WO2013187217A1 - MAGNETIC RECORDING MEDIUM USING FERROMAGNETIC-PARAMAGNETIC PHASE TRANSITION IN FePt ALLOY - Google Patents

MAGNETIC RECORDING MEDIUM USING FERROMAGNETIC-PARAMAGNETIC PHASE TRANSITION IN FePt ALLOY Download PDF

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Publication number
WO2013187217A1
WO2013187217A1 PCT/JP2013/064634 JP2013064634W WO2013187217A1 WO 2013187217 A1 WO2013187217 A1 WO 2013187217A1 JP 2013064634 W JP2013064634 W JP 2013064634W WO 2013187217 A1 WO2013187217 A1 WO 2013187217A1
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Prior art keywords
magnetic recording
alloy
recording medium
thin film
ferromagnetic
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PCT/JP2013/064634
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French (fr)
Japanese (ja)
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長谷川　崇
俊二 石尾
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国立大学法人秋田大学
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Priority to JP2014521245A priority Critical patent/JP6296243B2/en
Publication of WO2013187217A1 publication Critical patent/WO2013187217A1/en

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    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/62—Record carriers characterised by the selection of the material
    • G11B5/64—Record carriers characterised by the selection of the material comprising only the magnetic material without bonding agent
    • G11B5/65—Record carriers characterised by the selection of the material comprising only the magnetic material without bonding agent characterised by its composition
    • G11B5/658—Record carriers characterised by the selection of the material comprising only the magnetic material without bonding agent characterised by its composition containing oxygen, e.g. molecular oxygen or magnetic oxide
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/84—Processes or apparatus specially adapted for manufacturing record carriers
    • G11B5/855—Coating only part of a support with a magnetic layer
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F10/00—Thin magnetic films, e.g. of one-domain structure
    • H01F10/08—Thin magnetic films, e.g. of one-domain structure characterised by magnetic layers
    • H01F10/10—Thin magnetic films, e.g. of one-domain structure characterised by magnetic layers characterised by the composition
    • H01F10/12—Thin magnetic films, e.g. of one-domain structure characterised by magnetic layers characterised by the composition being metals or alloys
    • H01F10/123—Thin magnetic films, e.g. of one-domain structure characterised by magnetic layers characterised by the composition being metals or alloys having a L10 crystallographic structure, e.g. [Co,Fe][Pt,Pd] thin films
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F41/00—Apparatus 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
    • H01F41/32—Apparatus 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 conductive, insulating or magnetic material on a magnetic film, specially adapted for a thin magnetic film
    • H01F41/34—Apparatus 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 conductive, insulating or magnetic material on a magnetic film, specially adapted for a thin magnetic film in patterns, e.g. by lithography

Definitions

  • the present invention relates to a magnetic recording medium having a magnetic recording layer in which a ferromagnetic material and a non-magnetic material are arranged according to a predetermined rule, a method for manufacturing the magnetic recording medium, and a magnetic recording device including the magnetic recording medium.
  • a hard disk drive which is a magnetic recording device, includes a disk-shaped hard disk as a magnetic recording medium capable of recording data.
  • the hard disk drive also includes a drive device such as a rotating shaft and a motor for rotating the hard disk at high speed. By rotating the hard disk at high speed with this drive device and moving the magnetic head on the hard disk, information can be recorded on or read from the magnetic recording layer provided in the hard disk.
  • the recording bit is composed of a material having a strong characteristic against thermal fluctuation, that is, a ferromagnetic material having high perpendicular magnetic anisotropy.
  • FePt alloy having an L1 0 ordered structure As the material capable of realizing a super high density magnetic recording medium of the surface recording density of several terabits / square inch, FePt alloy having an L1 0 ordered structure is expected. Since the FePt alloy having the L1 0 ordered structure has strong characteristics against thermal fluctuation, it is expected to realize an ultra-high density magnetic recording medium in which a recording bit is formed using this.
  • the “L1 0 ordered structure” is a structure in which two types of atoms are alternately stacked in an fct structure and the composition ratio of the two types of atoms is 1: 1.
  • Non-Patent Document 1 As a method for manufacturing a thin film by FePt alloy having an L1 0 ordered structure, for example, it is disclosed in the following Non-Patent Document 1. According to the technique described in Non-Patent Document 1, a FePt alloy thin film having high [001] orientation and high L1 0 order by adding a predetermined amount of SiO 2 to a FePt alloy thin film and rapidly heating it. Can be obtained.
  • Non-Patent Documents 2 and 3 below describe the technology related to the bulk of the FeMnPt alloy in which the Fe atom site of the FePt alloy is replaced with Mn, and the following Non-Patent Document 4 describes the technology related to the polycrystalline thin film of the FeMnPt alloy. Has been.
  • bit patterned media (hereinafter sometimes abbreviated as “BPM”) has attracted attention as a recording method for realizing an ultra-high density magnetic recording medium.
  • BPM is a magnetic recording medium having a structure in which nanoscale ferromagnetic materials (dots) are two-dimensionally arranged in a nonmagnetic material according to a predetermined rule.
  • a so-called top-down method is generally used as a method for producing such BPM. That is, a ferromagnetic thin film is first formed on a substrate, a mask is placed on the thin film, and the thin film is milled only at a portion where a nonmagnetic material is to be placed. In this method, a nonmagnetic material is deposited and backfilled, and then the surface is polished. In this method, since it is necessary to recover the damage received by the ferromagnetic material by milling or surface polishing, it is necessary to finally perform heat treatment.
  • Patent Document 1 As another manufacturing method of BPM, as described in Patent Document 1 below, after forming a thin film on a substrate with either a ferromagnetic material or an antiferromagnetic material, ion implantation or additive elements are performed. A method is also conceivable in which a predetermined region of the formed thin film is modified to the other of a ferromagnetic material or an antiferromagnetic material by adjusting the composition by diffusing. As a method of modifying the magnetic material, there is a method of changing the crystal structure by irradiating ions as described in Non-Patent Documents 5 and 6 below.
  • non-patent document 7 is a Co / Pd multilayer film
  • non-patent document 8 is a CrPt 3 ordered alloy thin film
  • non-patent document 9 is MnBiCu.
  • Thin Film Non-Patent Document 10 describes a MnAl thin film.
  • the top-down method is generally used to produce a magnetic recording medium in which a ferromagnetic material such as BPM and a non-magnetic material are two-dimensionally arranged according to a predetermined rule.
  • the top-down method has steps S21 to S27 as shown in FIG.
  • FIG. 5 is a flowchart for explaining a manufacturing method S20 of the magnetic recording medium by the top-down method.
  • FIG. 6 is a cross-sectional view illustrating the manufacturing method S20.
  • the film forming step S21 is a step of forming a ferromagnetic thin film 22 ′ on the substrate 21 as shown in FIG.
  • Film forming step S21 is, for example, a step of forming a thin film 22 'of the FePt alloy having an L1 0 ordered structure.
  • the mask arrangement step S22 is performed on the thin film 22 ′ so that only the portion where the non-ferromagnetic material is to be arranged can be milled out of the thin film 22 ′ formed in the film formation step S21.
  • the mask 25 is disposed on the substrate. As shown in FIG.
  • the milling step S23 is a step of milling only the planned portion 26 where the non-ferromagnetic material is arranged in the thin film 22 ′ formed in the film forming step S21.
  • the milling step S23 is a step of finely processing the thin film 22 ′ into a bit pattern by, for example, ion milling (ion irradiation amount 100 at%).
  • the mask removal step S24 is a step of removing the mask 25 arranged in the mask arrangement step S22 as shown in FIG.
  • the backfill film forming step S25 is a step in which the non-ferromagnetic material 27 is formed and the portion 26 milled in the milling step S23 is backfilled with the nonferromagnetic material 27. .
  • the surface polishing step S26 as shown in FIG. 6 (F), the surface of the thin film having ferromagnetic and non-ferromagnetic materials obtained through steps S21 to S25 is polished, and the surface of the thin film is flattened. It is a process to convert.
  • the heat treatment step S27 is a step of performing a heat treatment on the thin film obtained through the steps S21 to S26. Since the L1 0 ordered structure is weak against ion milling and surface polishing, it is necessary to recover the damage received by the L1 0 ordered structure by heat treatment.
  • the heat treatment step S27 it is necessary to perform the heat treatment step S27.
  • the heat treatment always involves atomic interdiffusion, the non-ferromagnetic material 27 formed in the backfill film forming step S25 and the FePt alloy constituting the thin film 22 ′ are mixed, and finally the ferromagnetic part There was a risk of deteriorating magnetic properties.
  • the number of steps increases, so the manufacturing cost of the magnetic recording medium tends to increase, and the process of polishing the surface tends to reduce the product quality and yield.
  • a method of producing BPM by irradiating ions without using the top-down method has been considered.
  • a magnetic material conventionally applied to such a method is an ultra-high density.
  • the magnetic anisotropy was insufficient for application to a magnetic recording medium. That is, it is difficult to sufficiently increase the recording density of the magnetic recording medium with the conventional BPM manufacturing method that does not depend on the top-down method.
  • the present inventors have found that an alloy obtained by substituting a predetermined amount of Fe or Pt of a FePt alloy with a predetermined element undergoes a magnetic phase change that has not been known so far. That is, the alloy obtained by replacing a predetermined amount of a part of Fe or Pt to a predetermined element of the FePt alloy, with may be a hard ferromagnetic material having an L1 0 ordered structure, is irradiated with any ion Thus, it has been found that a paramagnetic material having an A1 irregular structure can be obtained. The present invention has been made based on this finding.
  • a first aspect of the present invention includes a base material layer and a magnetic recording layer formed on the base material layer, and the magnetic recording layer includes a ferromagnetic portion and a paramagnetic portion arranged according to a predetermined rule.
  • the ferromagnetic part includes an alloy having ferromagnetism with a saturation magnetization of 0.37 [Wb / m 2 ] or more and 1.38 [Wb / m 2 ] or less, and the paramagnetic part has a saturation magnetization of An alloy having a paramagnetism of 0 [Wb / m 2 ] or more and 0.88 [Wb / m 2 ] or less is included, and the saturation magnetization of the alloy included in the ferromagnetic portion and the saturation of the alloy included in the paramagnetic portion The difference from the magnetization is 0.10 [Wb / m 2 ] or more, and the alloy contained in the ferromagnetic part and the alloy contained in the paramagnetic part have substantially the same composition,
  • M 1 is Mn or Nb
  • x is a saturation magnetization in the L1 0 ordered structure of 0.37 [Wb / m 2 ] or more and 1.38 [Wb / m 2 ].
  • the saturation magnetization in the A1 irregular structure is 0 [Wb / m 2 ] or more and 0.88 [Wb / m 2 ] or less, and the difference between the saturation magnetizations is 0.10 [Wb / m 2 ] or more.
  • Fe (Pt 1-y M 2 y ) (2) (However, in the above formula (2), M 2 is any one of Ru, Rh, Os, and Ir, and y is a saturation magnetization in the L1 0 ordered structure of 0.37 [Wb / m 2 ] or more 1 .38 [Wb / m 2 ] or less, the saturation magnetization in the A1 disordered structure is 0 [Wb / m 2 ] or more and 0.88 [Wb / m 2 ] or less, and the difference between the saturation magnetizations is 0.10. (Wb / m 2 ] or more.)
  • “having a magnetic recording layer formed on a base material layer” is not limited to the form in which the magnetic recording layer is directly laminated on the base material layer, and the base material is interposed via another layer. It is a concept including a form in which a layer and a magnetic recording layer are laminated.
  • the “predetermined rule” of the “ferromagnetic part and paramagnetic part arranged according to a predetermined rule” is a ferromagnetic material in a conventional BPM or discrete track media (hereinafter, also referred to as “DTM”). And the same rule as the arrangement rule of the non-magnetic material.
  • the alloy contained in the ferromagnetic part and the alloy contained in the paramagnetic part have substantially the same composition
  • the composition of the alloy contained in the ferromagnetic part and the composition of the alloy contained in the paramagnetic part are It is not limited to exactly the same, and when ions are irradiated as described later in the process of manufacturing the magnetic recording layer, the ions remain and the composition of the alloy contained in the ferromagnetic part and the paramagnetic part It is a concept that includes a form slightly different from the composition of the contained alloy, and specifically means that it is the same at 97 at% or more.
  • the composition of the alloy contained in the ferromagnetic portion and the alloy contained in the paramagnetic portion is (Fe 1-x Mn x ) Pt. ⁇ X ⁇ 0.54.
  • the magnetic recording layer preferably contains a metal oxide.
  • the (001) plane of the crystal constituting the alloy contained in the magnetic recording layer is parallel to the surface of the magnetic recording layer, and [001] The direction is preferably perpendicular to the surface of the magnetic recording layer.
  • a second aspect of the present invention is a ferromagnetic part and a paramagnetic part having a base material layer and a magnetic recording layer formed on the base material layer, wherein the magnetic recording layer is arranged according to a predetermined rule.
  • a method for manufacturing a magnetic recording medium having a, a base layer, a composition which has an L1 0 ordered structure is represented by the following formula (1) or (2), and the saturation magnetization is 0.37
  • a method for manufacturing a magnetic recording medium having a, a base layer, a composition which has an L1 0 ordered structure is represented by the following formula (1) or (2), and the saturation magnetization is 0.37
  • a method for manufacturing a magnetic recording medium having a, a base layer, a composition which has an L1 0 ordered structure is represented by the following formula (1) or (2), and the saturation magnetization is 0.37
  • the method of manufacturing a magnetic recording medium is such that a portion not irradiated with ions becomes a ferromagnetic portion.
  • M 1 is Mn or Nb
  • x is a saturation magnetization in the L1 0 ordered structure of 0.37 [Wb / m 2 ] or more and 1.38 [Wb / m 2 ].
  • the saturation magnetization in the A1 irregular structure is 0 [Wb / m 2 ] or more and 0.88 [Wb / m 2 ] or less, and the difference between the saturation magnetizations is 0.10 [Wb / m 2 ] or more.
  • Fe (Pt 1-y M 2 y ) (2) (However, in the above formula (2), M 2 is any one of Ru, Rh, Os, and Ir, and y is a saturation magnetization in the L1 0 ordered structure of 0.37 [Wb / m 2 ] or more 1 .38 [Wb / m 2 ] or less, the saturation magnetization in the A1 disordered structure is 0 [Wb / m 2 ] or more and 0.88 [Wb / m 2 ] or less, and the difference between the saturation magnetizations is 0.10. (It is a value that is equal to or greater than [Wb / m 2 ].)
  • ions used in the ion irradiation step are Mn ions, and the irradiation amount of the Mn ions is 0.10 at% of the portion where the paramagnetic part is formed. It is preferably 2.0 at% or less.
  • the thin film forming step includes an alloy having a composition represented by the above formula (1) or (2) and a metal oxide. It is preferable to include a step of heating the thin film after forming the thin film.
  • a magnetic recording medium according to the first aspect of the present invention, a rotating shaft and a motor that rotates the magnetic recording medium, information is recorded on the magnetic recording layer, and / or Alternatively, the magnetic recording apparatus includes a magnetic head that reads information from the magnetic recording layer.
  • the present invention it is possible to provide a magnetic recording medium that can be easily manufactured and whose recording density can be increased, a method for manufacturing the magnetic recording medium, and a magnetic recording apparatus including the magnetic recording medium.
  • FIG. 1 is a perspective view schematically showing a part of a magnetic recording medium 10.
  • FIG. 2 is a diagram schematically showing a cross section along II-II shown in FIG. 1.
  • 6 is a flowchart for explaining a manufacturing method S10 of the magnetic recording medium 10.
  • FIG. 6 is a cross-sectional view for explaining a manufacturing method S10 of the magnetic recording medium 10.
  • FIG. It is a flowchart explaining manufacturing method S20 of the magnetic recording medium by a top-down system.
  • It is sectional drawing explaining manufacturing method S20 of the magnetic recording medium by a top-down system. It is the graph which showed the relationship between the composition of a FeMnPt alloy, and saturation magnetization.
  • Non-Patent Document 4 reports that the A1 disordered structure changes from a ferromagnetic phase to a paramagnetic phase when x> 0.60.
