JPH05334647A - Thin film magnetic recording medium - Google Patents
Thin film magnetic recording mediumInfo
- Publication number
- JPH05334647A JPH05334647A JP14084892A JP14084892A JPH05334647A JP H05334647 A JPH05334647 A JP H05334647A JP 14084892 A JP14084892 A JP 14084892A JP 14084892 A JP14084892 A JP 14084892A JP H05334647 A JPH05334647 A JP H05334647A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic
- thin film
- magnetic recording
- recording medium
- magnetic field
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000005291 magnetic effect Effects 0.000 title claims abstract description 170
- 239000010409 thin film Substances 0.000 title claims abstract description 66
- 239000000758 substrate Substances 0.000 claims abstract description 7
- 238000010438 heat treatment Methods 0.000 claims description 18
- 239000002885 antiferromagnetic material Substances 0.000 claims description 9
- 239000010408 film Substances 0.000 abstract description 17
- 230000005415 magnetization Effects 0.000 abstract description 10
- 230000005290 antiferromagnetic effect Effects 0.000 abstract description 8
- 239000000314 lubricant Substances 0.000 abstract description 4
- 230000001681 protective effect Effects 0.000 abstract description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 abstract description 3
- 229910052799 carbon Inorganic materials 0.000 abstract description 3
- 238000004544 sputter deposition Methods 0.000 abstract description 3
- 229910002551 Fe-Mn Inorganic materials 0.000 abstract 1
- 229910045601 alloy Inorganic materials 0.000 abstract 1
- 239000000956 alloy Substances 0.000 abstract 1
- 230000001105 regulatory effect Effects 0.000 abstract 1
- 239000000126 substance Substances 0.000 abstract 1
- 230000007547 defect Effects 0.000 description 13
- 238000010586 diagram Methods 0.000 description 13
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 8
- 229910052804 chromium Inorganic materials 0.000 description 8
- 239000011651 chromium Substances 0.000 description 8
- 238000000034 method Methods 0.000 description 7
- 230000006911 nucleation Effects 0.000 description 6
- 238000010899 nucleation Methods 0.000 description 6
- 239000011159 matrix material Substances 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 2
- 229910017052 cobalt Inorganic materials 0.000 description 2
- 239000010941 cobalt Substances 0.000 description 2
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000004907 flux Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 229910052715 tantalum Inorganic materials 0.000 description 2
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 description 2
- 229910000640 Fe alloy Inorganic materials 0.000 description 1
- 241000824268 Kuma Species 0.000 description 1
- 229910000914 Mn alloy Inorganic materials 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- DALUDRGQOYMVLD-UHFFFAOYSA-N iron manganese Chemical compound [Mn].[Fe] DALUDRGQOYMVLD-UHFFFAOYSA-N 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 238000007736 thin film deposition technique Methods 0.000 description 1
Landscapes
- Magnetic Record Carriers (AREA)
- Manufacturing Of Magnetic Record Carriers (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は高密度磁気記録に対応す
る薄膜磁気記録媒体に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film magnetic recording medium compatible with high density magnetic recording.
