TWI462091B - CoFeNi alloy and sputtering target for soft magnetic film in vertical magnetic recording medium - Google Patents
CoFeNi alloy and sputtering target for soft magnetic film in vertical magnetic recording medium Download PDFInfo
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- 239000000956 alloy Substances 0.000 title claims description 54
- 229910045601 alloy Inorganic materials 0.000 title claims description 54
- 229910019233 CoFeNi Inorganic materials 0.000 title claims description 38
- 238000005477 sputtering target Methods 0.000 title claims description 9
- 229910052796 boron Inorganic materials 0.000 claims description 15
- 239000000203 mixture Substances 0.000 claims description 9
- 229910052726 zirconium Inorganic materials 0.000 claims description 8
- 230000004907 flux Effects 0.000 description 21
- 238000005260 corrosion Methods 0.000 description 11
- 230000007797 corrosion Effects 0.000 description 11
- 239000000463 material Substances 0.000 description 10
- 229910052758 niobium Inorganic materials 0.000 description 10
- 229910052735 hafnium Inorganic materials 0.000 description 7
- 229910052742 iron Inorganic materials 0.000 description 7
- 238000000034 method Methods 0.000 description 7
- 229910052715 tantalum Inorganic materials 0.000 description 7
- 229910052759 nickel Inorganic materials 0.000 description 6
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 4
- 229910052804 chromium Inorganic materials 0.000 description 4
- 229910052802 copper Inorganic materials 0.000 description 4
- 239000010949 copper Substances 0.000 description 4
- 239000011521 glass Substances 0.000 description 4
- 238000002441 X-ray diffraction Methods 0.000 description 3
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 3
- 238000004544 sputter deposition Methods 0.000 description 3
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000010791 quenching Methods 0.000 description 2
- 230000000171 quenching effect Effects 0.000 description 2
- 239000007921 spray Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 229910020598 Co Fe Inorganic materials 0.000 description 1
- 229910002519 Co-Fe Inorganic materials 0.000 description 1
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 239000002178 crystalline material Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000007373 indentation Methods 0.000 description 1
- 229910001004 magnetic alloy Inorganic materials 0.000 description 1
- 230000005415 magnetization Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
Classifications
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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
- G11B5/66—Record carriers characterised by the selection of the material comprising only the magnetic material without bonding agent the record carriers consisting of several layers
- G11B5/667—Record carriers characterised by the selection of the material comprising only the magnetic material without bonding agent the record carriers consisting of several layers including a soft magnetic layer
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C19/00—Alloys based on nickel or cobalt
- C22C19/07—Alloys based on nickel or cobalt based on cobalt
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/10—Ferrous alloys, e.g. steel alloys containing cobalt
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/10—Ferrous alloys, e.g. steel alloys containing cobalt
- C22C38/105—Ferrous alloys, e.g. steel alloys containing cobalt containing Co and Ni
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
- C23C14/22—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the process of coating
- C23C14/34—Sputtering
- C23C14/3407—Cathode assembly for sputtering apparatus, e.g. Target
- C23C14/3414—Metallurgical or chemical aspects of target preparation, e.g. casting, powder metallurgy
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- 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
- H01F10/13—Amorphous metallic alloys, e.g. glassy metals
- H01F10/131—Amorphous metallic alloys, e.g. glassy metals containing iron or nickel
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- 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
- H01F10/13—Amorphous metallic alloys, e.g. glassy metals
- H01F10/132—Amorphous metallic alloys, e.g. glassy metals containing cobalt
-
- 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
- G11B5/851—Coating a support with a magnetic layer by sputtering
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Power Engineering (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Magnetic Record Carriers (AREA)
- Physical Vapour Deposition (AREA)
- Thin Magnetic Films (AREA)
- Manufacturing Of Magnetic Record Carriers (AREA)
- Soft Magnetic Materials (AREA)
Description
本申請案係依據2009年6月10日所申請之日本國專利申請案第2009-139151號，主張優先前者，其全體之揭示內容依參照組入於本說明書中。The present application is based on the Japanese Patent Application No. 2009-139151, filed on Jun. 10, 2009, the priority of which is incorporated herein by reference.
本發明係有關用以使用來作為垂直磁性記錄媒體中之軟磁性膜層之CoFeNi系合金、及其濺鍍靶材者。The present invention relates to a CoFeNi-based alloy used as a soft magnetic film layer in a perpendicular magnetic recording medium, and a sputtering target thereof.
