁 性多結晶層 9 8の結晶粒の配向は十分に揃えられることができる。  As apparent from FIG. 13, an orientation control layer 98 may be interposed between the substrate 91 and the backing layer 95. For such an orientation control layer 98, for example, Cr or an alloy film containing Cr can be used. According to the function of the orientation control film 98, the orientation of the crystal grains of the magnetic polycrystalline layer 98 can be sufficiently aligned.
こういった多結晶構造膜 9 2によれば、 磁性多結晶層 9 7の結晶粒はナノ粒子 9 6に基づき^長する。 ナノ粒子 9 6の大きさや分散は十分に制御されることか ら、 磁性多結晶層 9 7では結晶粒の大きさや分布は確実に制御されることができ る。  According to such a polycrystalline structure film 92, the crystal grains of the magnetic polycrystalline layer 97 are elongated based on the nanoparticles 96. Since the size and dispersion of the nanoparticles 96 are sufficiently controlled, the size and distribution of crystal grains in the magnetic polycrystalline layer 97 can be reliably controlled.
次に、 磁気ディスク 1 3 cの製造方法を簡単に説明する。 まず、 ディスク形の 基板 9 1が用意される。 基板 9 1には配向制御層 9 8や裏打ち層 9 6が形成され ればよい。 形成にあたって例えばスパッタリング法は用いられる。  Next, a method of manufacturing the magnetic disk 13c will be briefly described. First, a disk-shaped substrate 91 is prepared. The orientation control layer 98 and the backing layer 96 may be formed on the substrate 91. In the formation, for example, a sputtering method is used.
続いて、 裏打ち層 9 6の表面にはいわゆるスピンコート法に基づきナノ粒子 9 6が塗布される。 ナノ粒子 9 6の連続膜は形成される。 いわゆる自己組織ィ匕に基 づきナノ粒子 9 6は規則的な配列で配置される。  Subsequently, nanoparticles 96 are applied to the surface of the backing layer 96 based on a so-called spin coating method. A continuous film of nanoparticles 96 is formed. The nanoparticles 96 are arranged in a regular array based on the so-called self-organization.
続いて、 基板 9 1はスパッタリング装置に装着される。 C o C r P t夕ーゲッ トに基づきスパッタリングは実施される。 その結果、 C o C r P t合金膜すなわ ち磁性多結晶層 9 7は形成される。 磁性多結晶層 9 7ではナノ粒子 9 6に基づき 個々の結晶粒は成長していく。 磁性多結晶層 9 7の膜厚は例えば 1 5 nm程度に 設定されればよい。  Subsequently, the substrate 91 is mounted on a sputtering apparatus. Sputtering is performed based on the CoCrPt target. As a result, a CoCrPt alloy film, that is, a magnetic polycrystalline layer 97 is formed. In the magnetic polycrystalline layer 97, individual crystal grains grow based on the nanoparticles 96. The thickness of the magnetic polycrystalline layer 97 may be set to, for example, about 15 nm.
いずれの実施形態でもスピンコート法の実現にあたってスピンコ一夕は利用さ れることができる。 図 1 4はスピンコ一夕の構成を概略的に示す。 このスピンコ 一夕 1 0 1は密閉型のチヤンバ 1 0 2を備える。 チヤンバ 1 0 2内には回転軸 1 0 3が配置される。 この回転軸 1 0 3に磁気ディスク 1 3 ( 1 3 a、 1 3 b、 1 3 c ) は受け止められる。 回転軸 1 0 3の回転に伴い磁気ディスク 1 3は中心軸 回りで回転することができる。 In any of the embodiments, the spin-coating method can be used to realize the spin-coating method. FIG. 14 schematically shows the configuration of the spinco. This spinco 101 has a sealed chamber 102. A rotation axis 103 is arranged in the chamber 102. A magnetic disk 13 (13a, 13b, 1 3 c) is accepted. With the rotation of the rotating shaft 103, the magnetic disk 13 can rotate around the central axis.