【０００２】[0002]
【従来の技術】従来、薄膜磁気記録媒体は、基体上に種
々の薄膜堆積法の技術を用いて磁気記録用磁性薄膜を形
成するものであり、コンピュータの外部記憶装置用ハー
ドディスクや磁気テープとして用いられている。しか
し、最近の高密度記録化の急速な進行にともない、ます
ます高性能な薄膜磁気記録媒体が要求されている。従来
の薄膜磁気記録媒体の技術例として、薄膜磁気ディスク
について述べる。図１に示すように、従来技術による薄
膜磁気ディスクは、ニッケル・リンめっきを施したアル
ミニウム基板１の表面にスパッタリング法等により、ク
ロム等の下地膜２を形成し、その上に磁気記録用磁性薄
膜であるコバルト・クロム・タンタル等の磁性薄膜３を
形成し、さらにカーボン等の保護膜４を形成する構造と
なっている。また、場合によっては磁気ヘッドとの摩擦
係数を低減するために潤滑剤５が塗布される。上述のよ
うな構造を有する従来技術の薄膜磁気ディスクは、製造
が容易であるが、磁気記録用磁性薄膜３のＢＨ曲線上の
角型性や保磁力等の磁気特性、及び磁気記録の記録再生
特性等がクロム下地膜によって大きく影響を受けるのが
特徴である。特に、保磁力はクロム下地膜２の影響を強
く受け、その存在有無によって６００Ｏｅから１５００
Ｏｅまで大幅に変化する。クロム下地膜厚が１００Ａ程
度の領域で微妙に保磁力が変化し、安定な保磁力を確保
するためには２００Ａ以上の膜厚が必要であることが知
られている。この原因については、クロム下地膜２と磁
気記録用磁性薄膜３の間の結晶学的な配向性が重要であ
るとされているが、その理由は明かでない。2. Description of the Related Art Conventionally, a thin film magnetic recording medium is one in which a magnetic thin film for magnetic recording is formed on a substrate by using various thin film deposition techniques, and is used as a hard disk or a magnetic tape for an external storage device of a computer. Has been. However, with the recent rapid progress in high-density recording, there has been a demand for an even higher-performance thin film magnetic recording medium. A thin film magnetic disk will be described as a technical example of a conventional thin film magnetic recording medium. As shown in FIG. 1, a thin film magnetic disk according to the prior art has a base film 2 of chromium or the like formed on the surface of an aluminum substrate 1 plated with nickel / phosphorus by a sputtering method or the like, and a magnetic recording magnetic film is formed on the base film 2. A magnetic thin film 3 of cobalt, chromium, tantalum or the like, which is a thin film, is formed, and a protective film 4 of carbon or the like is further formed. In some cases, a lubricant 5 is applied to reduce the coefficient of friction with the magnetic head. The conventional thin-film magnetic disk having the above-mentioned structure is easy to manufacture, but the magnetic characteristics such as the squareness and coercive force on the BH curve of the magnetic recording magnetic thin film 3 and the recording / reproducing of magnetic recording. The characteristic is that the characteristics and the like are greatly affected by the chromium underlayer film. In particular, the coercive force is strongly influenced by the chromium underlayer film 2, and the coercive force varies from 600 Oe to 1500 depending on the presence or absence thereof.
It greatly changes to Oe. It is known that the coercive force subtly changes in a region where the chromium underlayer film thickness is about 100 A, and that a film thickness of 200 A or more is necessary to secure a stable coercive force. Regarding this cause, it is said that the crystallographic orientation between the chromium underlayer film 2 and the magnetic thin film 3 for magnetic recording is important, but the reason is not clear.
【０００３】[0003]
【発明が解決しようとする課題】本発明は、上記従来技
術例の保磁力の原因を究明する過程で導かれたものであ
り、将来の高密度記録の要求に答えた高性能な薄膜磁気
記録媒体を提供することを目的とするものである。The present invention was introduced in the process of investigating the cause of the coercive force of the above-mentioned prior art examples, and is a high-performance thin film magnetic recording that meets the demand for future high-density recording. It is intended to provide a medium.
【０００４】[0004]
【課題を解決するための手段】本発明は、基体上に下地
用磁性薄膜を介して磁気記録用磁性薄膜を形成してなる
薄膜磁気記録媒体において、前記下地用磁性薄膜が反強
磁性体よりなり、かつそのネール温度が５０℃以上であ
ることを特徴としている。SUMMARY OF THE INVENTION The present invention provides a thin film magnetic recording medium comprising a magnetic thin film for magnetic recording formed on a substrate via a magnetic thin film for underlayer, wherein the magnetic thin film for underlayer is made of an antiferromagnetic material. And has a Neel temperature of 50 ° C. or higher.