近年，磁性記錄技術之進步很明顯，為了驅動之大容量化，磁性記錄媒體之高記錄密度化遂進展起來。例如，可實現較以往普及之面內磁性記錄媒體更高記錄密度的垂直磁性記錄方式被實用化。所謂垂直磁性記錄方式係相對於垂直磁性記錄媒體之磁性膜中的媒體面，形成為磁化容易軸配向於垂直方向者，適用於高記錄密度之方法。繼而，在垂直磁性記錄方式中係已開發出具有提高記錄感度之磁性記錄膜層與軟磁性膜層之2層記錄媒體。此磁性記錄膜層一般使用Co Cr Pt-SiO2 系合金。In recent years, advances in magnetic recording technology have become apparent, and in order to increase the capacity of driving, the high recording density of magnetic recording media has progressed. For example, a perpendicular magnetic recording method capable of realizing a higher recording density than an in-plane magnetic recording medium popular in the past has been put into practical use. The perpendicular magnetic recording method is a method in which the magnetization is easily aligned in the vertical direction with respect to the medium surface in the magnetic film of the perpendicular magnetic recording medium, and is suitable for a high recording density. Then, in the perpendicular magnetic recording method, a two-layer recording medium having a magnetic recording film layer and a soft magnetic film layer for improving recording sensitivity has been developed. As the magnetic recording film layer, a Co Cr Pt-SiO 2 -based alloy is generally used.
另外，軟磁性膜層已知有以Co或Fe之軟磁性元素作為基材，添加可改善非晶質性之Zr、Hf、Ta、Nb及B的合金。例如，如揭示於專利文獻1之垂直磁性記錄媒體中之軟磁性膜層用合金或如揭示於專利文獻2之Co-Fe系合金濺鍍靶材及其製造方法。Further, as the soft magnetic film layer, an alloy of Zr, Hf, Ta, Nb, and B which can improve amorphous properties is known as a soft magnetic element of Co or Fe as a base material. For example, an alloy for a soft magnetic film layer disclosed in a perpendicular magnetic recording medium of Patent Document 1, or a Co-Fe-based alloy sputtering target disclosed in Patent Document 2, and a method for producing the same.
於此垂直磁性記錄媒體之軟磁性膜層中係尋求高飽和磁束密度、高非晶質性、及高耐蝕性。進一步在近年中，目的在於減輕磁性記錄媒體用磁碟與讀寫用頭之接觸所產生的光碟之損傷，於軟磁性膜層遂要求硬度起來。In the soft magnetic film layer of the perpendicular magnetic recording medium, high saturation magnetic flux density, high amorphous property, and high corrosion resistance are sought. Further, in recent years, the purpose is to reduce the damage of the optical disc caused by the contact between the magnetic recording medium and the head for reading and writing, and to require hardness in the soft magnetic film layer.
專利文獻1：特開2008-299905號公報Patent Document 1: JP-A-2008-299905
專利文獻2：特開2008-189996號公報Patent Document 2: JP-A-2008-189996
本發明人等藉由具有高飽和磁束密度、高非晶質性及高耐蝕性，且使Ta及/或Nb、與B量為特定之比率，俾可得到具有較專利文獻1所提出之合金更高硬度的合金，而得到此見識。The present inventors have obtained a alloy having a higher saturation magnetic flux density, high amorphous property, and high corrosion resistance, and a ratio of Ta and/or Nb and B to a specific ratio. This is the result of a higher hardness alloy.
因此，本發明之目的在於提供一種飽和磁束密度、非晶質性、耐蝕性及硬度優異之垂直磁性記錄媒體用軟磁性合金、用以製作此合金之薄膜的濺鍍靶材、及具有由此合金所構成之軟磁性膜層的垂直磁性記錄媒體。Accordingly, an object of the present invention is to provide a soft magnetic alloy for a perpendicular magnetic recording medium having excellent saturation magnetic flux density, amorphous property, corrosion resistance and hardness, a sputtering target for forming a film of the alloy, and the like A perpendicular magnetic recording medium of a soft magnetic film layer composed of an alloy.