  • the L1 0 ferromagnetic phase the ferromagnetic phase of the L1 0 ordered structure; hereinafter the same
  • the A1 paramagnetic phase A1
  • the present inventors have succeeded in fabricating a [001] crystal orientation of the good film and L1 0 ordering parameter using a predetermined amount replacing an alloy for a portion of Fe or Pt of FePt alloy predetermined element Furthermore, we obtained a magnetic phase diagram different from the previous report. Specifically, when the crystal transformation of the L1 0 ordered structure ⁇ A1 disordered structure is considered, the type and amount of the element to be substituted are appropriately controlled, and by irradiating arbitrary ions, the L1 0 in the same composition It was found that the transformation from the ferromagnetic phase to the A1 paramagnetic phase is possible.
  • FIG. 1 is a perspective view schematically showing a part of the magnetic recording medium 10.
  • FIG. 2 is a diagram schematically showing a cross section along II-II shown in FIG. In FIG. 1 and FIG. 2, for ease of viewing, some reference numerals are omitted for parts having the same configuration (the same applies to the other figures below).
  • the magnetic recording medium 10 is a bit patterned media type magnetic recording medium. That is, the magnetic recording medium 10 includes a base material layer 1 and a magnetic recording layer 2 formed on the base material layer 1, and the magnetic recording layer 2 includes a ferromagnetic portion 3 made of a ferromagnetic material, and Paramagnetic portions 4 made of a paramagnetic material are arranged in the layer surface direction according to a predetermined rule.
  • the base material layer 1 a substrate that can be used for a known magnetic recording medium can be used without any particular limitation.
  • the base material layer 1 can be composed of, for example, a crystalline glass substrate, a silicon substrate having a surface oxide film (for example, a silicon oxide film), a SiC substrate, a carbon substrate, a ceramic substrate, or the like.
  • the thickness of the base material layer 1 is not specifically limited, It can be made the same as that of a well-known magnetic recording medium.
  • the thickness of the base material layer 1 can be 0.635 mm or more and 1.27 mm or less, for example.
  • the magnetic recording layer 2 includes a ferromagnetic portion 3 and a paramagnetic portion 4 arranged according to a predetermined rule.
  • the “predetermined rule” can be the same as the known BPM.
  • the ferromagnetic portion 3 has a quadrangular shape and one side thereof is 4 nm or more and 15 nm or less.
  • variety) between the ferromagnetic parts 3 adjacent in planar view shall be 1 nm or more and 10 nm or less. According to the present invention, it is easy to accurately produce a fine bit pattern as will be described later.
  • the thickness of the magnetic recording layer 2 is not particularly limited and can be the same as that of a known BPM.
  • the thickness of the magnetic recording layer 2 is preferably 4 nm or more and 10 nm or less.
  • the ferromagnetic part 3 includes an alloy having ferromagnetism with a saturation magnetization of 0.37 [Wb / m 2 ] or more and 1.38 [Wb / m 2 ] or less, and the paramagnetic part 4 is saturated. It is configured to include a paramagnetic alloy having a magnetization of 0 [Wb / m 2 ] or more and 0.88 [Wb / m 2 ] or less. Further, the difference between the saturation magnetization of the ferromagnetic alloy contained in the ferromagnetic part 3 and the saturation magnetization of the paramagnetic alloy contained in the paramagnetic part 4 is 0.10 [Wb / m 2 ] or more. .
  • the saturation magnetization of the alloy included in the ferromagnetic portion 3 is preferably 0.75 [Wb / m 2 ] or more and 1.38 [Wb / m 2 ] or less, and the saturation of the alloy included in the paramagnetic portion 4 is preferable.
  • the magnetization is preferably 0 [Wb / m 2 ] or more and 0.38 [Wb / m 2 ] or less, and the difference between the saturation magnetizations is preferably 0.37 [Wb / m 2 ] or more.
  • the alloy contained in the ferromagnetic part 3 and the alloy contained in the paramagnetic part 4 have substantially the same composition.
  • substantially the same composition is not limited to the case where the compositions are exactly the same, and the ferromagnetic portion 3 is formed when the paramagnetic portion 4 is formed by irradiating ions as described later.
  • the composition of the alloy contained in the ferromagnetic part 3 and the alloy contained in the paramagnetic part 4 is represented by the following formula (1) or (2). (Fe 1-x M 1 x ) Pt (1) (However, in the above formula (1), M 1 is Mn or Nb, and x is a saturation magnetization in the L1 0 ordered structure of 0.37 [Wb / m 2 ] or more and 1.38 [Wb / m 2 ].
  • the saturation magnetization in the A1 irregular structure is 0 [Wb / m 2 ] or more and 0.88 [Wb / m 2 ] or less, and the difference between the saturation magnetizations is 0.10 [Wb / m 2 ] or more.
  • Fe (Pt 1-y M 2 y ) (2) (However, in the above formula (2), M 2 is any one of Ru, Rh, Os, and Ir, and y is a saturation magnetization in the L1 0 ordered structure of 0.37 [Wb / m 2 ] or more 1 .38 [Wb / m 2 ] or less, the saturation magnetization in the A1 disordered structure is 0 [Wb / m 2 ] or more and 0.88 [Wb / m 2 ] or less, and the difference between the saturation magnetizations is 0.10. (It is a value that is equal to or greater than [Wb / m 2 ].)
  • x is 0.3 ⁇ x ⁇ 0.54, preferably 0.5 ⁇ x ⁇ 0.54, and most preferably X is about 0.52.
  • the ferromagnetic structure 3 and the paramagnetic part 4 are obtained by changing the crystal structure without changing the alloy composition in a part of the thin film. It is divided into. Part this time, specifically, after forming a thin film of FePt-based alloy having an L1 0 ordered structure, in which the L1 0 ordered structure in some of the thin film is changed into A1 disordered structure, does not change the crystal structure Becomes the ferromagnetic part 3, and the part changed to the A1 irregular structure becomes the paramagnetic part 4.
  • the magnetic recording medium 10 a magnetic recording medium having a high recording density, it is preferable to increase the magnetic anisotropy of the alloy contained in the ferromagnetic portion 3.
  • the FePt alloy thin film having the L1 0 ordered structure with high [001] orientation and high L1 0 order . That is, the (001) plane of the crystal constituting the FePt alloy included in the ferromagnetic portion 3 is parallel to the surface of the magnetic recording layer 2, and the [001] direction is relative to the surface of the magnetic recording layer 2. It is preferable to face in the vertical direction.
  • the ferromagnetic portion 3 is made of an alloy having high magnetic anisotropy. Therefore, it is easy to increase the recording density of the magnetic recording layer 2.
  • the magnetic recording layer 2 can be produced by forming a thin film having the same composition and then irradiating a part of the thin film with ions to change the crystal structure. Therefore, it is easy to form a fine bit pattern and to easily increase the recording density of the magnetic recording layer 2. Further, when the magnetic recording layer 2 is manufactured, it is not necessary to finally polish or heat the surface. Therefore, the magnetic recording medium 10 can be easily manufactured as compared with the conventional magnetic recording medium manufactured by the top-down method described above, and the product quality and the yield are easily improved, so that the manufacturing cost can be easily reduced. is there.
  • the magnetic recording medium 10 includes other layers provided in a normal magnetic recording medium. It may be provided. Examples of the other layer include an underlayer provided between the base material layer 1 and the magnetic recording layer 2, a protective layer formed on the magnetic recording layer 2, and the outermost surface of the magnetic recording medium 10. And a lubricant layer.
  • the underlayer can be formed of, for example, a NiFe thin film exhibiting soft magnetism.
  • the protective layer can be formed of a thin film such as DLC (diamond-like carbon) or hydrogenated carbon.
  • the lubricant layer can be formed of a thin film such as a fluorocarbon resin.
  • FIG. 3 is a flowchart for explaining the manufacturing method S10 of the magnetic recording medium 10.
  • FIG. 4 is a cross-sectional view illustrating a method for manufacturing the magnetic recording medium 10.
  • the manufacturing method S10 includes a film forming step S1, a mask arranging step S2, an ion irradiation step S3, and a mask removing step S4.
  • a film forming step S1 As shown in FIG. 3, the manufacturing method S10 includes a film forming step S1, a mask arranging step S2, an ion irradiation step S3, and a mask removing step S4.
  • these steps will be described.
  • a substrate used for the base material layer 1 is prepared, and a precursor layer 2 ′ serving as a precursor of the magnetic recording layer 2 is formed on the substrate. It is a process.
  • the precursor layer 2 ′ has an L1 0 ordered structure, the composition is represented by the above formula (1) or (2), and the saturation magnetization is 0.37 [Wb / m 2 ] or more and 1.38 [Wb]. / M 2 ]
  • the following is a thin film containing an alloy having ferromagnetism.
  • the precursor layer 2 ′ is made of a material suitable for the ferromagnetic portion 3.
  • the precursor layer 2 ' preferably includes a high [001] orientation and high L1 0 order parameter and the provided alloy. That is, the (001) plane of the crystal constituting the alloy contained in the precursor layer 2 ′ is parallel to the surface of the precursor layer 2 ′, and the [001] direction is on the surface of the precursor layer 2 ′. On the other hand, it is preferably oriented in the vertical direction.
  • the film forming step S1 is preferably a step of heating a thin film containing a FePt-based alloy and a metal oxide described later on the base material layer 1 and then heating the thin film.
  • the method for forming the precursor layer 2 ′ containing the FePt-based alloy and the metal oxide on the base material layer 1 is not particularly limited.
  • a method of simultaneous sputtering film formation using a metal and a metal oxide constituting an FePt alloy as targets can be considered.
  • Sputtering film formation can also be performed using an FePt alloy as a target instead of the metal constituting the FePt alloy.
  • Sputter deposition may be performed using a material in which a metal oxide is previously mixed with an FePt-based alloy as a target.
  • the content ratio of (Fe 1-x M 1 x ) and Pt in the precursor layer 2 ′ obtained in the film forming step S1 or the content ratio of Fe to (Pt 1-y M 2 y ) is 40 It is preferably about 60:60 to 40.
  • the present inventors have found that by rapidly heating with adding a specific metal oxide in the FePt alloy, a thin film having a high [001] orientation and high L1 0 degree of order is obtained.
  • the FePt alloy film formed by sputtering at room temperature is an aggregate of fcc fine crystals.
  • this FePt alloy film is heated to several hundred degrees Celsius, the film is recrystallized to cause grain growth. Since the fcc phase is a metastable phase and the L1 0 phase is a thermal equilibrium phase, if sufficient atomic diffusion occurs, the fcc phase is transformed into the L1 0 phase in this recrystallization process.
  • the L1 0 phase is [001] oriented in the direction perpendicular to the film plane in order to relax the strain.
  • This tensile stress is gradually relieved with the passage of time.
  • the recrystallization process proceeds while the tensile stress is not relieved by rapid thermal annealing, the tensile stress has high [001] orientation and high L1 0 order.
  • An FePt-based alloy thin film can be formed.
  • metal oxide when metal oxide is formed by sputtering, metal atoms, oxygen atoms, and oxide molecules separated by sputtering fly onto the substrate.
  • metal oxide and an FePt alloy are simultaneously formed by sputtering with the substrate at room temperature, the formed thin film becomes a mixture of metal atoms, oxygen atoms, metal oxide molecules, and FePt alloys.
  • this thin film is heated, the metal atoms move in the FePt alloy of the parent phase and recombine with oxygen atoms to form oxides.
  • the metal atoms are likely to move through the FePt alloy even at low temperatures, so that a recrystallization process is induced at low temperatures.
  • the recombined oxide promotes the formation of a film having a high [001] orientation by controlling the crystal growth process of the thin film during heating.
  • the oxide formation free energy of the metal atom to be added is higher than the oxide formation free energy of Fe, an Fe oxide is formed, and the added metal atom is dissolved or precipitated at the grain boundary in the FePt alloy. Therefore, the characteristics of FePt-based alloy having an L1 0 structure is deteriorated.
  • the metal constituting the metal oxide to be added preferably has an oxide formation free energy ⁇ G f ° at room temperature of ⁇ 850 kJ / mol or more and ⁇ 500 kJ / mol or less.
  • Examples of the metal oxide that satisfies the range of free energy for generating the oxide include SiO 2 , ZnO, and Na 2 O. Of these oxides, SiO 2 and ZnO are preferable from the viewpoint of ease of use and safety.
  • the metal constituting the predetermined metal oxide that can be used in the present invention is preferably a metal having a melting point of 100 ° C. or higher and 500 ° C. or lower. Considering the practical use as a magnetic recording medium, along with the progress of the L1 0 ordered at a low temperature at 100 ° C. or higher 500 ° C. or less, it is because it is desirable to achieve a high [001] orientation.
  • the diffusion coefficient of an alloy is given by the sum of the diffusion coefficients of the elements constituting the alloy, but the element having the largest diffusion coefficient dominates the diffusion process.
  • the diffusion coefficient of the metal element can be roughly estimated by the melting point.
  • the melting point of Fe and Pt is 1500 ° C. or higher, and the diffusion coefficient near room temperature is low. Therefore, in order to cause diffusion at a temperature of about 100 ° C. to 500 ° C., it is necessary to add a substance having a melting point of 100 ° C. to 500 ° C.
  • ZnO is an example of a metal oxide that satisfies the above melting point range.
  • the addition amount of the metal oxide is preferably 2.5% by volume or more and 12.5% by volume or less with respect to the total amount of the FePt alloy and the metal oxide to be added. If the addition amount of the metal oxide is too small or too large, the [001] orientation of the FePt-based alloy obtained after the heat treatment tends to be low and the magnetic anisotropy tends to be inferior.
  • heat treatment is performed.
  • the temperature increase rate in the heat treatment is preferably 30 ° C./second or more, and more preferably 100 ° C./second or more.
  • a fast heating rate will have an FePt-based alloy high [001] orientation, and the high L1 0 order parameter, magnetic anisotropy is improved.
  • heating temperature is 400 degreeC or more and 500 degrees C or less. If this temperature is too low, the [001] orientation of the FePt-based alloy tends to decrease, and if it is too high, it is not preferable from the viewpoint of productivity.
  • the mask placement step S2 will be described.
  • ions are not irradiated except for the portion irradiated with ions, that is, the portion to be the paramagnetic portion 4.
  • the material which comprises the mask 5 will not be specifically limited if the ion irradiated in ion irradiation process S3 does not permeate
  • Specific examples of the material constituting the mask 5 include organic substances such as ZEP520A (manufactured by Zeon Corporation, electron beam resist) and nanoimprint resin.
  • the ion irradiation step S3 is a step of irradiating the precursor layer 2 ′ formed in the film forming step S1 with arbitrary ions.
  • the present inventors irradiate a thin film having an L1 0 ordered structure with about 0.10 to 1.0 at% by irradiating an arbitrary ion accelerated to several keV by the previous research, thereby obtaining an A1 disordered structure. It has been found that it can be transformed into (see Non-Patent Documents 5 and 6). Further, as described above, the present inventors have found that the saturation magnetization changes greatly by changing the crystal structure in a predetermined FePt-based alloy.
  • a portion ions are irradiated becomes A1 disordered structure from L1 0 ordered structure, a paramagnetic part 4.
  • the lower portion of the mask 5 which ions are not irradiated of the precursor layer 2 'maintains the ferromagnetic maintains an L1 0 ordered structure, the ferromagnetic portion 3.
  • the species is not particularly limited.
  • the ion irradiation amount is preferably 0.10 at% or more and 2.0 at% or less of the portion of the precursor layer 2 ′ that is irradiated with ions, that is, the portion that becomes the paramagnetic portion 4.
  • 0.10At% or more an L1 0 ordered structure tends to transformation into A1 disordered structure, by less 2.0 at%, it is possible to prevent the large irregularities are formed on the film surface.
  • the ion species to be irradiated include ions such as Mn, B, Cr, Ga, Nb, Fe, and Pt.
  • ions such as Mn, B, Cr, Ga, Nb, Fe, and Pt.
  • Mn ions it is preferable to use Mn ions as the ion species to be irradiated.
  • the size of the ion recording step S3 can be reduced when used as a magnetic recording medium. It can be ignored.
  • the mask removal step S4 is a step of removing the mask 5 arranged in the mask arrangement step S2.
  • the method for removing the mask 5 can be appropriately selected according to the material constituting the mask 5 and the like. For example, there is a method of performing ultrasonic cleaning in an organic substance (dimethyl sulfoxide) maintained at 90 ° C. or higher.