チャンバ 1 0 3内の空間には第 1および第 2滴下ノズル 1 0 4、 1 0 5が臨む。 第 1滴下ノズル 1 0 4の先端は、 回転軸 1 0 3に装着される磁気ディスク 1 3の 表面に向き合わせられる。 第 1滴下ノズル 1 0 4は、 回転軸 1 0 3の中心軸を含 む 1垂直平面に沿って水平方向に移動することができる。 すなわち、 第 1滴下ノ ズル 1 0 4は、 回転軸 1 0 3に装着される磁気ディスク 1 3の半径方向に移動す ることができる。 第 1滴下ノズル 1 0 4には例えば所定の液溜めから液体が供給 される。 回転軸 1 0 3の回転と第 1滴下ノズル 1 0 4の水平移動との組み合わせ に基づき、 磁気ディスク 1 3上には例えば渦巻き形の経路に沿って液体が滴下さ れることができる。 こうした第 1滴下ノズル 1 0 4には、 前述のように有機溶剤 中でナノ粒子を含む液体が供給されればよい。  The first and second drip nozzles 104 and 105 face the space in the chamber 103. The tip of the first dripping nozzle 104 faces the surface of the magnetic disk 13 mounted on the rotating shaft 103. The first dropping nozzle 104 can move in a horizontal direction along one vertical plane including the center axis of the rotation axis 103. That is, the first dropping nozzle 104 can move in the radial direction of the magnetic disk 13 mounted on the rotating shaft 103. A liquid is supplied to the first dripping nozzle 104, for example, from a predetermined liquid reservoir. Based on the combination of the rotation of the rotating shaft 103 and the horizontal movement of the first dropping nozzle 104, the liquid can be dropped on the magnetic disk 13 along, for example, a spiral path. The liquid containing nanoparticles in the organic solvent may be supplied to the first dropping nozzle 104 as described above.
第 2滴下ノズル 1 0 5の先端には気化装置 1 0 6が向き合わせられる。 第 2滴 下ノズル 1 0 5から滴下される液体は気化装置 1 0 6で受け止められる。 チャン ノ 1 0 2内は、 気化装置 1 0 6で気化される気ィ匕ガスで満たされることができる。 チャンバ 1 0 2内では気化ガスの蒸気圧が蒸気圧センサ 1 0 7で検出される。 第 2滴下ノズル 1 0 5から滴下される液体の液量は検出される蒸気圧に基づき調整 されることができる。 こうした第 2滴下ノズル 1 0 5の働きでチャンバ 1 0 2内 にはへキサン雰囲気が確立されることができる。  A vaporizer 106 is opposed to the tip of the second drip nozzle 105. The liquid dropped from the second dropping nozzle 105 is received by the vaporizer 106. The inside of the channel 102 can be filled with a gas to be vaporized by the vaporizer 106. In the chamber 102, the vapor pressure of the vaporized gas is detected by the vapor pressure sensor 107. The amount of the liquid dropped from the second dropping nozzle 105 can be adjusted based on the detected vapor pressure. A hexane atmosphere can be established in the chamber 102 by the operation of the second dropping nozzle 105.
チャンバ 1 0 2にはガス導入口 1 0 8が形成される。 こういったガス導入口 1 0 8は、 回転軸 1 0 3に装着される磁気ディスク 1 3の表面に向き合わせられる。 こういったガス導入口 1 0 8の働きに基づき、'前述のように窒素ガスは磁気ディ スク 1 3の表面に向かって噴き出すことができる。 チャンバ 1 0 2にはドレイン 1 0 9が接続される。 余分な液体はドレイン 1 0 9からチャンバ 1 0 2外に排出 されることができる。  A gas inlet 108 is formed in the chamber 102. The gas inlet 108 is opposed to the surface of the magnetic disk 13 mounted on the rotating shaft 103. Based on the function of the gas inlet 108, nitrogen gas can be ejected toward the surface of the magnetic disk 13 as described above. A drain 109 is connected to the chamber 102. Excess liquid can be drained from the drain 109 out of the chamber 102.
ナノ粒子 4 3、 6 1、 7 5、 9 6は例えば以下の製造方法で製造されてもよい。 ナノ粒子の形成にあたって不揮発性の金属化合物が用意される。 金属化合物には、 例えばァセチルァセトナト塩が用いられることができる。 その他、 カルボン酸の 塩、 青酸の塩、 スルホン酸の塩、 ホスホン酸の塩から選択される有機酸の塩が用 いられてもよい。 こういった有機酸の塩では炭素数は 1〜20の範囲で設定され る。 さらに、 金属化合物には臭化物およびヨウ化物が用いられることができる。 こういった金属化合物に含まれる金属元素には、 例えば Fe、 Co、 N i、 P t、 C r、 Cu、 Ag、 Mnおよび P bが含まれればよい。 ナノ粒子の形成にあたつ て例えば 2種類以上の金属化合物が含まれてもよい。 The nanoparticles 43, 61, 75, and 96 may be produced by, for example, the following production method. In forming the nanoparticles, a nonvolatile metal compound is prepared. As the metal compound, for example, acetyl acetonato salt can be used. In addition, salts of organic acids selected from carboxylic acid salts, hydrocyanic acid salts, sulfonic acid salts, and phosphonic acid salts are used. May be. In these organic acid salts, the carbon number is set in the range of 1-20. Further, bromides and iodides can be used as the metal compound. The metal element contained in such a metal compound may include, for example, Fe, Co, Ni, Pt, Cr, Cu, Ag, Mn and Pb. In forming the nanoparticles, for example, two or more metal compounds may be included.