若依本發明之第一態樣，可提供一種CoFeNi系合金，其係垂直磁性記錄媒體中之軟磁性膜層用CoFeNi系合金，前述CoFeNi系合金就at%含有Co+Fe+Ni：70~92%(但Ni係包含0)、Ta：1~8%、及、B：超過7%且20%以下而成，前述CoFeNi系合金之組成(at%)為滿足以下之比率者：Co/(Co+Fe+Ni)：0.1~0.9、Fe/(Co+Fe+Ni)：0.1~0.65、Ni/(Co+Fe+Ni)：0~0.35，及B/Ta：1~8。According to the first aspect of the present invention, there is provided a CoFeNi-based alloy which is a CoFeNi-based alloy for a soft magnetic film layer in a perpendicular magnetic recording medium, and the CoFeNi-based alloy contains at least Co+Fe+Ni:70~ 92% (but Ni is 0), Ta: 1 to 8%, and B: more than 7% and 20% or less. The composition (at%) of the CoFeNi-based alloy is such that the following ratio is satisfied: Co/ (Co+Fe+Ni): 0.1~0.9, Fe/(Co+Fe+Ni): 0.1~0.65, Ni/(Co+Fe+Ni): 0~0.35, and B/Ta: 1~8.
若依本發明之第二態樣，可提供一種CoFeNi系合金，其係垂直磁性記錄媒體中之軟磁性膜層用CoFeNi系合金，前述CoFeNi系合金就at%含有Co+Fe+Ni：70~92%(但Ni係包含0)、Nb+Ta：1~8%、B：超過7%且20%以下而成，前述CoFeNi系合金之組成(at%)為滿足以下之比率者：Co/(Co+Fe+Ni)：0.1~0.9、Fe/(Co+Fe+Ni)：0.1~0.65、Ni/(Co+Fe+Ni)：0~0.35，及B/(Nb+Ta)：1~8。According to the second aspect of the present invention, there is provided a CoFeNi-based alloy which is a CoFeNi-based alloy for a soft magnetic film layer in a perpendicular magnetic recording medium, and the CoFeNi-based alloy contains at least Co+Fe+Ni:70~ 92% (but Ni contains 0), Nb+Ta: 1 to 8%, and B: more than 7% and 20% or less. The composition (at%) of the CoFeNi-based alloy is such that the following ratio is satisfied: Co/ (Co+Fe+Ni): 0.1~0.9, Fe/(Co+Fe+Ni): 0.1~0.65, Ni/(Co+Fe+Ni): 0~0.35, and B/(Nb+Ta):1 ~8.
若依本發明之第三態樣，可提供一種CoFeNi系合金，其係垂直磁性記錄媒體中之軟磁性膜層用CoFeNi系合金，前述CoFeNi系合金就at%含有Co+Fe+Ni：70~92%(但Ni係包含0)、Zr+Hf+Nb+Ta：1~8%、B：超過7%且20%以下、Zr+Hf：0~不足2%，及Al+Cr：0~5%而成，前述CoFeNi系合金之組成(at%)為滿足以下之比率者：Co/(Co+Fe+Ni)：0.1~0.9、Fe/(Co+Fe+Ni)：0.1~0.65、Ni/(Co+Fe+Ni)：0~0.35、及B/(Nb+Ta)：1~8。According to the third aspect of the present invention, there is provided a CoFeNi-based alloy which is a CoFeNi-based alloy for a soft magnetic film layer in a perpendicular magnetic recording medium, and the CoFeNi-based alloy contains at least Co+Fe+Ni:70~ 92% (but Ni contains 0), Zr+Hf+Nb+Ta: 1~8%, B: more than 7% and less than 20%, Zr+Hf: 0~ less than 2%, and Al+Cr: 0~ 5%, the composition (at%) of the CoFeNi-based alloy is such that: Co / (Co + Fe + Ni): 0.1 ~ 0.9, Fe / (Co + Fe + Ni): 0.1 ~ 0.65, Ni/(Co+Fe+Ni): 0 to 0.35, and B/(Nb+Ta): 1 to 8.
若依本發明之另一態樣，可提供一種濺鍍靶材，其係由上述各態樣之CoFeNi系合金所構成。According to another aspect of the present invention, a sputtering target comprising a CoFeNi-based alloy of the above various aspects can be provided.
若依本發明之再另一態樣，可提供一種垂直磁性記錄媒體，其係具有上述各態樣之CoFeNi系合金所構成的軟磁性膜層。According to still another aspect of the present invention, a perpendicular magnetic recording medium comprising a soft magnetic film layer composed of the above-described various CoFeNi-based alloys can be provided.
以下，詳細說明有關本發明。又，只要無特別聲明，本發明所記載之百分率(%)意指原子%(at%)者。Hereinafter, the present invention will be described in detail. Further, the percentage (%) described in the present invention means an atomic % (at%) unless otherwise stated.