【０００５】[0005]
【作用】上記構成によれば、特に下地用薄膜と磁気記録
用磁性薄膜との結晶方位の特別な関係を保つ必要もな
く、単に下地用磁性薄膜を反強磁性体にすることにより
高保磁力を確保することができ、高性能な薄膜磁気記録
媒体を実現できる。According to the above construction, it is not necessary to maintain a special crystal orientation relationship between the underlayer thin film and the magnetic recording magnetic thin film, and a high coercive force can be obtained by simply using the underlayer thin film as an antiferromagnetic material. A thin film magnetic recording medium of high performance can be realized.
【０００６】本発明の理論的背景：最近、永久磁石の磁
化反転機構に関する理論的検討結果が発表された（A.Sa
kuma,S.Tanigawa,M.Tokunaga;J.Magn.Magn.Mat. 84 (19
90) 52-58）。図２は前記参考文献から引用した一層欠
陥のモデル図である。一軸異方性定数Ｋmと飽和磁化Ｍm
及び交換定数Ａm等の材料特性を有する永久磁石の母相
６の中に、図２に示すように一軸異方性定数Ｋdと飽和
磁化Ｍd及び交換定数Ａd等の材料特性を有する厚み２Ｄ
の一層の欠陥相７が存在している。母相６及び欠陥相７
とも一軸異方性を有するものとし、その容易軸方向が一
層の面内に平行なｙ軸方向を向いていると仮定して計算
されている。図中矢印は磁気モーメントを示す。図３
は、−ｙ軸方向に外部磁界Ｈextを印加し、母相６の磁
気モーメントが反転する臨界磁界ｈ（以後反転磁界と呼
ぶ）の変化を欠陥相７の異方性定数に対して示した計算
結果である。横軸は規格化された異方性定数ｋであり、Theoretical Background of the Present Invention: Recently, theoretical results regarding the magnetization reversal mechanism of permanent magnets have been announced (A.Sa.
kuma, S.Tanigawa, M.Tokunaga; J.Magn.Magn.Mat. 84 (19
90) 52-58). FIG. 2 is a model diagram of a further defect taken from the above reference. Uniaxial anisotropy constant Km and saturation magnetization Mm
, And a thickness 2D having material properties such as uniaxial anisotropy constant Kd, saturation magnetization Md, and exchange constant Ad in the matrix 6 of the permanent magnet having material properties such as exchange constant Am.
There is one more defect phase 7 of the above. Mother phase 6 and defect phase 7
Both have uniaxial anisotropy, and the easy axis direction is calculated assuming that they are oriented in the y-axis direction parallel to one plane. The arrow in the figure indicates the magnetic moment. Figure 3
Is a calculation showing the change in the critical magnetic field h (hereinafter referred to as the reversal magnetic field) at which the magnetic moment of the mother phase 6 is reversed with respect to the anisotropy constant of the defect phase 7 when the external magnetic field Hext is applied in the -y axis direction. The result. The horizontal axis represents the normalized anisotropy constant k,
【数１】ｋ＝ＡdＫd／ＡmＫm で定義される。縦軸は母相の異方性磁界Ｈk＝２Ｋm／Ｍ
mで規格化した反転磁界ｈであり、## EQU1 ## Defined by k = AdKd / AmKm. The vertical axis represents the anisotropic magnetic field of the matrix Hk = 2 Km / M
The reversal magnetic field h standardized by m,
【数２】ｈ＝Ｈext／（２Ｋm／Ｍm） で定義される。なお、図３の計算結果は欠陥相７の厚み
２Ｄが充分に厚いという前提のものに行われている。前
記理論検討によると、欠陥相７により支配されるニュー
クリエーション機構は、ｍを一定とした場合、欠陥相７
の規格化異方性定数ｋの大きさにより次の三つの領域に
分けられる。但し、ここでｍは規格化された欠陥相７の
飽和磁化であり、## EQU2 ## It is defined by h = Hext / (2Km / Mm). The calculation result of FIG. 3 is performed on the assumption that the thickness 2D of the defect phase 7 is sufficiently thick. According to the theoretical study, the nucleation mechanism dominated by the defect phase 7 has a defect phase 7 when m is constant.