ナノ粒子の形成にあたって特定の有機溶媒が用意される。 有機溶媒には、 例え ば炭化水素、 ェ一テルおよびエステルといった非プロトン性の有機溶媒が用いら れることができる。 こういった有機溶媒では炭素数は 2〜 20に設定されればよ レ^ エーテルには例えばジォクチルェ一テルが含まれる。  In forming the nanoparticles, a specific organic solvent is prepared. As the organic solvent, aprotic organic solvents such as hydrocarbons, ethers and esters can be used. In such an organic solvent, if the number of carbon atoms is set to 2 to 20, the ether includes, for example, dioctyl ether.
同様に、 ナノ粒子の形成にあたって非プロトン性の有機溶媒に溶け難い還元剤 が用意される。 還元剤には例えば 1,2-ジオールが用いられることができる。 1,2- ジオールでは炭素数は 2〜 6の範囲で設定されればよい。 こういった 1,2-ジォ一 ルには例えば 1 ,2-ブタンジオールが挙げられる。  Similarly, a reducing agent that is difficult to dissolve in an aprotic organic solvent for forming nanoparticles is prepared. For example, 1,2-diol can be used as the reducing agent. For 1,2-diol, the number of carbon atoms may be set in the range of 2 to 6. Such 1,2-diols include, for example, 1,2-butanediol.
さらに、 ナノ粒子の形成にあたって特定の有機安定剤が用意される。 有機安定 剤は例えばカルボン酸 R— COOHを含む。 こういったカルボン酸中の Rは、 二 重結合を含む直鎖型炭化水素基から選択されればよい。 こういった直鎖型炭化水 素基は例えば C12H23、 C17H33ぉょびC21H41のぃずれかから選択されれば よい。 その他、 有機安定剤は例えばァミン R— NH2を含んでもよい。 こういつ たァミン中の Rは、 同様に、 二重結合を含む直鎖型炭化水素基から選択されれば よい。 こういった直鎖型炭化水素基は例えば C13H25、 C18H35および C22H 43のいずれかから選択されればよい。 有機安定剤はカルボン酸 R— COOHお よびアミン R— N H 2のいずれか一方を含んでもよく両者を含んでもよい。 In addition, certain organic stabilizers are provided for nanoparticle formation. Organic stabilizers include, for example, the carboxylic acid R-COOH. R in such a carboxylic acid may be selected from a linear hydrocarbon group containing a double bond. Such a linear hydrocarbon group may be selected from, for example, any one of C 12 H 23 , C 17 H 33 and C 21 H 41 . In addition, the organic stabilizer may include, for example, amine R—NH 2 . R in such an amine may be similarly selected from a linear hydrocarbon group containing a double bond. Such a linear hydrocarbon group may be selected, for example, from any of C 13 H 25 , C 18 H 35 and C 22 H 43 . The organic stabilizer may include one or both of the carboxylic acid R—COOH and the amine R—NH 2 .