本發明係關於垂直磁性記錄媒體中之軟磁性膜層用CoFeNi系合金。此CoFeNi系合金就at%含有Co+Fe+Ni：70~92%(但Ni係包含0)、Ta：1~8%(第一態樣)、Nb+Ta：1~8%(第二態樣)、或Zr+Hf+Nb+Ta：1~8%(第三態樣)、及、B：超過7%且20%以下，較佳係從上述元素變成實質上(consisting essentially of)，更佳係只由上述元素所構成(consisting of)。又，第三態樣之CoFeNi系合金係可進一步含有Zr+Hf：0~不足2%及Al+Cr：0~5%。此處，即使在第一至第三之任一的態樣中，CoFeNi系合金之組成(at%)為滿足以下之比率：Co/(Co+Fe+Ni)：0.1~0.9、Fe/(Co+Fe+Ni)：0.1~0.65、Ni/(Co+Fe+Ni)：0~0.35，及B/Ta：1~8。The present invention relates to a CoFeNi-based alloy for a soft magnetic film layer in a perpendicular magnetic recording medium. This CoFeNi-based alloy contains Co+Fe+Ni: 70-92% (but Ni contains 0), Ta: 1~8% (first state), and Nb+Ta: 1~8% (second). Aspect), or Zr+Hf+Nb+Ta: 1~8% (third aspect), and B: more than 7% and less than 20%, preferably from the above element to substantially (consisting essentially of) More preferably, it consists only of the above elements. Further, the third aspect of the CoFeNi-based alloy system may further contain Zr+Hf: 0 to less than 2% and Al+Cr: 0 to 5%. Here, even in the aspect of any of the first to third aspects, the composition (at%) of the CoFeNi-based alloy satisfies the following ratio: Co/(Co+Fe+Ni): 0.1 to 0.9, Fe/( Co+Fe+Ni): 0.1~0.65, Ni/(Co+Fe+Ni): 0~0.35, and B/Ta: 1~8.
Co、Fe及Ni任一者均具有軟磁性特性之元素。Co、Fe及Ni之各元素的含量無特別限定，但宜為Co：9~80%、Fe：5~60%、Ni：0~40%，更佳係Co：25~80%、Fe：15~52%、Ni：0~10%。本發明之合金中的Co、Fe及Ni之合計量(亦即Co+Fe+Ni量)為70~92%，更佳係80~92%。若此Co+Fe+Ni量不足70%，飽和磁束密度不充分，若超過92%，反之，Zr、Hf、Ta、Nb、B之合計量變少，無法得到充分的非晶質性。Any of Co, Fe, and Ni has an element of soft magnetic properties. The content of each element of Co, Fe, and Ni is not particularly limited, but is preferably Co: 9 to 80%, Fe: 5 to 60%, Ni: 0 to 40%, and more preferably Co: 25 to 80%, Fe: 15~52%, Ni: 0~10%. The total amount of Co, Fe and Ni (i.e., the amount of Co+Fe+Ni) in the alloy of the present invention is 70 to 92%, more preferably 80 to 92%. When the amount of Co+Fe+Ni is less than 70%, the saturation magnetic flux density is insufficient, and if it exceeds 92%, the total amount of Zr, Hf, Ta, Nb, and B is reduced, and sufficient amorphous properties cannot be obtained.
若比較此等之3元素，飽和磁束密度大概依Fe>Co>Ni之順序變小，另外，耐蝕性大概依Ni>Co>Fe之順序欠缺。考量如此之飽和磁束密度與耐蝕性之均衡，Co、Fe及Ni之各量對Co+Fe+Ni之比率係在以下之範圍內：Co/(Co+Fe+Ni)：0.1~0.9，較佳係0.3~0.9，Fe/(Co+Fe+Ni)：0.1~0.65，較佳係0.2~0.55，及Ni/(Co+Fe+Ni)：0~0.35，較佳係0~0.10。When comparing these three elements, the saturation magnetic flux density is reduced in the order of Fe>Co>Ni, and the corrosion resistance is probably in the order of Ni>Co>Fe. Considering the balance between saturation magnetic flux density and corrosion resistance, the ratio of Co, Fe and Ni to Co+Fe+Ni is in the following range: Co/(Co+Fe+Ni): 0.1~0.9, Preferably, the system is 0.3 to 0.9, Fe/(Co+Fe+Ni): 0.1 to 0.65, preferably 0.2 to 0.55, and Ni/(Co+Fe+Ni): 0 to 0.35, preferably 0 to 0.10.