  • the magnetic recording medium 10 may further include other layers in addition to the base layer 1 and the magnetic recording layer 2 in the same manner as the conventional magnetic recording medium.
  • the manufacturing method S10 further includes a step of forming these other layers.
  • the method for forming these other layers is not particularly limited, and can be performed in the same manner as a conventional method for producing a magnetic recording medium.
  • the film can be formed by a plasma vapor deposition method or the like.
  • the present invention has been described by exemplifying a mode applied to BPM.
  • the present invention is a magnetic recording having a magnetic recording layer having a ferromagnetic portion and a paramagnetic portion arranged according to a predetermined rule. It is applicable to a medium and a manufacturing method thereof. That is, the present invention is applicable to DTM.
  • the magnetic recording medium of the present invention described above is a well-known magnetic head or the like that records information to and / or reads information from a rotating shaft and a motor or magnetic recording layer that rotates the magnetic recording medium.
  • a magnetic recording device can be obtained by combining with components provided in the magnetic recording device.
  • % used here means volume% with respect to the entire magnetic recording layer (thin film) unless otherwise specified.
  • a thermally oxidized Si substrate (a substrate on which the surface of the Si substrate is covered with an oxide film of SiO 2 ) above, (Fe 1-x Mn x ) SiO 2 to Pt alloy was added 10 vol%, and a thin film of (Fe 1-x Mn x) Pt alloys with A1 disordered structure.
  • the film forming conditions were room temperature under Ar gas of 0.5 Pa.
  • a (Fe 1-x Mn x ) Pt alloy thin film having an A1 disordered structure is prepared in the same manner as described above, and the thin film is subjected to heat treatment in a vacuum using a rapid vacuum heat treatment apparatus (RTA). did.
  • the heat treatment conditions were a temperature rising rate of 100 ° C./second, an reached temperature of 700 ° C., and a holding time at the reached temperature of 10 minutes.
  • RTA rapid vacuum heat treatment apparatus
  • a thin film of (Fe 1-x Mn x ) Pt alloy having an A1 disordered structure and a thin film of (Fe 1-x Mn x ) Pt alloy having an L1 0 ordered structure were prepared as described above.
  • a (Fe 0.48 Mn 0.52 ) Pt alloy thin film is prepared as described above, a microfabricated mask is arranged on the thin film, and the thin film is irradiated with Ga ions accelerated to 30 keV by 0.1 at%. The bit pattern was transferred. At this time, the regions covered by the masks holds an L1 0 ferromagnetic phase, a region not covered with the mask was transformed into A1 paramagnetic phase is irradiated ions. Thereafter, the mask was removed to complete the BPM.
  • a magnetic recording medium in which the recording density can be easily increased can be easily manufactured.

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Abstract

A magnetic recording medium equipped with a magnetic recording layer, said magnetic recording layer comprising ferromagnetic parts and paramagnetic parts that are aligned in accordance with a definite rule, wherein: the ferromagnetic parts contain a ferromagnetic alloy having a saturation magnetization of 0.37-1.38 [Wb/m2] inclusive; said paramagnetic parts contain a paramagnetic alloy having a saturation magnetization of 0-0.88 [Wb/m2] inclusive; the alloy contained in the ferromagnetic parts and the alloy contained in the paramagnetic parts have almost the same composition, said composition being represented by formula (1) or formula (2); and the alloy contained in the ferromagnetic parts has an L10 ordered structure, while the alloy contained in the paramagnetic parts has an A1 disordered structure. Thus, a magnetic recording medium that can be easily manufactured and has an increased recording density can be provided. (Fe1-xM1 x)Pt (1) wherein M1 stands for Mn or Nb. Fe(Pt1-yM2 y) (2) wherein M2 stands for Ru, Rh, Os or Ir.

Description

ＦｅＰｔ系合金における強磁性－常磁性相変化を利用した磁気記録媒体Magnetic recording media using ferromagnetic-paramagnetic phase change in FePt alloys
　本発明は、強磁性体と非磁性体とが所定の規則によって配列された磁気記録層を有する磁気記録媒体、該磁気記録媒体の製造方法、及び該磁気記録媒体を備えた磁気記録装置に関する。 The present invention relates to a magnetic recording medium having a magnetic recording layer in which a ferromagnetic material and a non-magnetic material are arranged according to a predetermined rule, a method for manufacturing the magnetic recording medium, and a magnetic recording device including the magnetic recording medium.
　磁気記録装置であるハードディスクドライブは、データを記録可能な磁気記録媒体として円盤状のハードディスクを備えている。また、ハードディスクドライブはハードディスクを高速回転させる回転軸やモーターなどの駆動装置も備えている。この駆動装置によってハードディスクを高速回転させ、そのハードディスク上で磁気ヘッドを移動させることにより、ハードディスクに備えられた磁気記録層に情報を記録したり、磁気記録層から情報を読み出したりすることができる。 A hard disk drive, which is a magnetic recording device, includes a disk-shaped hard disk as a magnetic recording medium capable of recording data. The hard disk drive also includes a drive device such as a rotating shaft and a motor for rotating the hard disk at high speed. By rotating the hard disk at high speed with this drive device and moving the magnetic head on the hard disk, information can be recorded on or read from the magnetic recording layer provided in the hard disk.
　上記のような磁気記録媒体の記憶容量を増大させるには、磁気記録層の面記録密度を高くすることが考えられる。また、磁気記録層の面記録密度を向上させるには、磁気記録層に備えられた記録ビットを微細化することが考えられる。しかしながら、記録ビットの微細化を進めると、熱エネルギーにより記録ビットを構成する強磁性体の磁化方向が変化し、記録ビットに記録されていた情報が失われてしまう、いわゆる「熱揺らぎ」が問題となる。このような熱揺らぎの影響を抑えるには、熱揺らぎに強い特性を有する材料、すなわち垂直磁気異方性が高い強磁性体材料で記録ビットを構成することが考えられる。 In order to increase the storage capacity of the magnetic recording medium as described above, it is conceivable to increase the surface recording density of the magnetic recording layer. In order to improve the surface recording density of the magnetic recording layer, it is conceivable to make the recording bits provided in the magnetic recording layer fine. However, if the recording bit is further miniaturized, the so-called “thermal fluctuation”, in which the information recorded in the recording bit is lost due to the change in magnetization direction of the ferromagnetic material constituting the recording bit due to thermal energy, is a problem. It becomes. In order to suppress the influence of such thermal fluctuation, it is conceivable that the recording bit is composed of a material having a strong characteristic against thermal fluctuation, that is, a ferromagnetic material having high perpendicular magnetic anisotropy.
　面記録密度が数テラビット／平方インチの超高密度磁気記録媒体を実現可能な材料としては、Ｌ１０規則構造を有するＦｅＰｔ合金が期待されている。Ｌ１０規則構造を有するＦｅＰｔ合金は熱揺らぎに強い特性を有することから、これを用いて記録ビットを構成した超高密度磁気記録媒体の実現が期待されている。なお、「Ｌ１０規則構造」とは、ｆｃｔ構造で二種の原子が交互に積層し、且つ該二種の原子の組成比が１：１である構造である。 As the material capable of realizing a super high density magnetic recording medium of the surface recording density of several terabits / square inch, FePt alloy having an L1 0 ordered structure is expected. Since the FePt alloy having the L1 0 ordered structure has strong characteristics against thermal fluctuation, it is expected to realize an ultra-high density magnetic recording medium in which a recording bit is formed using this. The “L1 0 ordered structure” is a structure in which two types of atoms are alternately stacked in an fct structure and the composition ratio of the two types of atoms is 1: 1.
　Ｌ１０規則構造を有するＦｅＰｔ合金による薄膜の作製方法としては、例えば、下記非特許文献１に記載されたものがある。非特許文献１に記載された技術によれば、ＦｅＰｔ合金の薄膜にＳｉＯ２を所定量添加して急速加熱することにより、高［００１］配向性と高Ｌ１０規則度とを有するＦｅＰｔ合金薄膜を得られる。 As a method for manufacturing a thin film by FePt alloy having an L1 0 ordered structure, for example, it is disclosed in the following Non-Patent Document 1. According to the technique described in Non-Patent Document 1, a FePt alloy thin film having high [001] orientation and high L1 0 order by adding a predetermined amount of SiO 2 to a FePt alloy thin film and rapidly heating it. Can be obtained.
　また、ＦｅＰｔ合金のＦｅ又はＰｔの一部を他の元素に置換したＦｅＰｔ系合金（ＦｅＰｔ合金、及び、ＦｅＰｔ合金のＦｅ又はＰｔの一部を他の元素に置換した合金を「ＦｅＰｔ系合金」という。以下同じ。）についての研究も進められている。下記非特許文献２、３には、ＦｅＰｔ合金のＦｅ原子サイトをＭｎで置換したＦｅＭｎＰｔ合金のバルクに関する技術が記載されており、下記非特許文献４にはＦｅＭｎＰｔ合金の多結晶薄膜に関する技術が記載されている。 Further, an FePt alloy in which Fe or a part of Pt in the FePt alloy is replaced with another element (an FePt alloy and an alloy in which a part of Fe or Pt in the FePt alloy is replaced with another element is referred to as an “FePt alloy”. (The same shall apply hereinafter)). Non-Patent Documents 2 and 3 below describe the technology related to the bulk of the FeMnPt alloy in which the Fe atom site of the FePt alloy is replaced with Mn, and the following Non-Patent Document 4 describes the technology related to the polycrystalline thin film of the FeMnPt alloy. Has been.
　一方、超高密度磁気記録媒体を実現するための記録方式としては、ビットパターンドメディア（以下、「ＢＰＭ」と略記する場合がある。）が注目されている。ＢＰＭとは、ナノスケールの強磁性体（ドット）が非磁性体中に所定の規則に従って２次元的に配置された構造を有する磁気記録媒体である。 On the other hand, bit patterned media (hereinafter sometimes abbreviated as “BPM”) has attracted attention as a recording method for realizing an ultra-high density magnetic recording medium. BPM is a magnetic recording medium having a structure in which nanoscale ferromagnetic materials (dots) are two-dimensionally arranged in a nonmagnetic material according to a predetermined rule.
　このようなＢＰＭの作製方法としては、いわゆるトップダウン方式が一般的である。すなわち、まず基板上に強磁性体の薄膜を形成し、該薄膜上にマスクを配置して非磁性体を配置させる予定の部分のみ該薄膜をミリングし、マスクを除去してからミリングした箇所に非磁性体を成膜して埋め戻し、その後表面を研磨する方法である。この方法では、ミリングや表面研磨によって強磁性体が受けたダメージを回復する必要があるため、最終的に熱処理を行う必要がある。 A so-called top-down method is generally used as a method for producing such BPM. That is, a ferromagnetic thin film is first formed on a substrate, a mask is placed on the thin film, and the thin film is milled only at a portion where a nonmagnetic material is to be placed. In this method, a nonmagnetic material is deposited and backfilled, and then the surface is polished. In this method, since it is necessary to recover the damage received by the ferromagnetic material by milling or surface polishing, it is necessary to finally perform heat treatment.
　また、ＢＰＭの他の作製方法としては、下記特許文献１に記載されているように、強磁性体又は反強磁性体のいずれか一方によって基板上に薄膜を形成した後、イオン打ち込みや添加元素の拡散によって組成調整することにより、形成された薄膜の所定の領域を強磁性体又は反強磁性体の他方に改質する方法も考えられる。なお、磁性体を改質させる方法としては、下記非特許文献５、６に記載されているように、イオンを照射することによって結晶構造を変化させる方法もある。イオン照射によるＢＰＭ作製の試みについては下記非特許文献７～１０に記載されている（非特許文献７はＣｏ／Ｐｄ多層膜、非特許文献８はＣｒＰｔ３規則合金薄膜、非特許文献９はＭｎＢｉＣｕ薄膜、非特許文献１０はＭｎＡｌ薄膜について記載されている。）。 As another manufacturing method of BPM, as described in Patent Document 1 below, after forming a thin film on a substrate with either a ferromagnetic material or an antiferromagnetic material, ion implantation or additive elements are performed. A method is also conceivable in which a predetermined region of the formed thin film is modified to the other of a ferromagnetic material or an antiferromagnetic material by adjusting the composition by diffusing. As a method of modifying the magnetic material, there is a method of changing the crystal structure by irradiating ions as described in Non-Patent Documents 5 and 6 below. Attempts to produce BPM by ion irradiation are described in the following non-patent documents 7 to 10 (non-patent document 7 is a Co / Pd multilayer film, non-patent document 8 is a CrPt 3 ordered alloy thin film, and non-patent document 9 is MnBiCu. Thin Film, Non-Patent Document 10 describes a MnAl thin film.)
特開２００９－１５１８９９号公報JP 2009-151899 A
　上述したように、ＢＰＭのような強磁性体と非磁性体とが所定の規則によって２次元的に配列された磁気記録媒体を作製するには、トップダウン方式が一般的であった。トップダウン方式は、図５に示したようにＳ２１～Ｓ２７の工程を有する。図５はトップダウン方式による磁気記録媒体の製造方法Ｓ２０を説明するフロー図である。図６は製造方法Ｓ２０を説明する断面図である。 As described above, the top-down method is generally used to produce a magnetic recording medium in which a ferromagnetic material such as BPM and a non-magnetic material are two-dimensionally arranged according to a predetermined rule. The top-down method has steps S21 to S27 as shown in FIG. FIG. 5 is a flowchart for explaining a manufacturing method S20 of the magnetic recording medium by the top-down method. FIG. 6 is a cross-sectional view illustrating the manufacturing method S20.
　成膜工程Ｓ２１は、図６（Ａ）に示したように基板２１上に強磁性体の薄膜２２’を形成する工程である。成膜工程Ｓ２１は、例えばＬ１０規則構造を有するＦｅＰｔ合金の薄膜２２’を形成する工程である。マスク配置工程Ｓ２２は、図６（Ｂ）に示したように、成膜工程Ｓ２１で形成した薄膜２２’のうち、非強磁性体を配置する予定の箇所のみミリングできるように該薄膜２２’上にマスク２５を配置する工程である。ミリング工程Ｓ２３は、図６（Ｃ）に示したように、成膜工程Ｓ２１で形成した薄膜２２’のうち、非強磁性体を配置する予定箇所２６のみミリングする工程である。ミリング工程Ｓ２３は、例えばイオンミリング（イオン照射量１００ａｔ％）により薄膜２２’をビットパターン状に微細加工する工程である。マスク除去工程Ｓ２４は、図６（Ｄ）に示したように、マスク配置工程Ｓ２２で配置したマスク２５を除去する工程である。埋め戻し成膜工程Ｓ２５は、図６（Ｅ）に示したように、非強磁性体２７を成膜して、ミリング工程Ｓ２３でミリングした箇所２６を非強磁性体２７で埋め戻す工程である。表面研磨工程Ｓ２６は、図６（Ｆ）に示したように、工程Ｓ２１～Ｓ２５を経て得られた、強磁性体及び非強磁性体を有する薄膜の表面を研磨し、該薄膜の表面を平坦化する工程である。熱処理工程Ｓ２７は、工程Ｓ２１～Ｓ２６を経て得られた薄膜に熱処理を施す工程である。Ｌ１０規則構造はイオンミリングや表面研磨処理に対して弱いため、熱処理を施してＬ１０規則構造が受けたダメージを回復する必要がある。 The film forming step S21 is a step of forming a ferromagnetic thin film 22 ′ on the substrate 21 as shown in FIG. Film forming step S21 is, for example, a step of forming a thin film 22 'of the FePt alloy having an L1 0 ordered structure. As shown in FIG. 6B, the mask arrangement step S22 is performed on the thin film 22 ′ so that only the portion where the non-ferromagnetic material is to be arranged can be milled out of the thin film 22 ′ formed in the film formation step S21. In this step, the mask 25 is disposed on the substrate. As shown in FIG. 6C, the milling step S23 is a step of milling only the planned portion 26 where the non-ferromagnetic material is arranged in the thin film 22 ′ formed in the film forming step S21. The milling step S23 is a step of finely processing the thin film 22 ′ into a bit pattern by, for example, ion milling (ion irradiation amount 100 at%). The mask removal step S24 is a step of removing the mask 25 arranged in the mask arrangement step S22 as shown in FIG. As shown in FIG. 6E, the backfill film forming step S25 is a step in which the non-ferromagnetic material 27 is formed and the portion 26 milled in the milling step S23 is backfilled with the nonferromagnetic material 27. . In the surface polishing step S26, as shown in FIG. 6 (F), the surface of the thin film having ferromagnetic and non-ferromagnetic materials obtained through steps S21 to S25 is polished, and the surface of the thin film is flattened. It is a process to convert. The heat treatment step S27 is a step of performing a heat treatment on the thin film obtained through the steps S21 to S26. Since the L1 0 ordered structure is weak against ion milling and surface polishing, it is necessary to recover the damage received by the L1 0 ordered structure by heat treatment.