ナノ粒子の形成にあたって例えば窒素ガスやアルゴンガスといった不活性ガス 雰囲気下でフラスコは用意される。 フラスコ内では、 前述の金属化合物、 有機溶 媒、 還元剤および有機安定剤とが混合されて溶液が生成される。 こうしてフラス コ内で生成される溶液は所定の反応温度下で撹拌される。 反応温度は例えば 10 0°C〜300 の範囲で設定される。 その結果、 溶液内では還元剤に基づき金属 化合物から金属が還元される。 こうしてナノ粒子は形成される。 ナノ粒子はォレ ィン酸ゃォレイルァミンといつた有機安定剤に包まれる。 その後、 フラスコ内の溶液は室温まで冷却される。 フラスコ内にはエタノール といった溶剤が加えられる。 遠心分離に基づきナノ粒子および有機安定剤の沈殿 物が取り出される。 取り出されたナノ粒子および有機安定剤はへキサンといった 有機溶剤に投入される。 こうしてへキサン溶液中に分散するナノ粒子は得られる。 以上のような製造方法によれば、 還元剤の 1,2-ジォ一ルは炭化水素やエーテル、 エステルといった非プロトン性有機溶媒に溶け難いことから、 還元剤と有機溶媒 とは相分離されることができる。 溶液の極性は低く保持される結果、 ナノ粒子の 凝集は十分に阻止されることができる。 比較的に簡単に微細かつ均一なナノ粒子 は形成されることができる。 For the formation of the nanoparticles, the flask is prepared in an atmosphere of an inert gas such as nitrogen gas or argon gas. In the flask, the above-mentioned metal compound, organic solvent, reducing agent and organic stabilizer are mixed to form a solution. The solution thus formed in the flask is stirred at a predetermined reaction temperature. The reaction temperature is set, for example, in the range of 100 ° C to 300 ° C. As a result, the metal is reduced from the metal compound in the solution based on the reducing agent. Thus, nanoparticles are formed. The nanoparticles are encapsulated in organic stabilizers such as oleylamine phosphate. Thereafter, the solution in the flask is cooled to room temperature. A solvent such as ethanol is added into the flask. The precipitate of nanoparticles and organic stabilizer is removed based on centrifugation. The extracted nanoparticles and organic stabilizer are put into an organic solvent such as hexane. Thus, nanoparticles dispersed in the hexane solution are obtained. According to the above-described production method, the reducing agent 1,2-diol is hardly soluble in aprotic organic solvents such as hydrocarbons, ethers, and esters, so that the reducing agent and the organic solvent are phase-separated. Can be As a result of keeping the polarity of the solution low, aggregation of the nanoparticles can be sufficiently prevented. Fine and uniform nanoparticles can be formed relatively easily.
本発明者は、 前述の製造方法に基づき鉄白金 (FeP t) ナノ粒子を製造した。 アルゴンガス雰囲気下でフラスコは用意された。 フラスコ内には、 金属化合物す なわち 197mg (0. 5mM相当) の白金 (I I) ァセチルァセトナトと、 1 77mg (0. 5mM相当) の鉄 (I I I) ァセチルァセトナトとが配置された。 フラスコには、 1 OmLの有機溶剤すなわちジォクチルエーテルが加えられた。 同様に、 フラスコには、 0. 9 lmLの還元剤すなわち 1,2-ブタンジオールが加 えられた。 同様に、 フラスコに、 有機安定剤すなわち 0. 16mL (0. 05m M相当) のォレイン酸と 0. 17mL (0. 5mM相当) のォレイルァミンとが 加えられた。  The present inventors manufactured iron platinum (FePt) nanoparticles based on the above-described manufacturing method. The flask was prepared under an argon gas atmosphere. In the flask, a metal compound, ie, 197 mg (0.5 mM equivalent) of platinum (II) acetyl acetate and 177 mg (0.5 mM equivalent) of iron (III) acetyl acetate were placed. Was done. To the flask was added 1 OmL of an organic solvent, octyl ether. Similarly, the flask was charged with 0.9 mL of the reducing agent, ie, 1,2-butanediol. Similarly, an organic stabilizer, 0.16 mL (equivalent to 0.05 mM) of oleic acid and 0.17 mL (equivalent to 0.5 mM) of oleylamine were added to the flask.
こうしてフラスコ内で生成された溶液は 190°Cの温度下で 30分間撹拌され た。 その後、 フラスコ内の溶液は室温まで冷却された。 フラスコ内には 1 OmL のエタノールが加えられた。 遠心分離に基づきナノ粒子および有機安定剤の沈殿 物が取り出された。 取り出されたナノ粒子および有機安定剤はへキサン溶液に投 入された。 こうしてへキサン溶液中に分散する FeP tナノ粒子は得られた。 本発明者は、 以上のように形成した FeP tナノ粒子を検証した。 その結果、 FeP tナノ粒子の平均粒径は 2. 9 nm程度であることが確認された。 すなわ ち、 非常に微細で均一なナノ粒子が形成されることが確認された。 FeP tナノ 粒子では、 組成比 F e : P tは 45 : 55 [%] であることが確認された。  The solution thus formed in the flask was stirred at a temperature of 190 ° C for 30 minutes. Thereafter, the solution in the flask was cooled to room temperature. 1 OmL of ethanol was added to the flask. The precipitate of nanoparticles and organic stabilizer was removed based on centrifugation. The extracted nanoparticles and organic stabilizer were injected into a hexane solution. Thus, FePt nanoparticles dispersed in the hexane solution were obtained. The present inventors have verified the FePt nanoparticles formed as described above. As a result, it was confirmed that the average particle size of the FePt nanoparticles was about 2.9 nm. That is, it was confirmed that very fine and uniform nanoparticles were formed. It was confirmed that the composition ratio Fe: Pt of the FePt nanoparticles was 45:55 [%].