若Ni/(Co+Fe+Ni)超過0.35，無法得到充分的飽和磁束密度。若Fe/(Co+Fe+Ni)低於0.1，無法得到充分的飽和磁束密度。另外，若超過0.65，耐蝕性會劣化。If Ni/(Co+Fe+Ni) exceeds 0.35, a sufficient saturation magnetic flux density cannot be obtained. If Fe/(Co+Fe+Ni) is less than 0.1, a sufficient saturation magnetic flux density cannot be obtained. Moreover, if it exceeds 0.65, corrosion resistance will deteriorate.
如此地，若決定Ni/(Co+Fe+Ni)及Fe/(Co+Fe+Ni)之範圍，Co/(Co+Fe+Ni)之下限變成O之(Ni/(Co+Fe+Ni)=0.35、Fe/(Co+Fe+Ni)=0.65時)，Co為極少時，在Ni/(Fe+Ni)為0.25~0.40附近，存在飽和磁束密度變成極小之特異點。因此，使Co/(Co+Fe+Ni)之下限為0.10，另外，Co/(Co+Fe+Ni)之上限變成0.9之(Ni/(Co+Fe+Ni)=0、Fe/(Co+Fe+Ni)=0.1時)。Thus, if the range of Ni/(Co+Fe+Ni) and Fe/(Co+Fe+Ni) is determined, the lower limit of Co/(Co+Fe+Ni) becomes O (Ni/(Co+Fe+Ni) When =0.35, Fe/(Co+Fe+Ni)=0.65), when Co is extremely small, Ni/(Fe+Ni) is around 0.25 to 0.40, and there is a singular point where the saturation magnetic flux density becomes extremely small. Therefore, the lower limit of Co/(Co+Fe+Ni) is 0.10, and the upper limit of Co/(Co+Fe+Ni) becomes 0.9 (Ni/(Co+Fe+Ni)=0, Fe/(Co +Fe+Ni)=0.1).
Ta、Nb及B係在本發明之合金中，任一者均為可改善非晶質性之元素。Ta、Nb及B之各元素的含量無特別限定，宜Ta：1~8%、Nb：≦5%、B超過7%且20%以下，更佳係Ta：2~6%、Nb：0~3%、B：7.5~15%。繼而，本發明之合金中的Nb及Ta的合計量(亦即Nb+Ta量)為1~8%。Nb+Ta量不足1%，無法得到充分的非晶質性，若超過8%，無法得到充分的飽和磁束密度。B為7%以下時，無法得到充分的非晶質性，若超過20%，無法得到充分的飽和磁束密度。Ta, Nb, and B are all elements of the alloy of the present invention which can improve the amorphous property. The content of each element of Ta, Nb, and B is not particularly limited, and is preferably Ta: 1 to 8%, Nb: ≦ 5%, B is more than 7% and 20% or less, and more preferably Ta: 2 to 6%, Nb: 0 ~3%, B: 7.5~15%. Then, the total amount of Nb and Ta (that is, the amount of Nb+Ta) in the alloy of the present invention is 1 to 8%. When the amount of Nb+Ta is less than 1%, sufficient amorphous properties cannot be obtained, and if it exceeds 8%, a sufficient saturation magnetic flux density cannot be obtained. When B is 7% or less, sufficient amorphous properties cannot be obtained, and if it exceeds 20%, a sufficient saturation magnetic flux density cannot be obtained.
在本發明之合金中，B量對Ta+Nb量之比率即B/(Ta+Nb)為1~8，宜為1.5~6。若為如此之範圍內，可實現以往未看到之高硬度。高硬度化之詳細原理係不明，但在合金中之Ta原子及/或Nb原子、與B原子之結合有可能影響。此處，B/(Ta+Nb)不足1或超過8時，無法得到充分的硬度。In the alloy of the present invention, the ratio of the amount of B to the amount of Ta + Nb, that is, B / (Ta + Nb) is from 1 to 8, preferably from 1.5 to 6. If it is within such a range, high hardness which has not been seen in the past can be achieved. The detailed principle of high hardness is unknown, but the combination of Ta atoms and/or Nb atoms in the alloy and B atoms may affect. Here, when B/(Ta+Nb) is less than 1 or exceeds 8, sufficient hardness cannot be obtained.