It is divided into the following three regions according to the magnitude of the normalized anisotropy constant k of Where m is the normalized saturation magnetization of the defect phase 7,
【数３】ｍ＝ＡdＭd／ＡmＭm で定義される。（以後ニュークリエーション機構による
反転磁界をニュークリエーション磁界ｈnと呼び、同じ
ようにピニング機構によるものをピニング磁界ｈpと呼
ぶ。） 「領域１」０＜ｋ＜ｋo＝ｍ／（２ｍ＋２√ｍ＋１）の
領域では、欠陥相７が最初に反転し次に母相６が反転す
る。このときはニュークリエーション磁界ｈnとピニン
グ磁界ｈpは同じとなり、次に示す数４式に従う。 「領域２」ｋo＜ｋ＜ｍの領域では、欠陥相７と母相６
は同時に反転する。このときはｈn＝ｋ／ｍの関係があ
る。 「領域３」ｍ＜ｋの領域では、母相６が最初に反転す
る。このときは、ニュークリエーション磁界はｈn＝１
と一定であり、母相６の異方性磁界Ｈkそのものが反転
磁界となる。また、ピニング機構による反転磁界ｈp
（ピニング磁界）は、## EQU3 ## It is defined by m = AdMd / AmMm. (Hereinafter, the reversal magnetic field by the nucleation mechanism is called the nucleation magnetic field hn, and similarly, the one by the pinning mechanism is called the pinning magnetic field hp.) "Region 1" Region of 0 <k <ko = m / (2m + 2√m + 1) Then, the defect phase 7 is inverted first, and then the mother phase 6 is inverted. At this time, the nucleation magnetic field hn and the pinning magnetic field hp become the same, and the following formula 4 is followed. In the region of “region 2” ko <k <m, the defect phase 7 and the mother phase 6
Are reversed at the same time. At this time, there is a relation of hn = k / m. In the region of “region 3” m <k, the mother phase 6 is inverted first. At this time, the nucleation magnetic field is hn = 1
And the anisotropic magnetic field Hk of the mother phase 6 itself becomes the reversal magnetic field. In addition, the reversal magnetic field hp by the pinning mechanism
(Pinning magnetic field) is
【数４】ｈp＝ ｜１−ｋ｜／（ ２ｍ＋２√ｍ＋１） の関係式に従い変化する。次に、図２のモデルを磁気記
録媒体に当てはめ本発明の基本となる考えを述べる。図
２において、欠陥相７の中心で分割した右側半分の領域
を考える。すなわち図４に示すように、欠陥相７の部分
を下地用磁性薄膜８とみなし、母相６を磁気記録用磁性
薄膜３とみなすことができる。このように考えて、図３
において考察すると、母相６の反転磁界であるニューク
リエーション磁界ｈnとピニング磁界ｈpを向上させるた
めには、ｍが小さい方がよいことが容易に理解できる。
図５に代表的な例として、ｍ＝０の場合の反転磁界ｈの
ｋ依存性を示す。ｈn＝１の第３の領域が全てとなり、
ｋが０に近いところでは、ｈpの落込みもそれほど大き
くない。これらのことから、母相６の反転磁界ｈを増加
させるためには、ｍが零で、かつｋは０より大きいある
有限の値を持った方がよいことが分かる。すなわち、交
換定数が同じ（Ａd＝Ａm）と仮定すると、ｍ＝０という
ことは、下地用磁性薄膜８の飽和磁化は零であることを
意味し、これは他ならず反強磁性体であることを意味し
ている。図中矢印は反強磁性体を表すために互いに逆方
向に並ぶように示した。また、図４の構造を磁気記録媒
体として用いる場合、反強磁性体である下地用磁性薄膜
の磁化が反転させられることは好ましくないのでｋ＞０
が必要である。すなわち、交換定数が同じ（Ａd＝Ａm）
と仮定すると、下地用磁性薄膜８の異方性磁界が磁気記
録用磁性薄膜の異方性磁界より大きいことが必要であ
る。ここで、反強磁性体である下地用磁性薄膜８の異方
性磁界は、ｍ＝０のため理論上は無限大である。このこ
とからｋが有限の値を持てば下地用磁性薄膜の磁化は反
転することはない。以上の考えを基本にして以下の実施
例を検討した。## EQU4 ## It changes according to the relational expression of hp = | 1-k | / (2m + 2√m + 1). Next, the basic idea of the present invention will be described by applying the model of FIG. 2 to a magnetic recording medium. In FIG. 2, consider the right half region divided at the center of the defect phase 7. That is, as shown in FIG. 4, the defect phase 7 can be regarded as the underlayer magnetic thin film 8 and the matrix phase 6 can be regarded as the magnetic recording magnetic thin film 3. Thinking this way,