次に本発明者は金属化合物の使用量とナノ粒子の組成比との関係を検証した。 ナノ粒子の製造にあたって、 前述と同様に、 金属化合物には白金 (I I) ァセチ ルァセトナトと鉄 (I I I) ァセチルァセトナトとが用いられた。 この検証では 本発明者は各金属化合物の使用量を変化させた。 図 15に示されるように、 Fe P tナノ粒子の組成比は白金 (I I) ァセチルァセトナトの使用量と鉄 (I I I) ァセチルァセトナトの使用量との比を反映することが確認された。 すなわち、 前述の製造方法によれば、 金属化合物の使用量に基づきナノ粒子中の金属の組成 比は制御されることができる。 Next, the present inventors examined the relationship between the amount of the metal compound used and the composition ratio of the nanoparticles. In the production of nanoparticles, as described above, platinum (II) acetate Ruacetonato and iron (III) acetilacetonato were used. In this verification, the inventor changed the amount of each metal compound used. As shown in Figure 15, the composition ratio of Fe Pt nanoparticles can reflect the ratio of the amount of platinum (II) acetyl acetonato used to the amount of iron (III) acetyl acetonato used. confirmed. That is, according to the above-described production method, the composition ratio of the metal in the nanoparticles can be controlled based on the amount of the metal compound used.
本発明者の検証によれば、 前述の白金 (I I) ァセチルァセトナトは、 酢酸白 金 (I I) や安息香酸白金 (1 1)、 シアン化白金 (1 1)、 ベンゼンスルホン酸 白金 (I 1)、 プロピルホスホン酸白金 (1 1)、 臭化白金 (1 1)、 ヨウ化白金 (I I) に置き換えられることが確認された。 同様に、 鉄 (I I I) ァセチルァ セトナトは、 酢酸鉄 (I I I) や安息香酸鉄 (1 1 1)、 シアン化鉄 (1 1 1)、 ベンゼンスルホン酸鉄 (I I 1)、 プロピルホスホン酸鉄 (I I 1)、 臭ィ匕鉄 (I I 1)、 ヨウ化鉄 (I I 1)、 鉄 (I I) ァセチルァセトナト、 酢酸鉄 (1 1)、 安息香酸鉄 (1 1)、 シアン化鉄 (1 1)、 ベンゼンスルホン酸鉄 (1 1)、 プロ ピルホスホン酸鉄 (1 1)、 臭化鉄 (I I) に置き換えられることが確認された。 しかも、 本発明者の検証によれば、 1,2-ブタンジオールは、 2、 3、 5および 6 のいずれかの炭素数を有する 1,2-ジオールに置き換えられることが確認された。 さらに、 本発明者は、 白金 (I I) ァセチルァセトナト、 鉄 (I I I) ァセチ ルァセトナトおよびビスァセチルァセトナト銅 (I I) に基づき前述の製造方法 に従ってナノ粒子を製造した。 その結果、 平均粒径 2. 7nm〜3. 5 nmの白 金鉄銅 (FeP t Cu) ナノ粒子が得られた。 白金鉄銅ナノ粒子の組成比は各金 属化合物の使用量を反映することが確認された。  According to the verification of the present inventor, the above-mentioned platinum (II) acetyl acetonate is composed of platinum (II) acetate, platinum benzoate (11), platinum cyanide (11), platinum benzenesulfonate ( I 1), platinum propylphosphonate (1 1), platinum bromide (1 1), and platinum iodide (II) were confirmed to be replaced. Similarly, iron (III) acetyla settonate is composed of iron (III) acetate, iron benzoate (111), iron cyanide (111), iron benzenesulfonate (II1), iron propylphosphonate (II). 1), odori iron (II 1), iron iodide (II 1), iron (II) acetyl acetonato, iron acetate (1 1), iron benzoate (1 1), iron cyanide (1 1), iron benzenesulfonate (11), iron propylphosphonate (11), and iron bromide (II) were confirmed to be replaced. Moreover, according to the verification of the present inventors, it was confirmed that 1,2-butanediol can be replaced by 1,2-diol having any one of 2, 3, 5, and 6 carbon atoms. Furthermore, the present inventors produced nanoparticles based on platinum (II) acetyl acetonato, iron (III) acetyl acetonato and bis (acetyl acetonato copper) according to the above-mentioned production method. As a result, white gold-iron-copper (FePtCu) nanoparticles with an average particle size of 2.7 nm to 3.5 nm were obtained. It was confirmed that the composition ratio of the platinum-iron-copper nanoparticles reflects the amount of each metal compound used.