Zr及Hf任一者均為可改善非晶質性之元素。Zr及Hf之各元素的含量無特別限定，但宜Zr：≦2%、Hf：≦1.0%。Zr、Hf、Nb及Ta之合計量(亦即Zr+Hf+Nb+Ta量)可添加1~8%，Zr及Hf之合計量(亦即Zr+Hf量)可在0~不足2%之範圍添加，此態樣相當於本發明之第三態樣。Zr+Hf+Nb+Ta量不足1%時，非晶質性不充分，若超過8%，無法得到充分的飽和磁束密度。Zr+Hf量為2%以上時，硬度會降低。Any of Zr and Hf is an element which can improve the amorphous property. The content of each element of Zr and Hf is not particularly limited, but is preferably Zr: ≦ 2%, Hf: ≦ 1.0%. The total amount of Zr, Hf, Nb and Ta (that is, the amount of Zr+Hf+Nb+Ta) can be added from 1 to 8%, and the total amount of Zr and Hf (that is, the amount of Zr+Hf) can be from 0 to less than 2%. The range is added, which is equivalent to the third aspect of the invention. When the amount of Zr+Hf+Nb+Ta is less than 1%, the amorphous property is insufficient, and if it exceeds 8%, a sufficient saturation magnetic flux density cannot be obtained. When the amount of Zr+Hf is 2% or more, the hardness is lowered.
Al及Cr在本發明之合金中為改善耐蝕性之元素。Al及Cr之各元素的含量無特別限定，但宜Al≦3%、Cr≦3%。Al及Cr之合計量(亦即Al+Cr量)係使上限為5%。若Al+Cr量超過5%，飽和磁束密度降低。Al and Cr are elements for improving corrosion resistance in the alloy of the present invention. The content of each element of Al and Cr is not particularly limited, but is preferably 3% Al and Cr 3%. The total amount of Al and Cr (i.e., the amount of Al + Cr) is such that the upper limit is 5%. If the amount of Al+Cr exceeds 5%, the saturation magnetic flux density decreases.
又，一般，在垂直磁性記錄媒體中之軟磁性膜層係濺鍍與其成分相同之成分的濺鍍靶材，成膜於玻璃基板等之上而得到。此處，藉濺鍍成膜之薄膜被急冷。然而，以下敘述之實施例及比較例係使用以單輥式之液體急冷裝置製作的急冷薄帶作為供試料。此係實際上藉濺鍍急冷成膜之薄膜中，對成分之各種特性的影響，藉液體急冷薄帶簡單地評估。Further, in general, a soft magnetic film layer in a perpendicular magnetic recording medium is obtained by sputtering a sputtering target having the same composition as that of a composition, and is formed on a glass substrate or the like. Here, the film deposited by sputtering is quenched. However, in the examples and comparative examples described below, a quenched ribbon produced by a single-roller liquid quenching apparatus was used as a sample. This system is actually evaluated by the liquid quenching ribbon by the effect of sputtering on the film formed by rapid cooling film formation.
以下，依實施例具體地說明本發明。於表1之急冷薄帶的成分所秤量之原料30g以直徑10mm長40mm左右的水冷銅鑄模在減壓之Ar中進行電弧溶解，作為急冷薄帶之熔解母材。急冷薄帶之製作條件係以單輥方式，於直徑15mm之石英管中安裝於此熔解母材，以出熱水噴嘴徑為1mm，環境氣壓61kPa、噴霧壓差69kPa、銅輥(Φ 300mm)之旋轉數為3000rpm，使銅輥與出熱水噴嘴之間隙為0.3mm而出熱水。出熱水溫度係各熔解母材之溶掉後。Hereinafter, the present invention will be specifically described by way of examples. 30 g of the raw material weighed in the components of the quenched ribbon of Table 1 was arc-dissolved in a water-cooled copper mold having a diameter of 10 mm and a length of about 40 mm, and was melted as a molten base material of the quenched ribbon. The production conditions of the quenched ribbon are attached to the molten base material in a single-roller method in a quartz tube having a diameter of 15 mm, with a nozzle diameter of 1 mm, an ambient pressure of 61 kPa, a spray pressure difference of 69 kPa, and a copper roll ( Φ 300 mm). The number of rotations was 3000 rpm, and the gap between the copper roller and the outlet nozzle was 0.3 mm to discharge hot water. The outlet hot water temperature is dissolved after each molten base material is dissolved.