In consideration of the above, it can be easily understood that in order to improve the nucleation magnetic field hn and the pinning magnetic field hp which are the reversal magnetic fields of the mother phase 6, it is preferable that m is smaller.
As a typical example, FIG. 5 shows the k dependence of the reversal magnetic field h when m = 0. The third region with hn = 1 becomes all,
When k is close to 0, the drop of hp is not so large. From these, it is understood that in order to increase the reversal magnetic field h of the mother phase 6, it is preferable that m is zero and k has a certain finite value larger than zero. That is, assuming that the exchange constants are the same (Ad = Am), m = 0 means that the saturation magnetization of the underlying magnetic thin film 8 is zero, which is an antiferromagnetic material. It means that. In the figure, the arrows are shown so as to line up in opposite directions to represent the antiferromagnetic material. When the structure shown in FIG. 4 is used as a magnetic recording medium, it is not preferable that the magnetization of the magnetic thin film for the underlayer, which is an antiferromagnetic material, be reversed, so k> 0.
is necessary. That is, the exchange constant is the same (Ad = Am)
Assuming that, the anisotropic magnetic field of the underlying magnetic thin film 8 needs to be larger than the anisotropic magnetic field of the magnetic recording magnetic thin film. Here, the anisotropic magnetic field of the magnetic thin film 8 for the underlayer, which is an antiferromagnetic material, is theoretically infinite because m = 0. Therefore, if k has a finite value, the magnetization of the underlayer magnetic thin film will not be reversed. The following examples were examined based on the above idea.
【０００７】[0007]
【実施例】以下、図面を参照しつつ本発明の実施例を詳
細に説明する。図６は本発明の薄膜磁気記録媒体の一つ
の実施例を示す薄膜磁気ディスクの要部断面図である図
６に示すように、アルミニウム基板１の表面にスパッタ
リング法等により、鉄・マンガン系合金の反強磁性薄膜
を下地膜８として形成する。その上に磁気記録用磁性薄
膜であるコバルト・クロム・タンタル等の磁性薄膜３を
形成する。さらにカーボン等の保護膜４及び潤滑剤５の
塗布は従来技術と変わらない。前記下地用磁性薄膜８の
飽和磁化は反強磁性体のため零である。上述のような構
造を有する薄膜磁気ディスクの磁気記録用磁性薄膜の保
磁力は約１２００Ｏe程度のものが得られた。この値は
クロムの下地膜２の場合に比較してそれほど大きくない
が、下地膜がない場合に比較して約２倍程度の保磁力の
増加が見られた。図７は本発明のもう一つの実施例であ
る磁界中熱処理の方法を示す図である。熱処理中、磁気
ディスク９の半径方向に磁界が印加されるように永久磁
石１０ａと１０ｂが配されている。永久磁石１０ａは磁
気ディスクの中心を貫通し、矢印方向に磁化されてい
る。また、永久磁石１０ｂは円弧状の形状をしており、
同じように矢印方向に磁化されている。１１は永久磁石
１０ａの裏側の磁束を吸収するためのヨ−クであり、磁
気ディスクが半径方向以外の方向に着磁されることを防
いでいる。永久磁石１０ｂの裏側の磁束も同じように吸
収する必要があるが、図では省略してある。さらに、熱
処理中に磁気ディスク９全体に一様に磁界が印加される
ように、磁気ディスク９は回転している。本実施例の磁
界中熱処理の磁界の方向が、磁気記録のトラックの長手
方向に対して垂直であることは容易に理解できるであろ