　上記のようにトップダウン方式では熱処理工程Ｓ２７を行う必要がある。しかしながら、熱処理は必ず原子相互拡散を伴うため、埋め戻し成膜工程Ｓ２５において成膜された非強磁性体２７と薄膜２２’を構成するＦｅＰｔ合金とが混合し、最終的には強磁性部の磁気特性を劣化させる虞があった。
  また、上記のようなトップダウン方式では、工程数が多くなるため磁気記録媒体の製造コストが高くなりやすく、表面を研磨する工程を含むため製品品質や歩留まりが低下しやすかった。 As described above, in the top-down method, it is necessary to perform the heat treatment step S27. However, since the heat treatment always involves atomic interdiffusion, the non-ferromagnetic material 27 formed in the backfill film forming step S25 and the FePt alloy constituting the thin film 22 ′ are mixed, and finally the ferromagnetic part There was a risk of deteriorating magnetic properties.
In the top-down method as described above, the number of steps increases, so the manufacturing cost of the magnetic recording medium tends to increase, and the process of polishing the surface tends to reduce the product quality and yield.
　一方、上述したようにトップダウン方式によらずにイオンを照射する等してＢＰＭを作製する方法も考えられてはいたが、このような方法に従来適用されていた磁性材料は、超高密度磁気記録媒体に適用するには磁気異方性が不十分であった。すなわち、トップダウン方式によらない従来のＢＰＭの作製方法では、磁気記録媒体の記録密度を十分に高めることが困難であった。 On the other hand, as described above, a method of producing BPM by irradiating ions without using the top-down method has been considered. However, a magnetic material conventionally applied to such a method is an ultra-high density. The magnetic anisotropy was insufficient for application to a magnetic recording medium. That is, it is difficult to sufficiently increase the recording density of the magnetic recording medium with the conventional BPM manufacturing method that does not depend on the top-down method.
　そこで本発明は、容易に製造でき、且つ記録密度を高めることができる磁気記録媒体、該磁気記録媒体の製造方法、及び該磁気記録媒体を備えた磁気記録装置を提供することを課題とする。 Therefore, it is an object of the present invention to provide a magnetic recording medium that can be easily manufactured and can increase the recording density, a method for manufacturing the magnetic recording medium, and a magnetic recording apparatus including the magnetic recording medium.
　本発明者らは、ＦｅＰｔ合金のＦｅ又はＰｔの一部を所定の元素に所定量置換した合金が、これまでに知られていなかった磁気相変化をすることを知見した。すなわち、ＦｅＰｔ合金のＦｅ又はＰｔの一部を所定の元素に所定量置換した合金は、Ｌ１０規則構造を有したハード強磁性材料とすることが可能であるとともに、任意のイオンを照射することによってＡ１不規則構造を有した常磁性材料とすることが可能であることを知見した。本発明は当該知見に基づいてなされたものである。 The present inventors have found that an alloy obtained by substituting a predetermined amount of Fe or Pt of a FePt alloy with a predetermined element undergoes a magnetic phase change that has not been known so far. That is, the alloy obtained by replacing a predetermined amount of a part of Fe or Pt to a predetermined element of the FePt alloy, with may be a hard ferromagnetic material having an L1 0 ordered structure, is irradiated with any ion Thus, it has been found that a paramagnetic material having an A1 irregular structure can be obtained. The present invention has been made based on this finding.
　本発明の第１の態様は、基材層、及び該基材層上に形成された磁気記録層を有し、磁気記録層は所定の規則に従って配列された強磁性部及び常磁性部を備えており、強磁性部は、飽和磁化が０．３７［Ｗｂ／ｍ２］以上１．３８［Ｗｂ／ｍ２］以下の強磁性を有する合金を含んでおり、常磁性部は、飽和磁化が０［Ｗｂ／ｍ２］以上０．８８［Ｗｂ／ｍ２］以下の常磁性を有する合金を含んでおり、強磁性部に含まれる合金の飽和磁化と、常磁性部に含まれる合金の飽和磁化との差が０．１０［Ｗｂ/ｍ２］以上であり、強磁性部に含まれる合金、及び常磁性部に含まれる合金は、組成が略同一であり、且つ当該組成は下記（１）式又は（２）式で表わされ、強磁性部に含まれる合金はＬ１０規則構造を有し、常磁性部に含まれる合金はＡ１不規則構造を有する、磁気記録媒体である。
    （Ｆｅ１－ｘＭ１ ｘ）Ｐｔ　　（１）
（ただし、上記（１）式において、Ｍ１はＭｎ又はＮｂであり、ｘは、Ｌ１０規則構造での飽和磁化が０．３７［Ｗｂ／ｍ２］以上１．３８［Ｗｂ／ｍ２］以下となり、Ａ１不規則構造での飽和磁化が０［Ｗｂ／ｍ２］以上０．８８［Ｗｂ／ｍ２］以下となり、両者の飽和磁化の差が０．１０［Ｗｂ/ｍ２］以上となる値である。）
    Ｆｅ（Ｐｔ１－ｙＭ２ ｙ）　　（２）
（ただし、上記（２）式において、Ｍ２はＲｕ、Ｒｈ、Ｏｓ、又はＩｒのいずれかであり、ｙは、Ｌ１０規則構造での飽和磁化が０．３７［Ｗｂ／ｍ２］以上１．３８［Ｗｂ／ｍ２］以下となり、Ａ１不規則構造での飽和磁化が０［Ｗｂ／ｍ２］以上０．８８［Ｗｂ／ｍ２］以下となり、両者の飽和磁化の差が０．１０［Ｗｂ/ｍ２］以上となる値である。） A first aspect of the present invention includes a base material layer and a magnetic recording layer formed on the base material layer, and the magnetic recording layer includes a ferromagnetic portion and a paramagnetic portion arranged according to a predetermined rule. The ferromagnetic part includes an alloy having ferromagnetism with a saturation magnetization of 0.37 [Wb / m 2 ] or more and 1.38 [Wb / m 2 ] or less, and the paramagnetic part has a saturation magnetization of An alloy having a paramagnetism of 0 [Wb / m 2 ] or more and 0.88 [Wb / m 2 ] or less is included, and the saturation magnetization of the alloy included in the ferromagnetic portion and the saturation of the alloy included in the paramagnetic portion The difference from the magnetization is 0.10 [Wb / m 2 ] or more, and the alloy contained in the ferromagnetic part and the alloy contained in the paramagnetic part have substantially the same composition, and the composition is as follows (1 ) is represented by formula or (2), the alloy contained in the ferromagnetic portion has an L1 0 ordered structure, alloy included in the paramagnetic portion Having the A1 disordered structure, a magnetic recording medium.
(Fe 1-x M 1 x ) Pt (1)
(However, in the above formula (1), M 1 is Mn or Nb, and x is a saturation magnetization in the L1 0 ordered structure of 0.37 [Wb / m 2 ] or more and 1.38 [Wb / m 2 ]. The saturation magnetization in the A1 irregular structure is 0 [Wb / m 2 ] or more and 0.88 [Wb / m 2 ] or less, and the difference between the saturation magnetizations is 0.10 [Wb / m 2 ] or more. Value.)
Fe (Pt 1-y M 2 y ) (2)
(However, in the above formula (2), M 2 is any one of Ru, Rh, Os, and Ir, and y is a saturation magnetization in the L1 0 ordered structure of 0.37 [Wb / m 2 ] or more 1 .38 [Wb / m 2 ] or less, the saturation magnetization in the A1 disordered structure is 0 [Wb / m 2 ] or more and 0.88 [Wb / m 2 ] or less, and the difference between the saturation magnetizations is 0.10. (Wb / m 2 ] or more.)
　本発明において「基材層上に形成された磁気記録層を有し」とは、基材層上に直接磁気記録層が積層されている形態に限定されず、他の層を介して基材層および磁気記録層が積層されている形態も含む概念である。また、「所定の規則に従って配列された強磁性部及び常磁性部」の「所定の規則」とは、従来のＢＰＭやディスクリートトラックメディア（以下、「ＤＴＭ」ということがある。）における強磁性体及び非磁性体の配列規則と同様の規則を意味する。さらに、「強磁性部に含まれる合金、及び常磁性部に含まれる合金は、組成が略同一」とは、強磁性部に含まれる合金の組成と常磁性部に含まれる合金の組成とが厳密に同一であることに限定されず、磁気記録層の作製過程において後述するようにしてイオンを照射した際に、該イオンが残留して強磁性部に含まれる合金の組成と常磁性部に含まれる合金の組成とが僅かに異なる形態も含む概念であり、具体的には９７ａｔ％以上同一であることを意味する。 In the present invention, “having a magnetic recording layer formed on a base material layer” is not limited to the form in which the magnetic recording layer is directly laminated on the base material layer, and the base material is interposed via another layer. It is a concept including a form in which a layer and a magnetic recording layer are laminated. The “predetermined rule” of the “ferromagnetic part and paramagnetic part arranged according to a predetermined rule” is a ferromagnetic material in a conventional BPM or discrete track media (hereinafter, also referred to as “DTM”). And the same rule as the arrangement rule of the non-magnetic material. Furthermore, “the alloy contained in the ferromagnetic part and the alloy contained in the paramagnetic part have substantially the same composition” means that the composition of the alloy contained in the ferromagnetic part and the composition of the alloy contained in the paramagnetic part are It is not limited to exactly the same, and when ions are irradiated as described later in the process of manufacturing the magnetic recording layer, the ions remain and the composition of the alloy contained in the ferromagnetic part and the paramagnetic part It is a concept that includes a form slightly different from the composition of the contained alloy, and specifically means that it is the same at 97 at% or more.
　上記本発明の第１の態様に係る磁気記録媒体は、強磁性部に含まれる合金、及び常磁性部に含まれる合金の組成が（Ｆｅ１－ｘＭｎｘ）Ｐｔである場合、０．３＜ｘ＜０．５４となる。 In the magnetic recording medium according to the first aspect of the present invention, the composition of the alloy contained in the ferromagnetic portion and the alloy contained in the paramagnetic portion is (Fe 1-x Mn x ) Pt. <X <0.54.
　また、上記本発明の第１の態様に係る磁気記録媒体は、磁気記録層が金属酸化物を含むことが好ましい。 In the magnetic recording medium according to the first aspect of the present invention, the magnetic recording layer preferably contains a metal oxide.
　また、上記本発明の第１の態様に係る磁気記録媒体は、磁気記録層に含まれる合金を構成する結晶の（００１）面が、磁気記録層の表面に対して平行であり、［００１］方向が、磁気記録層の表面に対して垂直方向に向いていることが好ましい。 In the magnetic recording medium according to the first aspect of the present invention, the (001) plane of the crystal constituting the alloy contained in the magnetic recording layer is parallel to the surface of the magnetic recording layer, and [001] The direction is preferably perpendicular to the surface of the magnetic recording layer.
　本発明の第２の態様は、基材層、及び該基材層上に形成された磁気記録層を有し、該磁気記録層が、所定の規則に従って配列された強磁性部及び常磁性部を備えた磁気記録媒体の製造方法であって、基材層上に、Ｌ１０規則構造を有するとともに組成が下記（１）式又は（２）式で表わされ、且つ飽和磁化が０．３７［Ｗｂ／ｍ２］以上１．３８［Ｗｂ／ｍ２］以下の強磁性を有する合金を含む薄膜を形成する、薄膜形成工程と、該薄膜の一部に任意のイオンを照射することによって、Ｌ１０規則構造をＡ１不規則構造へと変態させるとともに飽和磁化を０［Ｗｂ／ｍ２］以上０．８８［Ｗｂ／ｍ２］以下にするイオン照射工程と、を有し、薄膜形成工程で形成された薄膜のうち、イオン照射工程でイオンを照射された部分が常磁性部となり、イオンを照射されない部分が強磁性部となる、磁気記録媒体の製造方法である。
　　（Ｆｅ１－ｘＭ１ ｘ）Ｐｔ　　（１）
（ただし、上記（１）式において、Ｍ１はＭｎ又はＮｂであり、ｘは、Ｌ１０規則構造での飽和磁化が０．３７［Ｗｂ／ｍ２］以上１．３８［Ｗｂ／ｍ２］以下となり、Ａ１不規則構造での飽和磁化が０［Ｗｂ／ｍ２］以上０．８８［Ｗｂ／ｍ２］以下となり、両者の飽和磁化の差が０．１０［Ｗｂ/ｍ２］以上となる値である。）
    Ｆｅ（Ｐｔ１－ｙＭ２ ｙ）　　（２）
（ただし、上記（２）式において、Ｍ２はＲｕ、Ｒｈ、Ｏｓ、又はＩｒのいずれかであり、ｙは、Ｌ１０規則構造での飽和磁化が０．３７［Ｗｂ／ｍ２］以上１．３８［Ｗｂ／ｍ２］以下となり、Ａ１不規則構造での飽和磁化が０［Ｗｂ／ｍ２］以上０．８８［Ｗｂ／ｍ２］以下となり、両者の飽和磁化の差が０．１０［Ｗｂ/ｍ２］以上となる値である。） A second aspect of the present invention is a ferromagnetic part and a paramagnetic part having a base material layer and a magnetic recording layer formed on the base material layer, wherein the magnetic recording layer is arranged according to a predetermined rule. a method for manufacturing a magnetic recording medium having a, a base layer, a composition which has an L1 0 ordered structure is represented by the following formula (1) or (2), and the saturation magnetization is 0.37 By forming a thin film including an alloy having a ferromagnetism of [Wb / m 2 ] or more and 1.38 [Wb / m 2 ] or less, and irradiating a part of the thin film with arbitrary ions, An ion irradiation step of transforming the L1 0 ordered structure into an A1 disordered structure and setting the saturation magnetization to 0 [Wb / m 2 ] or more and 0.88 [Wb / m 2 ] or less, Of the formed thin film, the part irradiated with ions in the ion irradiation process is the paramagnetic part. Thus, the method of manufacturing a magnetic recording medium is such that a portion not irradiated with ions becomes a ferromagnetic portion.
(Fe 1-x M 1 x ) Pt (1)
(However, in the above formula (1), M 1 is Mn or Nb, and x is a saturation magnetization in the L1 0 ordered structure of 0.37 [Wb / m 2 ] or more and 1.38 [Wb / m 2 ]. The saturation magnetization in the A1 irregular structure is 0 [Wb / m 2 ] or more and 0.88 [Wb / m 2 ] or less, and the difference between the saturation magnetizations is 0.10 [Wb / m 2 ] or more. Value.)
Fe (Pt 1-y M 2 y ) (2)
(However, in the above formula (2), M 2 is any one of Ru, Rh, Os, and Ir, and y is a saturation magnetization in the L1 0 ordered structure of 0.37 [Wb / m 2 ] or more 1 .38 [Wb / m 2 ] or less, the saturation magnetization in the A1 disordered structure is 0 [Wb / m 2 ] or more and 0.88 [Wb / m 2 ] or less, and the difference between the saturation magnetizations is 0.10. (It is a value that is equal to or greater than [Wb / m 2 ].)
　上記本発明の第２の態様に係る磁気記録媒体の製造方法は、薄膜形成工程で形成する薄膜に含まれる合金の組成が（Ｆｅ１－ｘＭｎｘ）Ｐｔである場合、０．３＜ｘ＜０．５４となる。 In the method for manufacturing a magnetic recording medium according to the second aspect of the present invention, when the composition of the alloy contained in the thin film formed in the thin film forming step is (Fe 1-x Mn x ) Pt, 0.3 <x <0.54.