如上述做法所製作之急冷薄帶作為供試材，評估以下之項目。The quenched ribbon produced by the above method was used as a test material, and the following items were evaluated.
有關15mg左右的供試材，使用VSM裝置(振動試料型磁力計)，以施加磁場1.2 MA/m(15 kOe)測定飽和磁束密度(T)。Regarding the test material of about 15 mg, the saturation magnetic flux density (T) was measured using a VSM apparatus (vibration sample type magnetometer) with an applied magnetic field of 1.2 MA/m (15 kOe).
藉X線繞射進行急冷薄帶之非晶質性的評估。一般，若測定非晶質材料之X線繞射圖型，看不到繞射譜峯，而成為非晶質特有之暈圖型(hala-pattern)。又，並非完全的非晶質時，雖可看到繞射譜峯，但與結晶材料比較，譜峯高度變低，成為半寬值(成為繞射譜峯之一半高度時的角度之寬)的大寬譜峯。此半寬值係與材料之非晶質性有相關，非晶質性愈高，繞射譜峯係有變成更寬，且半寬值變大之特徵。因此，依下述之方法而評估非晶質性。The amorphous nature of the quenched ribbon was evaluated by X-ray diffraction. In general, when the X-ray diffraction pattern of an amorphous material is measured, the diffraction peak is not seen, and it becomes a halo-pattern unique to amorphous. Further, when it is not completely amorphous, the diffraction peak can be seen, but the peak height becomes lower than that of the crystalline material, and becomes a half-width value (the width of the angle when the diffraction peak is one-half height) Large broad spectrum peak. This half-width value is related to the amorphous nature of the material, the higher the amorphousness, the wider the diffraction spectrum peak, and the larger the half-width value. Therefore, the amorphous property was evaluated by the following method.
於玻璃板以雙面膠帶貼黏供試材，以X線繞射裝置得到繞射圖型。此時，測定面係成為急冷薄帶之銅輥接觸面，使供試材貼黏於玻璃板。X線源係以Cu-kα線使掃描速度形成分速4°而測定。成為此繞射圖型之主峰的一半高度時的角度之寬進行圖像解析，求出半寬值，作為非晶質性之評估。The glass plate is adhered to the test material by double-sided tape, and the diffraction pattern is obtained by the X-ray diffraction device. At this time, the measurement surface became the contact surface of the copper roll of the quenched ribbon, and the test material was adhered to the glass plate. The X-ray source was measured by forming a scanning speed of 4° on a Cu-kα line. The image was analyzed by the angle of the angle at half the height of the main peak of the diffraction pattern, and the half-width value was obtained to evaluate the amorphousness.
於玻璃板以雙面膠帶貼黏供試材，使5%NaCl的溶液為35℃而進行曝露16小時之鹽水噴霧試驗，急冷薄帶之耐蝕性依以下之基準進行評估。The glass plate was adhered to the test piece by double-sided tape, and the 5% NaCl solution was subjected to a salt spray test for exposure for 16 hours at 35 ° C. The corrosion resistance of the quenched ribbon was evaluated according to the following criteria.
×：全面生銹×: Total rust
△：一部分生銹△: Part of the rust
○：約無生銹○: There is no rust
使急冷絲帶朝縱方向埋入樹脂，進行研磨，以維氏(Vickers)硬度計測定急冷薄帶之維氏硬度(HV)。測定荷重係以50g、n=10之平均進行評估。壓痕之尺寸為10μm左右。此等之評估試驗的結果表示於表2中。The quenched ribbon was embedded in the resin in the longitudinal direction, polished, and the Vickers hardness (HV) of the quenched ribbon was measured by a Vickers hardness meter. The measured load was evaluated by an average of 50 g and n = 10. The size of the indentation is about 10 μm. The results of these evaluation tests are shown in Table 2.
在表1中，例1~9係本發明例，例10~20係比較例。In Table 1, Examples 1 to 9 are examples of the present invention, and Examples 10 to 20 are Comparative Examples.
如表1所示般，例10係Ta、B之含量少，(Co+Fe+Ni)之含量多，且(Zr+Hf+Nb+Ta)之含量少，進一步B/(Nb+Ta)值大，故半寬值小，維氏硬度低。例11係B/(Nb+Ta)之值大，故維氏硬度低。例12係B/(Nb+Ta)之值小，故維氏硬度低。As shown in Table 1, in Example 10, the content of Ta and B was small, the content of (Co+Fe+Ni) was large, and the content of (Zr+Hf+Nb+Ta) was small, and further B/(Nb+Ta). The value is large, so the half width is small and the Vickers hardness is low. In Example 11, the value of B/(Nb+Ta) is large, so the Vickers hardness is low. In Example 12, the value of B/(Nb+Ta) was small, so the Vickers hardness was low.