本発明者は、 白金 (I I) ァセチルァセトナト、 鉄 (I I I) ァセチルァセト ナトおよび酢酸銀 (I) に基づき前述の製造方法に従ってナノ粒子を製造した。 その結果、 平均粒径 2. 6nm〜3. 4 nmの白金鉄銀 (P t FeAg) ナノ粒 子が得られた。 白金鉄銀ナノ粒子の組成比は各金属化合物の使用量を反映するこ とが確認された。  The present inventors produced nanoparticles based on platinum (II) acetyl acetonato, iron (III) acetyl acetonato and silver (I) acetate according to the above-mentioned production method. As a result, platinum-iron-silver (PtFeAg) nanoparticles with an average particle size of 2.6 nm to 3.4 nm were obtained. It was confirmed that the composition ratio of platinum iron silver nanoparticles reflects the amount of each metal compound used.
さらにまた、 本発明者は前述の製造方法に基づきナノ粒子を製造した。 製造に あたって、 金属化合物には、 前述の白金 (I I) ァセチルァセトナトおよび鉄 (I I I) ァセチルァセトナトに加え、 コバルト (I) ァセチルァセトナトゃク ロム (I I I) ァセチルァセトナト、 ニッケル (I I) ァセチルァセトナト、 マ ンガン (I I) ァセチルァセトナト、 鉛 (I I) ァセチルァセトナトのいずれか が用いられた。 その結果、 平均粒径 2. 6nm〜3. 6nmの FeP t Coナノ 粒子や F e P t C rナノ粒子、 FeP tN iナノ粒子、 FeP tMnナノ粒子、 F e P t P bナノ粒子が得られた。 こういったナノ粒子の組成比は各金属化合物 の使用量を反映することが確認された。 Furthermore, the inventor produced nanoparticles based on the above-mentioned production method. In the production, the metal compounds include platinum (II) acetylacetonato and iron (III) In addition to acetyl acetonato, cobalt (I) acetyl acetonatochrome (III) acetyl acetonato, nickel (II) acetyl acetonato, mangan (II) acetyla Either setnat or lead (II) acetyl acetonato was used. As a result, FePtCo nanoparticles, FePtCr nanoparticles, FePtNi nanoparticles, FePtMn nanoparticles, and FePtPb nanoparticles with average particle sizes of 2.6 nm to 3.6 nm were obtained. Was done. It was confirmed that the composition ratio of these nanoparticles reflects the amount of each metal compound used.

Claims

請求の範囲 The scope of the claims
1 . 基体と、 基体の表面に穿たれる微小ホール内に配置される微小粒子とを備え ることを特徴とする複合材。 1. A composite material comprising: a base; and microparticles arranged in microholes formed in the surface of the base.
2 . 請求の範囲第 1項に記載の複合材において、 前記基体の表面に積層されて、 微小ホール内に微小粒子を閉じ込める被覆層をさらに備えることを特徴とする複 合材。 2. The composite material according to claim 1, further comprising: a coating layer laminated on a surface of the base to confine the fine particles in the fine holes.
3 . 請求の範囲第 1項または第 2項に記載の複合材において、 前記基体および微 小粒子のうち一方は磁性体から構成され、 他方は非磁性体から構成されることを 特徴とする複合材。 3. The composite material according to claim 1 or 2, wherein one of the substrate and the fine particles is made of a magnetic material, and the other is made of a non-magnetic material. Wood.
4. 請求の範囲第 1項または第 2項に記載の複合材において、 前記基体および微 小粒子のうち一方は導電体から構成され、 他方は絶縁体から構成されることを特 徵とする複合材。 4. The composite material according to claim 1, wherein one of the substrate and the fine particles is formed of a conductor, and the other is formed of an insulator. Wood.