　また、上記本発明の第２の態様に係る磁気記録媒体の製造方法は、イオン照射工程において用いるイオンがＭｎイオンであり、該Ｍｎイオンの照射量が常磁性部となる部分の０．１０ａｔ％以上２．０ａｔ％以下であることが好ましい。 In addition, in the method for manufacturing a magnetic recording medium according to the second aspect of the present invention, ions used in the ion irradiation step are Mn ions, and the irradiation amount of the Mn ions is 0.10 at% of the portion where the paramagnetic part is formed. It is preferably 2.0 at% or less.
　また、上記本発明の第２の態様に係る磁気記録媒体の製造方法において、薄膜形成工程は、上記（１）式又は（２）式で表わされる組成の合金と、金属酸化物と、を含む薄膜を形成した後、該薄膜を加熱する工程を含むことが好ましい。 In the method for manufacturing a magnetic recording medium according to the second aspect of the present invention, the thin film forming step includes an alloy having a composition represented by the above formula (1) or (2) and a metal oxide. It is preferable to include a step of heating the thin film after forming the thin film.
　本発明の第３の態様は、上記本発明の第１の態様に係る磁気記録媒体と、該磁気記録媒体を回転させる回転軸及びモーターと、磁気記録層に対して情報を記録する、及び／又は磁気記録層から情報を読み出す、磁気ヘッドと、を備える、磁気記録装置である。 According to a third aspect of the present invention, there is provided a magnetic recording medium according to the first aspect of the present invention, a rotating shaft and a motor that rotates the magnetic recording medium, information is recorded on the magnetic recording layer, and / or Alternatively, the magnetic recording apparatus includes a magnetic head that reads information from the magnetic recording layer.
　本発明によれば、容易に製造でき、且つ記録密度を高めることができる磁気記録媒体、該磁気記録媒体の製造方法、及び該磁気記録媒体を備えた磁気記録装置を提供することができる。 According to the present invention, it is possible to provide a magnetic recording medium that can be easily manufactured and whose recording density can be increased, a method for manufacturing the magnetic recording medium, and a magnetic recording apparatus including the magnetic recording medium.
磁気記録媒体１０の一部を概略的に示した斜視図である。1 is a perspective view schematically showing a part of a magnetic recording medium 10. FIG. 図１に示したＩＩ－ＩＩに沿った断面を概略的に示した図である。FIG. 2 is a diagram schematically showing a cross section along II-II shown in FIG. 1. 磁気記録媒体１０の製造方法Ｓ１０を説明するフロー図である。6 is a flowchart for explaining a manufacturing method S10 of the magnetic recording medium 10. FIG. 磁気記録媒体１０の製造方法Ｓ１０を説明する断面図である。6 is a cross-sectional view for explaining a manufacturing method S10 of the magnetic recording medium 10. FIG. トップダウン方式による磁気記録媒体の製造方法Ｓ２０を説明するフロー図である。It is a flowchart explaining manufacturing method S20 of the magnetic recording medium by a top-down system. トップダウン方式による磁気記録媒体の製造方法Ｓ２０を説明する断面図である。It is sectional drawing explaining manufacturing method S20 of the magnetic recording medium by a top-down system. ＦｅＭｎＰｔ合金の組成と飽和磁化との関係を示したグラフである。It is the graph which showed the relationship between the composition of a FeMnPt alloy, and saturation magnetization.
　上述したように、本発明者らは、ＦｅＰｔ合金のＦｅ又はＰｔの一部を所定の元素に所定量置換した合金が、これまでに知られていない磁気相変化をすることを知見した。より具体的には、以下の通りである。これまでに、ＦｅＰｔ系合金の磁気相変化について様々な研究がなされていた。例えば、（Ｆｅ１－ｘＭｎｘ）Ｐｔ合金のバルクは、室温において、Ｌ１０規則構造ではｘ＝０．２５付近で強磁性相から反強磁性相へと変化することが上記非特許文献２で報告されており、Ａ１不規則構造ではｘ＝０．４８付近で強磁性相から常磁性相へと変化することが上記非特許文献３で報告されている。また、（Ｆｅ１－ｘＭｎｘ）Ｐｔ合金の膜厚１００ｎｍ程度の多結晶薄膜の場合には、Ｌ１０規則構造ではｘ＞０．６０で強磁性相から反強磁性相へと変化し、Ａ１不規則構造ではｘ＞０．６０で強磁性相から常磁性相へと変化することが上記非特許文献４で報告されている。ここで、ＦｅＰｔ系合金におけるＬ１０規則構造⇔Ａ１不規則構造の結晶変態を考えると、Ｌ１０強磁性相（Ｌ１０規則構造の強磁性相。以下、同じ。）とＡ１常磁性相（Ａ１不規則構造の常磁性相。以下、同じ。）が同一の組成で形成されることは、従来技術であるバルクおよび薄膜のどちらの形態であっても不可能であったことがわかる。 As described above, the present inventors have found that an alloy obtained by substituting a predetermined amount of Fe or Pt in a FePt alloy with a predetermined element undergoes a magnetic phase change that has not been known so far. More specifically, it is as follows. So far, various studies have been made on the magnetic phase change of FePt-based alloys. For example, the bulk of (Fe 1-x Mn x ) Pt alloy changes from a ferromagnetic phase to an antiferromagnetic phase at room temperature at around x = 0.25 in the L1 0 ordered structure. Non-Patent Document 3 reports that the A1 disordered structure changes from a ferromagnetic phase to a paramagnetic phase around x = 0.48. Further, in the case of a polycrystalline thin film having a film thickness of about 100 nm of a (Fe 1-x Mn x ) Pt alloy, the L1 0 ordered structure changes from a ferromagnetic phase to an antiferromagnetic phase when x> 0.60, Non-Patent Document 4 reports that the A1 disordered structure changes from a ferromagnetic phase to a paramagnetic phase when x> 0.60. Here, when considering the crystal transformation of the L1 0 ordered structure １A1 disordered structure in the FePt-based alloy, the L1 0 ferromagnetic phase (the ferromagnetic phase of the L1 0 ordered structure; hereinafter the same) and the A1 paramagnetic phase (A1). It can be seen that it was impossible to form a paramagnetic phase having a disordered structure (hereinafter the same)) with the same composition in both the bulk and thin film forms of the prior art.
　本発明者らは、ＦｅＰｔ合金のＦｅ又はＰｔの一部を所定の元素に所定量置換した合金を用いてＬ１０規則度と［００１］結晶配向性の良好な薄膜を作製することに成功し、さらに従来の報告とは異なる磁気相図を得た。具体的には、Ｌ１０規則構造⇔Ａ１不規則構造の結晶変態を考えた場合に、置換する元素の種類及び量を適切に制御し、任意のイオンを照射することによって、同一組成においてＬ１０強磁性相からＡ１常磁性相へと変態可能であることを知見した。 The present inventors have succeeded in fabricating a [001] crystal orientation of the good film and L1 0 ordering parameter using a predetermined amount replacing an alloy for a portion of Fe or Pt of FePt alloy predetermined element Furthermore, we obtained a magnetic phase diagram different from the previous report. Specifically, when the crystal transformation of the L1 0 ordered structure ⇔A1 disordered structure is considered, the type and amount of the element to be substituted are appropriately controlled, and by irradiating arbitrary ions, the L1 0 in the same composition It was found that the transformation from the ferromagnetic phase to the A1 paramagnetic phase is possible.
　本発明は上記知見に基づいてなされたものである。以下、本発明の実施形態について説明する。なお、本実施形態は、本発明を実施するための一形態に過ぎず、本発明は本実施形態によって限定されるものではない。 The present invention has been made based on the above findings. Hereinafter, embodiments of the present invention will be described. In addition, this embodiment is only one form for implementing this invention, and this invention is not limited by this embodiment.
　図１は、磁気記録媒体１０の一部を概略的に示した斜視図である。また、図２は、図１に示したＩＩ－ＩＩに沿った断面を概略的に示した図である。なお、図１及び図２では、見易さのため、同様の構成の部分については一部符号を省略している（以下の他の図についても同じ。）。 FIG. 1 is a perspective view schematically showing a part of the magnetic recording medium 10. FIG. 2 is a diagram schematically showing a cross section along II-II shown in FIG. In FIG. 1 and FIG. 2, for ease of viewing, some reference numerals are omitted for parts having the same configuration (the same applies to the other figures below).
　図１及び図２に示したように、磁気記録媒体１０は、ビットパターンドメディア型の磁気記録媒体である。すなわち、磁気記録媒体１０は基材層１と該基材層１上に形成された磁気記録層２を備えており、該磁気記録層２には強磁性体で構成された強磁性部３と常磁性体で構成された常磁性部４とが所定の規則によって層面方向に配列されている。 As shown in FIGS. 1 and 2, the magnetic recording medium 10 is a bit patterned media type magnetic recording medium. That is, the magnetic recording medium 10 includes a base material layer 1 and a magnetic recording layer 2 formed on the base material layer 1, and the magnetic recording layer 2 includes a ferromagnetic portion 3 made of a ferromagnetic material, and Paramagnetic portions 4 made of a paramagnetic material are arranged in the layer surface direction according to a predetermined rule.
　基材層１には、公知の磁気記録媒体に使用可能な基板を特に限定することなく用いることができる。基材層１は、例えば、結晶質ガラス基板、表面酸化膜（例えばシリコン酸化膜）を有するシリコン基板、ＳｉＣ基板、カーボン基板、セラミック基板などで構成することができる。また、基材層１の厚さは特に限定されず、公知の磁気記録媒体と同様とすることができる。基材層１の厚さは、例えば、０．６３５ｍｍ以上１．２７ｍｍ以下とすることができる。 For the base material layer 1, a substrate that can be used for a known magnetic recording medium can be used without any particular limitation. The base material layer 1 can be composed of, for example, a crystalline glass substrate, a silicon substrate having a surface oxide film (for example, a silicon oxide film), a SiC substrate, a carbon substrate, a ceramic substrate, or the like. Moreover, the thickness of the base material layer 1 is not specifically limited, It can be made the same as that of a well-known magnetic recording medium. The thickness of the base material layer 1 can be 0.635 mm or more and 1.27 mm or less, for example.
　磁気記録層２は、所定の規則に従って配列された強磁性部３及び常磁性部４を備えている。ここで「所定の規則」とは、公知のＢＰＭと同様とすることができる。例えば、平面視（層面の法線方向から見ること。以下、同じ。）において、強磁性部３を四角形として、その一辺を４ｎｍ以上１５ｎｍ以下とすることが好ましい。また、平面視において隣り合う強磁性部３同士の間隔（常磁性部４幅）は、１ｎｍ以上１０ｎｍ以下とすることが好ましい。本発明によれば、後述するように微細なビットパターンを正確に作製することが容易である。ビットパターンを微細にすることによって、磁気記録媒体１０の記録密度を高めやすくなる。また、磁気記録層２の厚さは特に限定されず、公知のＢＰＭと同様とすることができる。磁気記録層２の厚さは、４ｎｍ以上１０ｎｍ以下であることが好ましい。 The magnetic recording layer 2 includes a ferromagnetic portion 3 and a paramagnetic portion 4 arranged according to a predetermined rule. Here, the “predetermined rule” can be the same as the known BPM. For example, in a plan view (viewed from the normal direction of the layer surface; hereinafter the same), it is preferable that the ferromagnetic portion 3 has a quadrangular shape and one side thereof is 4 nm or more and 15 nm or less. Moreover, it is preferable that the space | interval (paramagnetic part 4 width | variety) between the ferromagnetic parts 3 adjacent in planar view shall be 1 nm or more and 10 nm or less. According to the present invention, it is easy to accurately produce a fine bit pattern as will be described later. By making the bit pattern fine, the recording density of the magnetic recording medium 10 can be easily increased. The thickness of the magnetic recording layer 2 is not particularly limited and can be the same as that of a known BPM. The thickness of the magnetic recording layer 2 is preferably 4 nm or more and 10 nm or less.
　強磁性部３は、飽和磁化が０．３７［Ｗｂ／ｍ２］以上１．３８［Ｗｂ／ｍ２］以下の強磁性を有する合金を含んで構成されており、常磁性部４は、飽和磁化が０［Ｗｂ／ｍ２］以上０．８８［Ｗｂ／ｍ２］以下の常磁性を有する合金を含んで構成されている。また、強磁性部３に含まれる強磁性を有する合金の飽和磁化と常磁性部４に含まれる常磁性を有する合金の飽和磁化との差は、０．１０［Ｗｂ/ｍ２］以上である。なお、強磁性部３に含まれる合金の飽和磁化は０．７５［Ｗｂ／ｍ２］以上１．３８［Ｗｂ／ｍ２］以下であることが好ましく、常磁性部４に含まれる合金の飽和磁化は０［Ｗｂ／ｍ２］以上０．３８［Ｗｂ／ｍ２］以下であることが好ましく、両者の飽和磁化の差は０．３７［Ｗｂ/ｍ２］以上であることが好ましい。 The ferromagnetic part 3 includes an alloy having ferromagnetism with a saturation magnetization of 0.37 [Wb / m 2 ] or more and 1.38 [Wb / m 2 ] or less, and the paramagnetic part 4 is saturated. It is configured to include a paramagnetic alloy having a magnetization of 0 [Wb / m 2 ] or more and 0.88 [Wb / m 2 ] or less. Further, the difference between the saturation magnetization of the ferromagnetic alloy contained in the ferromagnetic part 3 and the saturation magnetization of the paramagnetic alloy contained in the paramagnetic part 4 is 0.10 [Wb / m 2 ] or more. . The saturation magnetization of the alloy included in the ferromagnetic portion 3 is preferably 0.75 [Wb / m 2 ] or more and 1.38 [Wb / m 2 ] or less, and the saturation of the alloy included in the paramagnetic portion 4 is preferable. The magnetization is preferably 0 [Wb / m 2 ] or more and 0.38 [Wb / m 2 ] or less, and the difference between the saturation magnetizations is preferably 0.37 [Wb / m 2 ] or more.
　後述するように、磁気記録層２を作製する際、同一組成の薄膜を形成した後、該薄膜の一部において合金の組成は変化させずに結晶構造を変化させることによって、強磁性部３と常磁性部４とに分けられる。すなわち、強磁性部３に含まれる合金、及び常磁性部４に含まれる合金は、組成が略同一である。ここで「組成が略同一」とは、全く同一の組成である場合に限定されず、後述するようにしてイオンを照射して常磁性部４を形成する際等に、強磁性部３を構成する合金の組成と常磁性部４を構成する合金の組成とが僅かに異なる場合も含む概念であり、具体的には９７ａｔ％以上同一であることを意味する。強磁性部３に含まれる合金、及び常磁性部４に含まれる合金の組成は下記（１）式又は（２）式で表わされる。
    （Ｆｅ１－ｘＭ１ ｘ）Ｐｔ　　（１）
（ただし、上記（１）式において、Ｍ１はＭｎ又はＮｂであり、ｘは、Ｌ１０規則構造での飽和磁化が０．３７［Ｗｂ／ｍ２］以上１．３８［Ｗｂ／ｍ２］以下となり、Ａ１不規則構造での飽和磁化が０［Ｗｂ／ｍ２］以上０．８８［Ｗｂ／ｍ２］以下となり、両者の飽和磁化の差が０．１０［Ｗｂ/ｍ２］以上となる値である。）
    Ｆｅ（Ｐｔ１－ｙＭ２ ｙ）　　（２）
（ただし、上記（２）式において、Ｍ２はＲｕ、Ｒｈ、Ｏｓ、又はＩｒのいずれかであり、ｙは、Ｌ１０規則構造での飽和磁化が０．３７［Ｗｂ／ｍ２］以上１．３８［Ｗｂ／ｍ２］以下となり、Ａ１不規則構造での飽和磁化が０［Ｗｂ／ｍ２］以上０．８８［Ｗｂ／ｍ２］以下となり、両者の飽和磁化の差が０．１０［Ｗｂ/ｍ２］以上となる値である。） As will be described later, when forming the magnetic recording layer 2, after forming a thin film of the same composition, by changing the crystal structure without changing the alloy composition in a part of the thin film, It is divided into a paramagnetic part 4. That is, the alloy contained in the ferromagnetic part 3 and the alloy contained in the paramagnetic part 4 have substantially the same composition. Here, “substantially the same composition” is not limited to the case where the compositions are exactly the same, and the ferromagnetic portion 3 is formed when the paramagnetic portion 4 is formed by irradiating ions as described later. This is a concept that includes a case where the composition of the alloy to be formed and the composition of the alloy constituting the paramagnetic portion 4 are slightly different, and specifically means that they are the same at 97 at% or more. The composition of the alloy contained in the ferromagnetic part 3 and the alloy contained in the paramagnetic part 4 is represented by the following formula (1) or (2).