例13係B之含量高且(Co+Fe+Ni)之含量少，故飽和磁束密度低。例14係(Zr+Hf+Nb+Ta)之含量高，且(Zr+Hf)之含量高，故飽和磁束密度低，維氏硬度低。例15係(Al+Cr)之含量多，故飽和磁束密度低。例16係Co/(Co+Fe+Ni)之值低，故飽和磁束密度低。In Example 13, the content of the system B was high and the content of (Co+Fe+Ni) was small, so the saturation magnetic flux density was low. In Example 14, the content of (Zr+Hf+Nb+Ta) is high, and the content of (Zr+Hf) is high, so the saturation magnetic flux density is low and the Vickers hardness is low. In Example 15, the content of (Al + Cr) was large, so the saturation magnetic flux density was low. In Example 16, the value of Co/(Co+Fe+Ni) was low, so the saturation magnetic flux density was low.
例17係Co/(Co+Fe+Ni)之值高，且Fe/(Co+Fe+Ni)之值低，故飽和磁束密度低。例18係Fe/(Co+Fe+Ni)之值高，故耐蝕性差。例19係Ni/(Co+Fe+Ni)之值高，故飽和磁束密度低。例20係Ta之含量高，且(Zr+Hf+Nb+Ta)之含量高，故飽和磁束密度低。然而，例1~9係任一者均滿足本發明之條件，故可知任一者之特性均優。In Example 17, the value of Co/(Co+Fe+Ni) was high, and the value of Fe/(Co+Fe+Ni) was low, so the saturation magnetic flux density was low. In Example 18, the value of Fe/(Co+Fe+Ni) was high, so corrosion resistance was poor. In Example 19, the value of Ni/(Co+Fe+Ni) was high, so the saturation magnetic flux density was low. In Example 20, the content of Ta was high, and the content of (Zr+Hf+Nb+Ta) was high, so the saturation magnetic flux density was low. However, any of Examples 1 to 9 satisfies the conditions of the present invention, and it is understood that either of them has excellent characteristics.
如以上般，同時添加Ta及/或Nb與B，且藉由形成特定之B/(Nb+Ta)比，可得到習知合金沒有的高硬度。藉此，可提供磁性特性、非晶質性、耐蝕性、及硬度優之合金。As described above, Ta and/or Nb and B are simultaneously added, and by forming a specific B/(Nb+Ta) ratio, high hardness which is not found in conventional alloys can be obtained. Thereby, an alloy excellent in magnetic properties, amorphousness, corrosion resistance, and hardness can be provided.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| JP2007048790A (en) * | 2005-08-05 | 2007-02-22 | Sony Corp | Storage element and memory |
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| JP2009070444A (en) * | 2007-09-11 | 2009-04-02 | Hitachi Global Storage Technologies Netherlands Bv | Perpendicular magnetic recording medium |
| TW200919461A (en) * | 2007-09-21 | 2009-05-01 | Sony Corp | Light-assisted magnetic head apparatus, light-assisted magnetic recording apparatus, and light-assisted magnetic recording method |
| TW200921662A (en) * | 2007-10-17 | 2009-05-16 | Sony Corp | Optical pickup and disc drive apparatus |
| TW200923926A (en) * | 2007-07-30 | 2009-06-01 | Showa Denko Kk | Perpendicular magnetic recording medium and process for producing same, and magnetic recording reproducing apparatus |
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| TW200923926A (en) * | 2007-07-30 | 2009-06-01 | Showa Denko Kk | Perpendicular magnetic recording medium and process for producing same, and magnetic recording reproducing apparatus |
| JP2009070444A (en) * | 2007-09-11 | 2009-04-02 | Hitachi Global Storage Technologies Netherlands Bv | Perpendicular magnetic recording medium |
| TW200919461A (en) * | 2007-09-21 | 2009-05-01 | Sony Corp | Light-assisted magnetic head apparatus, light-assisted magnetic recording apparatus, and light-assisted magnetic recording method |
| TW200921662A (en) * | 2007-10-17 | 2009-05-16 | Sony Corp | Optical pickup and disc drive apparatus |
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