5 . 表面に穿たれる微小ホールを有する基体を用意する工程と、 基体の表面に、 特定の溶媒中に微小粒子を含む液体を塗布する工程と、 微小ホールから基体の表 面に溢れる微小粒子を拭い去る工程とを備えることを特徴とする複合材の製造方 法。 5. A step of preparing a substrate having fine holes drilled in the surface, a step of applying a liquid containing fine particles in a specific solvent to the surface of the substrate, and fine particles overflowing from the fine holes to the surface of the substrate And a step of wiping off the composite material.
6 . 請求の範囲第 5項に記載の複合材の製造方法において、 前記微小粒子を含む 液体の塗布にあたってスピンコート法またはディップ法が実施されることを特徴 とする複合材の製造方法。 6. The method for producing a composite material according to claim 5, wherein a spin coating method or a dip method is performed when applying the liquid containing the fine particles.
7 . 請求の範囲第 5項または第 6項に記載の複合材の製造方法において、 前記基 体および微小粒子のうち一方は磁性体から構成され、 他方は非磁性体から構成さ れることを特徴とする複合材の製造方法。 7. The method for producing a composite material according to claim 5 or 6, wherein one of the substrate and the fine particles is made of a magnetic material, and the other is made of a non-magnetic material. The method of manufacturing a composite material.
8 . 微小粒子の集合体と、 微小粒子同士の間に存在する炭素原子とを備え、 微小 粒子を構成する原子の原子数および炭素原子の原子数の総計に対して炭素原子単 独の原子数は 4 5原子%〜9 6原子%の範囲に設定されることを特徴とする構造 体。 8. It has an aggregate of microparticles and carbon atoms existing between the microparticles, and the number of atoms of carbon atoms alone with respect to the number of atoms constituting the microparticles and the total number of carbon atoms Is a structure characterized by being set in the range of 45 atomic% to 96 atomic%.
9 . 請求の範囲第 8項に記載の構造体において、 前記微小粒子の直径は 1 nm〜 3 0 n mの範囲で設定されることを特徴とする構造体。 9. The structure according to claim 8, wherein the diameter of the fine particles is set in a range of 1 nm to 30 nm.
1 0 . 請求の範囲第 8項または第 9項に記載の構造体において、 前記微小粒子は 結晶粒を含むことを特徴とする構造体。 10. The structure according to claim 8 or 9, wherein the fine particles include crystal grains.
1 1 . 対象物の表面に、 有機化合物で包まれる微小金属粒子を含む有機溶剤を塗 布する工程と、 有機溶剤の乾燥後に、 真空環境下で微小金属粒子にァニール処理 を施す工程とを備え、 微小金属粒子を構成する原子の原子数と有機化合物中の炭 素原子の原子数との総計に対して有機化合物中の炭素原子の原子数は 4 5原子% 〜 9 6原子%の範囲に設定されることを特徴とする構造体の製造方法。 1 1. A step of applying an organic solvent containing fine metal particles wrapped with an organic compound to the surface of an object, and a step of subjecting the fine metal particles to an annealing treatment in a vacuum environment after drying the organic solvent. The number of carbon atoms in the organic compound is in the range of 45 to 96 atomic% with respect to the sum of the number of atoms constituting the fine metal particles and the number of carbon atoms in the organic compound. A method of manufacturing a structure, wherein the method is set.
1 2 . 請求の範囲第 1 1項に記載の構造体の製造方法において、 前記ァニール処 理の実施に先立って、 不活性ガス雰囲気下で有機化合物に加熱処理を施す工程を さらに備えることを特徴とする構造体の製造方法。 12. The method for manufacturing a structure according to claim 11, further comprising a step of subjecting the organic compound to a heat treatment in an inert gas atmosphere prior to the execution of the annealing treatment. Manufacturing method of the structure.
1 3 . 基層と、 基層の表面に配置される微小粒子と、 微小粒子に基づき成長する 結晶粒を含む結晶層とを備えることを特徴とする多結晶構造膜。 13. A polycrystalline structure film comprising: a base layer; fine particles arranged on the surface of the base layer; and a crystal layer including crystal grains that grow based on the fine particles.
1 4. 請求の範囲第 1 3項に記載の多結晶構造膜において、 前記微小粒子は金属 元素を含むことを特徴とする多結晶構造膜。 14. The polycrystalline structure film according to claim 13, wherein the fine particles include a metal element.