(Fe 1-x M 1 x ) Pt (1)
(However, in the above formula (1), M 1 is Mn or Nb, and x is a saturation magnetization in the L1 0 ordered structure of 0.37 [Wb / m 2 ] or more and 1.38 [Wb / m 2 ]. The saturation magnetization in the A1 irregular structure is 0 [Wb / m 2 ] or more and 0.88 [Wb / m 2 ] or less, and the difference between the saturation magnetizations is 0.10 [Wb / m 2 ] or more. Value.)
Fe (Pt 1-y M 2 y ) (2)
(However, in the above formula (2), M 2 is any one of Ru, Rh, Os, and Ir, and y is a saturation magnetization in the L1 0 ordered structure of 0.37 [Wb / m 2 ] or more 1 .38 [Wb / m 2 ] or less, the saturation magnetization in the A1 disordered structure is 0 [Wb / m 2 ] or more and 0.88 [Wb / m 2 ] or less, and the difference between the saturation magnetizations is 0.10. (It is a value that is equal to or greater than [Wb / m 2 ].)
　上記（１）式を満たす合金として、例えばＭ１がＭｎである場合、ｘは、０．３＜ｘ＜０．５４であり、好ましくは０．５＜ｘ＜０．５４であり、最も好ましくはｘが約０．５２である。 As an alloy satisfying the above formula (1), for example, when M 1 is Mn, x is 0.3 <x <0.54, preferably 0.5 <x <0.54, and most preferably X is about 0.52.
　磁気記録層２を作製する際、同一組成の薄膜を形成した後、該薄膜の一部において合金の組成は変化させずに結晶構造を変化させることによって、強磁性部３と常磁性部４とに分けられる。このとき、具体的には、Ｌ１０規則構造を有するＦｅＰｔ系合金の薄膜を形成した後、該薄膜の一部においてＬ１０規則構造をＡ１不規則構造へと変化させ、結晶構造を変化させない部分が強磁性部３となり、Ａ１不規則構造へと変化させた部分が常磁性部４となる。磁気記録媒体１０を記録密度が高い磁気記録媒体とする観点からは、強磁性部３に含まれる合金の磁気異方性を高めることが好ましい。そのためには上記Ｌ１０規則構造を有するＦｅＰｔ系合金の薄膜に高［００１］配向性と高Ｌ１０規則度とを備えさせることが好ましい。すなわち、強磁性部３に含まれるＦｅＰｔ系合金を構成する結晶の（００１）面が、磁気記録層２の表面に対して平行であり、［００１］方向が、磁気記録層２の表面に対して垂直方向に向いていることが好ましい。上記のように高［００１］配向性と高Ｌ１０規則度とを実現するためには、特定の金属酸化物を所定量添加することが好ましい。当該酸化物の種類や添加量については、磁気記録媒体１０の製造方法を説明する際に説明する。 When the magnetic recording layer 2 is manufactured, after forming a thin film having the same composition, the ferromagnetic structure 3 and the paramagnetic part 4 are obtained by changing the crystal structure without changing the alloy composition in a part of the thin film. It is divided into. Part this time, specifically, after forming a thin film of FePt-based alloy having an L1 0 ordered structure, in which the L1 0 ordered structure in some of the thin film is changed into A1 disordered structure, does not change the crystal structure Becomes the ferromagnetic part 3, and the part changed to the A1 irregular structure becomes the paramagnetic part 4. From the viewpoint of making the magnetic recording medium 10 a magnetic recording medium having a high recording density, it is preferable to increase the magnetic anisotropy of the alloy contained in the ferromagnetic portion 3. For this purpose, it is preferable to provide the FePt alloy thin film having the L1 0 ordered structure with high [001] orientation and high L1 0 order . That is, the (001) plane of the crystal constituting the FePt alloy included in the ferromagnetic portion 3 is parallel to the surface of the magnetic recording layer 2, and the [001] direction is relative to the surface of the magnetic recording layer 2. It is preferable to face in the vertical direction. To achieve a high [001] orientation and high L1 0 order parameter as described above, it is preferable to add a predetermined amount of a specific metal oxide. The type and amount of the oxide will be described when the method for manufacturing the magnetic recording medium 10 is described.
　これまでに説明したように、強磁性部３は高い磁気異方性を有する合金で構成される。したがって、磁気記録層２の記録密度を高めやすい。また、磁気記録層２は、組成が同一の薄膜を形成した後に該薄膜の一部にイオンを照射して結晶構造を変化させることによって作製できる。よって、微細なビットパターンの形成が容易であり、磁気記録層２の記録密度を高めやすい。また、磁気記録層２を作製する際には最終的に表面を研磨したり加熱したりする必要がない。したがって、上述した従来のトップダウン方式で製造される磁気記録媒体に比べて磁気記録媒体１０は容易に製造可能であり、製品品質および歩留まりを向上させやすくなるので、製造コストを下げることも容易である。 As described above, the ferromagnetic portion 3 is made of an alloy having high magnetic anisotropy. Therefore, it is easy to increase the recording density of the magnetic recording layer 2. The magnetic recording layer 2 can be produced by forming a thin film having the same composition and then irradiating a part of the thin film with ions to change the crystal structure. Therefore, it is easy to form a fine bit pattern and to easily increase the recording density of the magnetic recording layer 2. Further, when the magnetic recording layer 2 is manufactured, it is not necessary to finally polish or heat the surface. Therefore, the magnetic recording medium 10 can be easily manufactured as compared with the conventional magnetic recording medium manufactured by the top-down method described above, and the product quality and the yield are easily improved, so that the manufacturing cost can be easily reduced. is there.
　なお、図１及び図２には、基材層１及び磁気記録層２のみ示してその他の層を省略しているが、磁気記録媒体１０には通常の磁気記録媒体に備えられる他の層が備えられていてもよい。当該他の層としては、例えば、基材層１と磁気記録層２と間に備えられる下地層や、磁気記録層２上に形成される保護層や、磁気記録媒体１０の最表面に形成される潤滑剤層等が挙げられる。下地層は、例えば軟磁性を示すＮｉＦｅの薄膜によって構成することができる。保護層は、例えばＤＬＣ（ダイヤモンドライクカーボン）や水素化カーボン等の薄膜によって構成することができる。潤滑剤層は、例えばフルオロカーボン樹脂等の薄膜によって構成することができる。 In FIGS. 1 and 2, only the base layer 1 and the magnetic recording layer 2 are shown and other layers are omitted. However, the magnetic recording medium 10 includes other layers provided in a normal magnetic recording medium. It may be provided. Examples of the other layer include an underlayer provided between the base material layer 1 and the magnetic recording layer 2, a protective layer formed on the magnetic recording layer 2, and the outermost surface of the magnetic recording medium 10. And a lubricant layer. The underlayer can be formed of, for example, a NiFe thin film exhibiting soft magnetism. The protective layer can be formed of a thin film such as DLC (diamond-like carbon) or hydrogenated carbon. The lubricant layer can be formed of a thin film such as a fluorocarbon resin.
　これまでに説明した磁気記録媒体１０は、以下に説明するようにして製造することができる。図３は磁気記録媒体１０の製造方法Ｓ１０を説明するフロー図である。また、図４は磁気記録媒体１０の製造方法を説明する断面図である。 The magnetic recording medium 10 described so far can be manufactured as described below. FIG. 3 is a flowchart for explaining the manufacturing method S10 of the magnetic recording medium 10. FIG. 4 is a cross-sectional view illustrating a method for manufacturing the magnetic recording medium 10.
　図３に示したように、製造方法Ｓ１０は成膜工程Ｓ１、マスク配置工程Ｓ２、イオン照射工程Ｓ３、及びマスク除去工程Ｓ４を有している。以下、これらの工程について説明する。 As shown in FIG. 3, the manufacturing method S10 includes a film forming step S1, a mask arranging step S2, an ion irradiation step S3, and a mask removing step S4. Hereinafter, these steps will be described.
　成膜工程Ｓ１は、図４（Ａ）に示したように、基材層１に用いる基板を用意し、該基板上に磁気記録層２の前駆体となる前駆体層２’を成膜する工程である。前駆体層２’は、Ｌ１０規則構造を有するとともに組成が上記（１）式又は（２）式で表わされ、且つ飽和磁化が０．３７［Ｗｂ／ｍ２］以上１．３８［Ｗｂ／ｍ２］以下の強磁性を有する合金を含む薄膜である。後のイオン照射工程Ｓ３において、前駆体層２’のうちイオンが照射された部分は常磁性部４となり、イオンが照射されなかった部分は強磁性部３となる。よって、前駆体層２’は、強磁性部３に適した材料で構成される。例えば、前駆体層２’は、高［００１］配向性と高Ｌ１０規則度とを備えた合金を含むことが好ましい。すなわち、前駆体層２’に含まれる合金を構成する結晶の（００１）面が、前駆体層２’の表面に対して平行であり、［００１］方向が、前駆体層２’の表面に対して垂直方向に向いていることが好ましい。ＦｅＰｔ系合金の薄膜において高［００１］配向性と高Ｌ１０規則度とを備えさせるためには、ＦｅＰｔ系合金に特定の金属酸化物を所定量添加して成膜した後、加熱処理を施すことが好ましい。すなわち、成膜工程Ｓ１は、基材層１上にＦｅＰｔ系合金と、後に説明する金属酸化物とを含有した薄膜を成膜した後、該薄膜を加熱する工程とすることが好ましい。 In the film forming step S1, as shown in FIG. 4A, a substrate used for the base material layer 1 is prepared, and a precursor layer 2 ′ serving as a precursor of the magnetic recording layer 2 is formed on the substrate. It is a process. The precursor layer 2 ′ has an L1 0 ordered structure, the composition is represented by the above formula (1) or (2), and the saturation magnetization is 0.37 [Wb / m 2 ] or more and 1.38 [Wb]. / M 2 ] The following is a thin film containing an alloy having ferromagnetism. In the subsequent ion irradiation step S3, the part irradiated with ions in the precursor layer 2 ′ becomes the paramagnetic part 4, and the part not irradiated with ions becomes the ferromagnetic part 3. Therefore, the precursor layer 2 ′ is made of a material suitable for the ferromagnetic portion 3. For example, the precursor layer 2 'preferably includes a high [001] orientation and high L1 0 order parameter and the provided alloy. That is, the (001) plane of the crystal constituting the alloy contained in the precursor layer 2 ′ is parallel to the surface of the precursor layer 2 ′, and the [001] direction is on the surface of the precursor layer 2 ′. On the other hand, it is preferably oriented in the vertical direction. In order to provide high [001] orientation and high L1 0 order in a thin film of FePt-based alloy, a predetermined amount of a specific metal oxide is added to the FePt-based alloy, followed by heat treatment. It is preferable. That is, the film forming step S1 is preferably a step of heating a thin film containing a FePt-based alloy and a metal oxide described later on the base material layer 1 and then heating the thin film.
　ＦｅＰｔ系合金と金属酸化物とを含有した前駆体層２’を基材層１上に形成する方法は特に限定されない。例えば、ＦｅＰｔ系合金を構成する金属及び金属酸化物をそれぞれターゲットとして同時スパッタリング成膜する方法が考えられる。ＦｅＰｔ系合金を構成する金属にかえてＦｅＰｔ系合金をターゲットとしてスパッタリング成膜することもできる。あらかじめＦｅＰｔ系合金に金属酸化物を混合した材料をターゲットとしてスパッタリング成膜してもよい。なお、ＦｅＰｔ系合金をターゲットとしてスパッタリング成膜する場合は、ＦｅＰｔ系合金の組成比を固定することが容易である。 The method for forming the precursor layer 2 ′ containing the FePt-based alloy and the metal oxide on the base material layer 1 is not particularly limited. For example, a method of simultaneous sputtering film formation using a metal and a metal oxide constituting an FePt alloy as targets can be considered. Sputtering film formation can also be performed using an FePt alloy as a target instead of the metal constituting the FePt alloy. Sputter deposition may be performed using a material in which a metal oxide is previously mixed with an FePt-based alloy as a target. In addition, when forming a sputtering film using an FePt alloy as a target, it is easy to fix the composition ratio of the FePt alloy.
　成膜工程Ｓ１で得られる前駆体層２’中の（Ｆｅ１－ｘＭ１ ｘ）とＰｔとの含有比率、又は、Ｆｅと（Ｐｔ１－ｙＭ２ ｙ）との含有比率は、４０～６０：６０～４０程度であることが好ましい。当該含有比率を上記範囲とすることによって、ＦｅＰｔ系合金のＬ１０規則度を高めやすくなる。 The content ratio of (Fe 1-x M 1 x ) and Pt in the precursor layer 2 ′ obtained in the film forming step S1 or the content ratio of Fe to (Pt 1-y M 2 y ) is 40 It is preferably about 60:60 to 40. The content ratio in the above range, it becomes easy enhance L1 0 degree of order of FePt-based alloy.
　本発明者らは、ＦｅＰｔ系合金に特定の金属酸化物を添加するとともに急速加熱することによって、高［００１］配向性と高Ｌ１０規則度とを有する薄膜が得られることを見出している。室温でスパッタ成膜したＦｅＰｔ系合金の膜は、ｆｃｃ微細結晶の集合体である。このＦｅＰｔ系合金膜を数百℃に加熱すると、該膜が再結晶化し、粒成長を起こす。ｆｃｃ相は準安定相であり、Ｌ１０相は熱平衡相であるため、原子拡散が十分に起これば、この再結晶化過程において、ｆｃｃ相からＬ１０相に変態する。さらに再結晶化過程において、微結晶粒子間に膜面内方向に引っ張り応力が作用すると、歪みを緩和するために、Ｌ１０相は膜面垂直方向に［００１］配向する。この引っ張り応力は時間の経過とともに次第に緩和されるが、急速加熱熱処理によって引っ張り応力が緩和しない間に再結晶化プロセスを進行させれば、高［００１］配向性と高Ｌ１０規則度とを有するＦｅＰｔ系合金薄膜を形成できる。 The present inventors have found that by rapidly heating with adding a specific metal oxide in the FePt alloy, a thin film having a high [001] orientation and high L1 0 degree of order is obtained. The FePt alloy film formed by sputtering at room temperature is an aggregate of fcc fine crystals. When this FePt alloy film is heated to several hundred degrees Celsius, the film is recrystallized to cause grain growth. Since the fcc phase is a metastable phase and the L1 0 phase is a thermal equilibrium phase, if sufficient atomic diffusion occurs, the fcc phase is transformed into the L1 0 phase in this recrystallization process. Further, in the recrystallization process, when a tensile stress acts between the microcrystalline grains in the in-plane direction, the L1 0 phase is [001] oriented in the direction perpendicular to the film plane in order to relax the strain. This tensile stress is gradually relieved with the passage of time. However, if the recrystallization process proceeds while the tensile stress is not relieved by rapid thermal annealing, the tensile stress has high [001] orientation and high L1 0 order. An FePt-based alloy thin film can be formed.
　ところで、金属酸化物をスパッタ成膜すると、スパッタによって乖離した金属原子、酸素原子、酸化物分子が基板上に飛来する。このとき、基板を室温として金属酸化物とＦｅＰｔ系合金とを同時にスパッタで成膜すれば、形成された薄膜は金属原子、酸素原子、金属酸化物分子、及びＦｅＰｔ系合金の混合物になる。この薄膜を加熱すると、金属原子は母相のＦｅＰｔ系合金中を移動し、酸素原子と再結合して酸化物を形成する。もしもスパッタ時に添加された金属原子の拡散係数が低温で十分大きければ、低温でも該金属原子はＦｅＰｔ系合金中を移動しやすくなるため、低温で再結晶化過程が誘起される。また、再結合した酸化物は、上述したように、加熱時の薄膜の結晶成長過程を制御することによって高［００１］配向性を有する膜の形成を促進する。しかしながら、添加する金属原子の酸化物生成自由エネルギーがＦｅの酸化物生成自由エネルギーよりも高ければ、Ｆｅ酸化物が形成され、添加した金属原子がＦｅＰｔ系合金中に固溶もしくは粒界析出する。そのため、Ｌ１０構造を有するＦｅＰｔ系合金の特性が劣化する。一方、酸化物生成自由エネルギーが低く、酸化物の安定性が高すぎると、スパッタ時の金属原子の乖離が十分に起こらず、拡散を促進することができない。このような観点から、添加する金属酸化物を構成する金属は、室温での酸化物生成自由エネルギーΔＧｆ°が－８５０ｋＪ/ｍｏｌ以上、－５００ｋＪ/ｍｏｌ以下であることが好ましい。 By the way, when metal oxide is formed by sputtering, metal atoms, oxygen atoms, and oxide molecules separated by sputtering fly onto the substrate. At this time, if a metal oxide and an FePt alloy are simultaneously formed by sputtering with the substrate at room temperature, the formed thin film becomes a mixture of metal atoms, oxygen atoms, metal oxide molecules, and FePt alloys. When this thin film is heated, the metal atoms move in the FePt alloy of the parent phase and recombine with oxygen atoms to form oxides. If the diffusion coefficient of the metal atoms added at the time of sputtering is sufficiently large at low temperatures, the metal atoms are likely to move through the FePt alloy even at low temperatures, so that a recrystallization process is induced at low temperatures. Further, as described above, the recombined oxide promotes the formation of a film having a high [001] orientation by controlling the crystal growth process of the thin film during heating. However, if the oxide formation free energy of the metal atom to be added is higher than the oxide formation free energy of Fe, an Fe oxide is formed, and the added metal atom is dissolved or precipitated at the grain boundary in the FePt alloy. Therefore, the characteristics of FePt-based alloy having an L1 0 structure is deteriorated. On the other hand, if the free energy for oxide formation is low and the stability of the oxide is too high, the metal atoms are not sufficiently separated during sputtering, and diffusion cannot be promoted. From such a viewpoint, the metal constituting the metal oxide to be added preferably has an oxide formation free energy ΔG f ° at room temperature of −850 kJ / mol or more and −500 kJ / mol or less.
　上記酸化物生成自由エネルギーの範囲を満足する金属酸化物としては、ＳｉＯ２、ＺｎＯ、Ｎａ２Ｏ等を挙げられる。なお、これらの酸化物の中で使いやすさや安全性の観点からは、ＳｉＯ２、ＺｎＯが好ましい。 Examples of the metal oxide that satisfies the range of free energy for generating the oxide include SiO 2 , ZnO, and Na 2 O. Of these oxides, SiO 2 and ZnO are preferable from the viewpoint of ease of use and safety.
　また、本発明に用いることができる所定の金属酸化物を構成する金属は、１００℃以上５００℃以下の融点を持つ金属であることが好ましい。磁気記録媒体としての実用化を考慮すれば、１００℃以上５００℃以下程度の低温度でＬ１０規則化を進行させるとともに、高［００１］配向性を達成することが望ましいからである。合金の拡散係数は、該合金を構成する元素の拡散係数の和によって与えられるが、最も大きな拡散係数を持つ元素が拡散過程を支配する。金属元素の拡散係数は、概ね融点で概算することができる。Ｆｅ、Ｐｔの融点は１５００℃以上であり、室温近傍での拡散係数は低い。したがって、１００℃以上５００℃以下程度の温度で拡散を起こすためには、１００℃以上５００℃以下の融点を持つ物質を添加することが必要である。 The metal constituting the predetermined metal oxide that can be used in the present invention is preferably a metal having a melting point of 100 ° C. or higher and 500 ° C. or lower. Considering the practical use as a magnetic recording medium, along with the progress of the L1 0 ordered at a low temperature at 100 ° C. or higher 500 ° C. or less, it is because it is desirable to achieve a high [001] orientation. The diffusion coefficient of an alloy is given by the sum of the diffusion coefficients of the elements constituting the alloy, but the element having the largest diffusion coefficient dominates the diffusion process. The diffusion coefficient of the metal element can be roughly estimated by the melting point. The melting point of Fe and Pt is 1500 ° C. or higher, and the diffusion coefficient near room temperature is low. Therefore, in order to cause diffusion at a temperature of about 100 ° C. to 500 ° C., it is necessary to add a substance having a melting point of 100 ° C. to 500 ° C.
　ＳｉＯ２、ＺｎＯ及びＮａ２Ｏのうち、上記融点の範囲を満足する金属酸化物としては、ＺｎＯが挙げられる。 Among SiO 2 , ZnO, and Na 2 O, ZnO is an example of a metal oxide that satisfies the above melting point range.
　金属酸化物の添加量は、ＦｅＰｔ系合金と添加する金属酸化物の合計量に対して、２．５体積％以上１２．５体積％以下であることが好ましい。金属酸化物の添加量が少なすぎても多すぎても、加熱処理した後に得られるＦｅＰｔ系合金の［００１］配向性が低く、磁気異方性が劣る傾向にある。 The addition amount of the metal oxide is preferably 2.5% by volume or more and 12.5% by volume or less with respect to the total amount of the FePt alloy and the metal oxide to be added. If the addition amount of the metal oxide is too small or too large, the [001] orientation of the FePt-based alloy obtained after the heat treatment tends to be low and the magnetic anisotropy tends to be inferior.
　上記のようにして成膜した後、加熱処理を行う。加熱処理を行うことによって、前駆体層２’に高［００１］配向性、および高Ｌ１０規則度を備えさせることができる。当該加熱処理における昇温速度は３０℃／秒以上であることが好ましく、１００℃／秒以上であることがより好ましい。昇温速度を速くすると、ＦｅＰｔ系合金が高［００１］配向性、および高Ｌ１０規則度を有するようになり、磁気異方性が向上する。また、加熱温度は、４００℃以上５００℃以下であることが好ましい。この温度が低すぎればＦｅＰｔ系合金の［００１］配向性が低下する傾向にあり、高すぎれば生産性の観点から好ましくない。 After film formation as described above, heat treatment is performed. By performing the heat treatment, it is possible to equip the precursor layer 2 'high [001] orientation, and the high L1 0 degree of order. The temperature increase rate in the heat treatment is preferably 30 ° C./second or more, and more preferably 100 ° C./second or more. A fast heating rate, will have an FePt-based alloy high [001] orientation, and the high L1 0 order parameter, magnetic anisotropy is improved. Moreover, it is preferable that heating temperature is 400 degreeC or more and 500 degrees C or less. If this temperature is too low, the [001] orientation of the FePt-based alloy tends to decrease, and if it is too high, it is not preferable from the viewpoint of productivity.
　次にマスク配置工程Ｓ２について説明する。マスク配置工程Ｓ２は、図４（Ｂ）に示したように、後のイオン照射工程Ｓ３において、イオンが照射される部分、すなわち常磁性部４とされる部分以外にイオンが照射されないように、マスク５を配置する工程である。マスク５を構成する材料は、イオン照射工程Ｓ３において照射するイオンを透過させず、且つイオン照射工程Ｓ３の環境に耐えうるものであれば特に限定されない。マスク５を構成する材料の具体例としては、ＺＥＰ５２０Ａ（日本ゼオン株式会社製、電子ビーム用レジスト）やナノインプリント用の樹脂等の有機物が挙げられる。 Next, the mask placement step S2 will be described. In the mask placement step S2, as shown in FIG. 4B, in the subsequent ion irradiation step S3, ions are not irradiated except for the portion irradiated with ions, that is, the portion to be the paramagnetic portion 4. This is a step of disposing the mask 5. The material which comprises the mask 5 will not be specifically limited if the ion irradiated in ion irradiation process S3 does not permeate | transmit, and can endure the environment of ion irradiation process S3. Specific examples of the material constituting the mask 5 include organic substances such as ZEP520A (manufactured by Zeon Corporation, electron beam resist) and nanoimprint resin.
　次にイオン照射工程Ｓ３について説明する。イオン照射工程Ｓ３は、成膜工程Ｓ１で形成した前駆体層２’に任意のイオンを照射する工程である。本発明者らは、これまでの研究によって数ｋｅＶに加速された任意のイオンを、Ｌ１０規則構造を有する薄膜に対して０．１０～１．０ａｔ％程度照射することで、Ａ１不規則構造へと変態させることが可能であることを知見した（非特許文献５、６参照。）。また、本発明者らは、上述したように、所定のＦｅＰｔ系合金では結晶構造を変化させることによって飽和磁化が大幅に変化することを知見した。イオン照射工程Ｓ３において前駆体層２’の一部にイオンを照射することによって、イオンが照射された部分はＬ１０規則構造からＡ１不規則構造となり、常磁性部４となる。一方、前駆体層２’のうちイオンが照射されなかったマスク５の下部はＬ１０規則構造を維持して強磁性を維持し、強磁性部３となる。 Next, ion irradiation process S3 is demonstrated. The ion irradiation step S3 is a step of irradiating the precursor layer 2 ′ formed in the film forming step S1 with arbitrary ions. The present inventors irradiate a thin film having an L1 0 ordered structure with about 0.10 to 1.0 at% by irradiating an arbitrary ion accelerated to several keV by the previous research, thereby obtaining an A1 disordered structure. It has been found that it can be transformed into (see Non-Patent Documents 5 and 6). Further, as described above, the present inventors have found that the saturation magnetization changes greatly by changing the crystal structure in a predetermined FePt-based alloy. By irradiating ions to the portion of the precursor layer 2 'in the ion irradiation step S3, a portion ions are irradiated becomes A1 disordered structure from L1 0 ordered structure, a paramagnetic part 4. On the other hand, the lower portion of the mask 5 which ions are not irradiated of the precursor layer 2 'maintains the ferromagnetic maintains an L1 0 ordered structure, the ferromagnetic portion 3.
　イオン照射工程Ｓ３で用いるイオンは前駆体層２’を構成する合金の結晶構造をＬ１０規則構造からＡ１不規則構造へと変態させることができる一定以上のエネルギーを有していれば良く、イオン種は特に限定されない。イオンの照射量は、前駆体層２’のうちイオンが照射される部分、すなわち常磁性部４となる部分の０．１０ａｔ％以上２．０ａｔ％以下であることが好ましい。０．１０ａｔ％以上とすることによって、Ｌ１０規則構造をＡ１不規則構造へと変態させやすくなり、２．０ａｔ％以下とすることによって、膜表面に大きな凹凸が形成されることを抑制できる。また、照射するイオン種の具体例としては、Ｍｎ、Ｂ、Ｃｒ、Ｇａ、Ｎｂ、Ｆｅ、Ｐｔ等のイオンが挙げられる。ただし、前駆体層２’を構成する合金の組成が（Ｆｅ１－ｘＭｎｘ）Ｐｔの場合、照射するイオン種としてはＭｎイオンを用いることが好ましい。Ｍｎイオンを用いることによって、常磁性部４のＭｎイオンの濃度を上昇させて飽和磁化を減少させやすくなる。 Ions used in the ion irradiation step S3, only to have a certain level of energy can be transformed with the crystal structure of the alloy constituting the precursor layer 2 'to L1 0 ordered structure to the A1 irregularities, ion The species is not particularly limited. The ion irradiation amount is preferably 0.10 at% or more and 2.0 at% or less of the portion of the precursor layer 2 ′ that is irradiated with ions, that is, the portion that becomes the paramagnetic portion 4. By the 0.10At% or more, an L1 0 ordered structure tends to transformation into A1 disordered structure, by less 2.0 at%, it is possible to prevent the large irregularities are formed on the film surface. Specific examples of the ion species to be irradiated include ions such as Mn, B, Cr, Ga, Nb, Fe, and Pt. However, when the composition of the alloy constituting the precursor layer 2 ′ is (Fe 1-x Mn x ) Pt, it is preferable to use Mn ions as the ion species to be irradiated. By using Mn ions, the concentration of Mn ions in the paramagnetic portion 4 is increased, and the saturation magnetization is easily reduced.
　イオン照射工程Ｓ３で照射するイオンの量は少量であるため、イオン照射工程Ｓ３でのイオン照射によって磁気記録層２の表面に凹凸ができたとしても、その大きさは磁気記録媒体として用いる際に無視できる程度のものである。 Since the amount of ions irradiated in the ion irradiation step S3 is small, even if the surface of the magnetic recording layer 2 is uneven due to the ion irradiation in the ion irradiation step S3, the size of the ion recording step S3 can be reduced when used as a magnetic recording medium. It can be ignored.
　次にマスク除去工程Ｓ４について説明する。マスク除去工程Ｓ４は、マスク配置工程Ｓ２で配置したマスク５を除去する工程である。マスク５を除去する方法は、マスク５を構成する材料等に応じて適宜選択可能である。例えば、９０℃以上に保持した有機物（ジメチルスルホキシド）中で超音波洗浄を行う方法などがある。マスク除去工程Ｓ４においてマスク５を除去することによって、図４（Ｄ）に示したように、磁気記録媒体１０を得ることができる。 Next, the mask removal step S4 will be described. The mask removal step S4 is a step of removing the mask 5 arranged in the mask arrangement step S2. The method for removing the mask 5 can be appropriately selected according to the material constituting the mask 5 and the like. For example, there is a method of performing ultrasonic cleaning in an organic substance (dimethyl sulfoxide) maintained at 90 ° C. or higher. By removing the mask 5 in the mask removal step S4, the magnetic recording medium 10 can be obtained as shown in FIG.
　なお、上述したように磁気記録媒体１０は従来の磁気記録媒体と同様に基材層１及び磁気記録層２以外にさらに他の層を備えていてもよい。磁気記録媒体１０がこのような他の層を有する場合は、製造方法Ｓ１０がこれらの他の層を形成する工程をさらに有することは言うまでもない。これらの他の層を形成する方法は特に限定されず、従来の磁気記録媒体の製造方法と同様に行うことができ、例えばプラズマ気相成長法等で成膜することができる。 As described above, the magnetic recording medium 10 may further include other layers in addition to the base layer 1 and the magnetic recording layer 2 in the same manner as the conventional magnetic recording medium. When the magnetic recording medium 10 has such other layers, it goes without saying that the manufacturing method S10 further includes a step of forming these other layers. The method for forming these other layers is not particularly limited, and can be performed in the same manner as a conventional method for producing a magnetic recording medium. For example, the film can be formed by a plasma vapor deposition method or the like.
　これまでの説明では、本発明がＢＰＭに適用される形態を例示して説明したが、本発明は所定の規則に従って配列された強磁性部及び常磁性部を備えた磁気記録層を有する磁気記録媒体、およびその製造方法に適用可能である。すなわち、本発明はＤＴＭにも適用可能である。 In the description so far, the present invention has been described by exemplifying a mode applied to BPM. However, the present invention is a magnetic recording having a magnetic recording layer having a ferromagnetic portion and a paramagnetic portion arranged according to a predetermined rule. It is applicable to a medium and a manufacturing method thereof. That is, the present invention is applicable to DTM.
　上述した本発明の磁気記録媒体は、該磁気記録媒体を回転させる回転軸及びモーターや磁気記録層に対して情報を記録する、及び／又は磁気記録層から情報を読み出す、磁気ヘッド等、公知の磁気記録装置に備えられる部品と組み合わせて磁気記録装置とすることができる。 The magnetic recording medium of the present invention described above is a well-known magnetic head or the like that records information to and / or reads information from a rotating shaft and a motor or magnetic recording layer that rotates the magnetic recording medium. A magnetic recording device can be obtained by combining with components provided in the magnetic recording device.
　以下に、実施例にて本発明をさらに詳しく説明するが、本発明は実施例に限定されるものではない。なお、ここで用いる「％」は、特に断らない限り、磁気記録層（薄膜）全体に対する体積％を意味する。 Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the examples. Note that “%” used here means volume% with respect to the entire magnetic recording layer (thin film) unless otherwise specified.
　合金膜作製用マグネトロンスパッタ装置（ＳＰＭ－４０６）を用い、Ｆｅ、Ｐｔ、Ｍｎ及びＳｉＯ２をそれぞれターゲットとして、熱酸化Ｓｉ基板（Ｓｉ基板の表面がＳｉＯ２の酸化膜で覆われている基板）上に、（Ｆｅ１－ｘＭｎｘ）Ｐｔ合金にＳｉＯ２が１０ｖｏｌ％添加された、Ａ１不規則構造を有する（Ｆｅ１－ｘＭｎｘ）Ｐｔ合金の薄膜を成膜した。成膜条件は、０．５ＰａのＡｒガス下、且つ室温であった。 Using a magnetron sputtering apparatus (SPM-406) for producing an alloy film and using Fe, Pt, Mn and SiO 2 as targets, respectively, a thermally oxidized Si substrate (a substrate on which the surface of the Si substrate is covered with an oxide film of SiO 2 ) above, (Fe 1-x Mn x ) SiO 2 to Pt alloy was added 10 vol%, and a thin film of (Fe 1-x Mn x) Pt alloys with A1 disordered structure. The film forming conditions were room temperature under Ar gas of 0.5 Pa.