1 5 . 請求の範囲第 1 3項または第 1 4項 に記載の多結晶構造膜において、 前 記微小粒子は、 前記基層の表面に途切れなく広がる連続層を形成することを特徴 とする多結晶構造膜。 15. The polycrystalline structure film according to claim 13 or claim 14, wherein The polycrystalline structure film, wherein the microparticles form a continuous layer that extends continuously on the surface of the base layer.
1 6 . 微小粒子に基づき成長する結晶粒で構成される下地多結晶層と、 下地多 晶層の個々の結晶粒から成長する結晶粒で構成される磁性多結晶層とを備えるこ とを特徴とする磁気記録媒体。 16. It is characterized by comprising an underlying polycrystalline layer composed of crystal grains grown based on fine particles and a magnetic polycrystalline layer composed of crystal grains grown from individual crystal grains of the underlying polycrystalline layer. Magnetic recording medium.
1 7 . 請求の範囲第 1 6項に記載の磁気記録媒体において、 前記微小粒子は金属 元素を含むことを特徴とする磁気記録媒体。 17. The magnetic recording medium according to claim 16, wherein the fine particles include a metal element.
1 8 . 微小粒子に基づき成長する結晶粒で構成される磁性多結晶層を備えること を特徴とする磁気記録媒体。 18. A magnetic recording medium comprising a magnetic polycrystalline layer composed of crystal grains grown based on fine particles.
1 9 . 請求の範囲第 1 8項に記載の磁気記録媒体において、 非磁性層で前記磁性 多結晶層から隔てられる軟磁性の裏打ち層をさらに備えることを特徴とする磁気 記録媒体。 19. The magnetic recording medium according to claim 18, further comprising a soft magnetic underlayer separated from the magnetic polycrystalline layer by a nonmagnetic layer.
2 0 . 請求の範囲第 1 8項または第 1 9項に記載の磁気記録媒体において、 前記 微小粒子は金属元素を含むことを特徴とする磁気記録媒体。 20. The magnetic recording medium according to claim 18, wherein the microparticles include a metal element.
2 1 . 有機溶媒中に、 有機溶媒に対して難溶を示す還元剤、 金属化合物および有 機安定剤を含む溶液を生成する工程と、 所定の反応温度下で獰液を撹拌する工程 とを備えることを特徴とする微小粒子の製造方法。 21. A step of forming a solution containing a reducing agent, a metal compound, and an organic stabilizer that is hardly soluble in the organic solvent in the organic solvent, and a step of stirring the fertile liquid at a predetermined reaction temperature. A method for producing fine particles, comprising:
2 2 . 請求の範囲第 2 1項に記載の微小粒子の製造方法において、 前記溶液は 2 種類以上の前記金属化合物を含むことを特徴とする微小粒子の製造方法。 22. The method for producing fine particles according to claim 21, wherein the solution contains two or more kinds of the metal compounds.
2 3 . 請求の範囲第 2 1項または第 2 2項に記載の微小粒子の製造方法において、 前記有機溶媒は炭素数 6〜 2 0の非プロトン性有機溶媒で構成されることを特徴 とする微小粒子の製造方法。 23. The method for producing fine particles according to claim 21 or 22, wherein the organic solvent comprises an aprotic organic solvent having 6 to 20 carbon atoms. A method for producing fine particles.
2 4. 請求の範囲第 2 1項〜第 2 3項のいずれかに記載の微小粒子の製造方法に おいて、 前記還元剤は炭素数 2〜6の 1 ,2-ジオールであることを特徴とする微小 粒子の製造方法。 2 4. The method for producing microparticles according to any one of claims 21 to 23, wherein the reducing agent is a 1,2-diol having 2 to 6 carbon atoms. A method for producing fine particles.
2 5 . 請求の範囲第 2 1項〜第 2 4項のいずれかに記載の微小粒子の製造方法に おいて、 前記有機安定剤はカルボン酸 R— C O OHを含むことを特徴とする微小 粒子の製造方法。 25. The method for producing fine particles according to any one of claims 21 to 24, wherein the organic stabilizer comprises a carboxylic acid R-COOH. Manufacturing method.
2 6 . 請求の範囲第 2 1項〜第 2 5項のいずれかに記載の微小粒子の製造方法に おいて、 前記有機安定剤はァミン R— NH 2を含むことを特徴とする微小粒子の 製造方法。 2 6. Oite the method for producing microparticles according to any one of the second items 1 to 2 Item 5 claims, wherein the organic stabilizer of fine particles comprising the Amin R- NH 2 Production method.
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