　次に、上記と同様にしてＡ１不規則構造を有する（Ｆｅ１－ｘＭｎｘ）Ｐｔ合金の薄膜を用意し、高速真空熱処理装置（ＲＴＡ）を用いて、真空中で上記薄膜に熱処理を施した。熱処理条件は、昇温速度が１００℃／秒、到達温度が７００℃、到達温度での保持時間が１０分間であった。その後、真空中で自然冷却することによって、Ｌ１０規則構造を有する（Ｆｅ１－ｘＭｎｘ）Ｐｔ合金の薄膜を得た。当該薄膜の膜厚は６．１２ｎｍであった。 Next, a (Fe 1-x Mn x ) Pt alloy thin film having an A1 disordered structure is prepared in the same manner as described above, and the thin film is subjected to heat treatment in a vacuum using a rapid vacuum heat treatment apparatus (RTA). did. The heat treatment conditions were a temperature rising rate of 100 ° C./second, an reached temperature of 700 ° C., and a holding time at the reached temperature of 10 minutes. Then, by natural cooling in vacuo to give a thin film of a (Fe 1-x Mn x) Pt alloy L1 0 ordered structure. The thickness of the thin film was 6.12 nm.
　上記のようにして作製したＡ１不規則構造を有する（Ｆｅ１－ｘＭｎｘ）Ｐｔ合金の薄膜、及び、Ｌ１０規則構造を有する（Ｆｅ１－ｘＭｎｘ）Ｐｔ合金の薄膜について、ｘの値と飽和磁化との関係を図７に示した。図７に示したように、ｘ＝０．５２の場合において、飽和磁化が結晶構造に依存して大きく異なっていることがわかる。この特性を利用し、ＢＰＭを製造した。詳しくは以下の通りである。 A thin film of (Fe 1-x Mn x ) Pt alloy having an A1 disordered structure and a thin film of (Fe 1-x Mn x ) Pt alloy having an L1 0 ordered structure were prepared as described above. The relationship between the value and the saturation magnetization is shown in FIG. As shown in FIG. 7, it can be seen that the saturation magnetization greatly differs depending on the crystal structure when x = 0.52. BPM was manufactured using this characteristic. Details are as follows.
　上述したようにして（Ｆｅ０．４８Ｍｎ０．５２）Ｐｔ合金薄膜を作製し、該薄膜上に微細加工マスクを配置して、３０ｋｅＶに加速されたＧａイオンを上記薄膜に０．１ａｔ％照射してビットパターンを転写した。このとき、マスクで覆われた領域はＬ１０強磁性相を保持し、マスクで覆われていない領域はイオンが照射されてＡ１常磁性相へと変態した。その後、マスクを除去して、ＢＰＭを完成させた。 A (Fe 0.48 Mn 0.52 ) Pt alloy thin film is prepared as described above, a microfabricated mask is arranged on the thin film, and the thin film is irradiated with Ga ions accelerated to 30 keV by 0.1 at%. The bit pattern was transferred. At this time, the regions covered by the masks holds an L1 0 ferromagnetic phase, a region not covered with the mask was transformed into A1 paramagnetic phase is irradiated ions. Thereafter, the mask was removed to complete the BPM.
　このように本発明によれば、記録密度を高めることが容易な磁気記録媒体を容易に製造することができた。 As described above, according to the present invention, a magnetic recording medium in which the recording density can be easily increased can be easily manufactured.
　１　基材層
　２　磁気記録層
　２’　前駆体層
　３　強磁性部
　４　常磁性部
　５　マスク
　１０　磁気記録媒体 DESCRIPTION OF SYMBOLS 1 Base material layer 2 Magnetic recording layer 2 'Precursor layer 3 Ferromagnetic part 4 Paramagnetic part 5 Mask 10 Magnetic recording medium

Claims (9)

  1. 　基材層、及び該基材層上に形成された磁気記録層を有し、
    　前記磁気記録層は所定の規則に従って配列された強磁性部及び常磁性部を備えており、
    　前記強磁性部は、飽和磁化が０．３７［Ｗｂ／ｍ２］以上１．３８［Ｗｂ／ｍ２］以下の強磁性を有する合金を含んでおり、
    　前記常磁性部は、飽和磁化が０［Ｗｂ／ｍ２］以上０．８８［Ｗｂ／ｍ２］以下の常磁性を有する合金を含んでおり、
    　前記強磁性部に含まれる前記合金の飽和磁化と、前記常磁性部に含まれる前記合金の飽和磁化との差が０．１０［Ｗｂ/ｍ２］以上であり、
    　前記強磁性部に含まれる前記合金、及び前記常磁性部に含まれる前記合金は、組成が略同一であり、且つ当該組成は下記（１）式又は（２）式で表わされ、
    　前記強磁性部に含まれる前記合金はＬ１０規則構造を有し、前記常磁性部に含まれる前記合金はＡ１不規則構造を有する、磁気記録媒体。
    　　（Ｆｅ１－ｘＭ１ ｘ）Ｐｔ　　（１）
    （ただし、上記（１）式において、Ｍ１はＭｎ又はＮｂであり、ｘは、Ｌ１０規則構造での飽和磁化が０．３７［Ｗｂ／ｍ２］以上１．３８［Ｗｂ／ｍ２］以下となり、Ａ１不規則構造での飽和磁化が０［Ｗｂ／ｍ２］以上０．８８［Ｗｂ／ｍ２］以下となり、両者の飽和磁化の差が０．１０［Ｗｂ/ｍ２］以上となる値である。）
    　　Ｆｅ（Ｐｔ１－ｙＭ２ ｙ）　　（２）
    （ただし、上記（２）式において、Ｍ２はＲｕ、Ｒｈ、Ｏｓ、又はＩｒのいずれかであり、ｙは、Ｌ１０規則構造での飽和磁化が０．３７［Ｗｂ／ｍ２］以上１．３８［Ｗｂ／ｍ２］以下となり、Ａ１不規則構造での飽和磁化が０［Ｗｂ／ｍ２］以上０．８８［Ｗｂ／ｍ２］以下となり、両者の飽和磁化の差が０．１０［Ｗｂ/ｍ２］以上となる値である。）     A substrate layer, and a magnetic recording layer formed on the substrate layer;
    The magnetic recording layer includes a ferromagnetic part and a paramagnetic part arranged according to a predetermined rule,
    The ferromagnetic part includes an alloy having ferromagnetism with a saturation magnetization of 0.37 [Wb / m 2 ] or more and 1.38 [Wb / m 2 ] or less,
    The paramagnetic part includes a paramagnetic alloy having a saturation magnetization of 0 [Wb / m 2 ] or more and 0.88 [Wb / m 2 ] or less,
    The difference between the saturation magnetization of the alloy contained in the ferromagnetic part and the saturation magnetization of the alloy contained in the paramagnetic part is 0.10 [Wb / m 2 ] or more,
    The alloy contained in the ferromagnetic part and the alloy contained in the paramagnetic part have substantially the same composition, and the composition is represented by the following formula (1) or (2):
    Wherein the alloy contained in the ferromagnetic portion has an L1 0 ordered structure, wherein the alloy contained in the paramagnetic portion has a A1 disordered structure, the magnetic recording medium.
    (Fe 1-x M 1 x ) Pt (1)
    (However, in the above formula (1), M 1 is Mn or Nb, and x is a saturation magnetization in the L1 0 ordered structure of 0.37 [Wb / m 2 ] or more and 1.38 [Wb / m 2 ]. The saturation magnetization in the A1 irregular structure is 0 [Wb / m 2 ] or more and 0.88 [Wb / m 2 ] or less, and the difference between the saturation magnetizations is 0.10 [Wb / m 2 ] or more. Value.)
    Fe (Pt 1-y M 2 y ) (2)
    (However, in the above formula (2), M 2 is any one of Ru, Rh, Os, and Ir, and y is a saturation magnetization in the L1 0 ordered structure of 0.37 [Wb / m 2 ] or more 1 .38 [Wb / m 2 ] or less, the saturation magnetization in the A1 disordered structure is 0 [Wb / m 2 ] or more and 0.88 [Wb / m 2 ] or less, and the difference between the saturation magnetizations is 0.10. (Wb / m 2 ] or more.)
  2. 　前記強磁性部に含まれる前記合金、及び前記常磁性部に含まれる前記合金の組成が（Ｆｅ１－ｘＭｎｘ）Ｐｔであり、０．３＜ｘ＜０．５４である、請求項１に記載の磁気記録媒体。 The composition of the alloy contained in the ferromagnetic part and the alloy contained in the paramagnetic part is (Fe 1-x Mn x ) Pt, and 0.3 <x <0.54. 2. A magnetic recording medium according to 1.
  3. 　前記磁気記録層が金属酸化物を含む、請求項１または２に記載の磁気記録媒体。 The magnetic recording medium according to claim 1, wherein the magnetic recording layer contains a metal oxide.
  4. 　前記強磁性部に含まれる前記合金を構成する結晶の（００１）面が、前記磁気記録層の表面に対して平行であり、［００１］方向が、前記磁気記録層の表面に対して垂直方向に向いている、請求項１乃至３のいずれかに記載の磁気記録媒体。 The (001) plane of the crystal constituting the alloy included in the ferromagnetic portion is parallel to the surface of the magnetic recording layer, and the [001] direction is a direction perpendicular to the surface of the magnetic recording layer. The magnetic recording medium according to claim 1, which is suitable for a magnetic recording medium.
  5. 　基材層、及び該基材層上に形成された磁気記録層を有し、該磁気記録層が、所定の規則に従って配列された強磁性部及び常磁性部を備えた磁気記録媒体の製造方法であって、
    　前記基材層上に、Ｌ１０規則構造を有するとともに組成が下記（１）式又は（２）式で表わされ、且つ飽和磁化が０．３７［Ｗｂ／ｍ２］以上１．３８［Ｗｂ／ｍ２］以下の強磁性を有する合金を含む薄膜を形成する、薄膜形成工程と、
    　前記薄膜の一部に任意のイオンを照射することによって、前記Ｌ１０規則構造をＡ１不規則構造へと変態させるとともに飽和磁化を０［Ｗｂ／ｍ２］以上０．８８［Ｗｂ／ｍ２］以下にするイオン照射工程と、を有し、
    　前記薄膜形成工程で形成された薄膜のうち、前記イオン照射工程でイオンを照射された部分が前記常磁性部となり、前記イオンを照射されない部分が前記強磁性部となる、磁気記録媒体の製造方法。
    　　（Ｆｅ１－ｘＭ１ ｘ）Ｐｔ　　（１）
    （ただし、上記（１）式において、Ｍ１はＭｎ又はＮｂであり、ｘは、Ｌ１０規則構造での飽和磁化が０．３７［Ｗｂ／ｍ２］以上１．３８［Ｗｂ／ｍ２］以下となり、Ａ１不規則構造での飽和磁化が０［Ｗｂ／ｍ２］以上０．８８［Ｗｂ／ｍ２］以下となり、両者の飽和磁化の差が０．１０［Ｗｂ/ｍ２］以上となる値である。）
    　　Ｆｅ（Ｐｔ１－ｙＭ２ ｙ）　　（２）
    （ただし、上記（２）式において、Ｍ２はＲｕ、Ｒｈ、Ｏｓ、又はＩｒのいずれかであり、ｙは、Ｌ１０規則構造での飽和磁化が０．３７［Ｗｂ／ｍ２］以上１．３８［Ｗｂ／ｍ２］以下となり、Ａ１不規則構造での飽和磁化が０［Ｗｂ／ｍ２］以上０．８８［Ｗｂ／ｍ２］以下となり、両者の飽和磁化の差が０．１０［Ｗｂ/ｍ２］以上となる値である。）     A method of manufacturing a magnetic recording medium having a base material layer and a magnetic recording layer formed on the base material layer, the magnetic recording layer having a ferromagnetic part and a paramagnetic part arranged according to a predetermined rule Because
    On the said base material layer, it has a L1 0 ordered structure, a composition is represented by the following (1) Formula or (2) Formula, and saturation magnetization is 0.37 [Wb / m < 2 >] or more and 1.38 [Wb]. / M 2 ] a thin film forming step of forming a thin film containing an alloy having ferromagnetism of:
    By irradiating a part of the thin film with arbitrary ions, the L1 0 ordered structure is transformed into an A1 disordered structure and the saturation magnetization is 0 [Wb / m 2 ] or more and 0.88 [Wb / m 2 ]. An ion irradiation step to be described below,
    Of the thin film formed in the thin film forming step, a portion irradiated with ions in the ion irradiation step serves as the paramagnetic portion, and a portion not irradiated with the ions serves as the ferromagnetic portion. .
    (Fe 1-x M 1 x ) Pt (1)
    (However, in the above formula (1), M 1 is Mn or Nb, and x is a saturation magnetization in the L1 0 ordered structure of 0.37 [Wb / m 2 ] or more and 1.38 [Wb / m 2 ]. The saturation magnetization in the A1 irregular structure is 0 [Wb / m 2 ] or more and 0.88 [Wb / m 2 ] or less, and the difference between the saturation magnetizations is 0.10 [Wb / m 2 ] or more. Value.)
    Fe (Pt 1-y M 2 y ) (2)
    (However, in the above formula (2), M 2 is any one of Ru, Rh, Os, and Ir, and y is a saturation magnetization in the L1 0 ordered structure of 0.37 [Wb / m 2 ] or more 1 .38 [Wb / m 2 ] or less, the saturation magnetization in the A1 disordered structure is 0 [Wb / m 2 ] or more and 0.88 [Wb / m 2 ] or less, and the difference between the saturation magnetizations is 0.10. (It is a value that is equal to or greater than [Wb / m 2 ].)
  6. 　前記薄膜形成工程で形成する薄膜に含まれる前記合金の組成が（Ｆｅ１－ｘＭｎｘ）Ｐｔであり、０．３＜ｘ＜０．５４である、請求項５に記載の磁気記録媒体の製造方法。 6. The magnetic recording medium according to claim 5, wherein the composition of the alloy contained in the thin film formed in the thin film forming step is (Fe 1-x Mn x ) Pt, and 0.3 <x <0.54. Production method.
  7. 　前記イオン照射工程において用いる前記イオンがＭｎイオンであり、該Ｍｎイオンの照射量が前記常磁性部となる部分の０．１０ａｔ％以上２．０ａｔ％以下である、請求項６に記載の磁気記録媒体の製造方法。 The magnetic recording according to claim 6, wherein the ions used in the ion irradiation step are Mn ions, and an irradiation amount of the Mn ions is 0.10 at% or more and 2.0 at% or less of a portion to be the paramagnetic part. A method for manufacturing a medium.
  8. 　前記薄膜形成工程が、前記（１）式又は（２）式で表わされる組成の合金と、金属酸化物と、を含む薄膜を形成した後、該薄膜を加熱する工程を含む、請求項５乃至７のいずれかに記載の磁気記録媒体の製造方法。 The said thin film formation process includes the process of heating this thin film, after forming the thin film containing the alloy of the composition represented by the said (1) Formula or (2) Formula, and a metal oxide. 8. A method for producing a magnetic recording medium according to any one of 7 above.
  9. 　請求項１乃至４のいずれかに記載された磁気記録媒体と、該磁気記録媒体を回転させる回転軸及びモーターと、前記磁気記録層に対して情報を記録する、及び／又は前記磁気記録層から情報を読み出す、磁気ヘッドと、を備える、磁気記録装置。 5. The magnetic recording medium according to claim 1, a rotating shaft and a motor that rotate the magnetic recording medium, information is recorded on the magnetic recording layer, and / or from the magnetic recording layer. A magnetic recording apparatus comprising: a magnetic head for reading information.
PCT/JP2013/064634 2012-06-14 2013-05-27 MAGNETIC RECORDING MEDIUM USING FERROMAGNETIC-PARAMAGNETIC PHASE TRANSITION IN FePt ALLOY WO2013187217A1 (en)

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