う。Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 6 is a cross-sectional view of a main part of a thin film magnetic disk showing one embodiment of the thin film magnetic recording medium of the present invention. As shown in FIG. 6, an iron / manganese alloy is formed on the surface of an aluminum substrate 1 by a sputtering method or the like. The antiferromagnetic thin film is formed as the base film 8. A magnetic thin film 3 of cobalt, chromium, tantalum or the like, which is a magnetic thin film for magnetic recording, is formed thereon. Further, the application of the protective film 4 of carbon or the like and the lubricant 5 is the same as in the prior art. The saturation magnetization of the underlayer magnetic thin film 8 is zero because it is an antiferromagnetic material. The coercive force of the magnetic thin film for magnetic recording of the thin film magnetic disk having the above structure was about 1200 Oe. Although this value is not so large as compared with the case of the underlayer film 2 of chromium, the coercive force is increased about twice as compared with the case without the underlayer film. FIG. 7 is a diagram showing a method of heat treatment in a magnetic field which is another embodiment of the present invention. The permanent magnets 10a and 10b are arranged so that a magnetic field is applied in the radial direction of the magnetic disk 9 during the heat treatment. The permanent magnet 10a penetrates the center of the magnetic disk and is magnetized in the arrow direction. Further, the permanent magnet 10b has an arc shape,
Similarly, it is magnetized in the direction of the arrow. Reference numeral 11 denotes a yoke for absorbing the magnetic flux on the back side of the permanent magnet 10a, which prevents the magnetic disk from being magnetized in a direction other than the radial direction. It is necessary to similarly absorb the magnetic flux on the back side of the permanent magnet 10b, but it is omitted in the figure. Further, the magnetic disk 9 is rotated so that the magnetic field is uniformly applied to the entire magnetic disk 9 during the heat treatment. It can be easily understood that the direction of the magnetic field of the heat treatment in the magnetic field of this example is perpendicular to the longitudinal direction of the track of magnetic recording.
【０００８】図８は本発明の実施例で磁界中熱処理のも
う一つの方法を示す図である。熱処理中、磁気ディスク
９の円周方向に磁界が印加されるように薄板状の永久磁
石１２が磁気ディスク９の一部分の上部に配されてい
る。永久磁石１１は矢印で示すように薄板の厚み方向に
着磁されている。この永久磁石の漏洩磁界により磁気デ
ィスク９は磁気記録のトラックの長手方向と平行方向に
磁化される。熱処理中に磁気ディスク９全体に一様に磁
界が印加されるように、磁気ディスク９は回転してい
る。図９は本発明の実施例である図８に類似した実施例
であり、永久磁石１２を上下２個用いた場合である。永
久磁石１２ａ、１２ｂは同極が同じ側になるように配列
している。これにより磁気ディスク９の上下面を同時に
磁界中熱処理することができる。図１０は本発明の他の
実施例を示し、二つの薄板状の永久磁石１３ａ、１３ｂ
を面内に着磁し、図に示すように配し、磁気ディスク９
の平面に垂直に磁界が印加されるようにした場合であ
る。本実施例の磁界中熱処理の磁界の方向は、磁気記録
のトラックの長手方向に対して垂直であることは容易に
理解できるであろう。図１１は、本発明の磁気記録媒体
の実施例として磁気ディスクにおける磁気記録の記録再
生特性を測定した結果を示す。磁気記録は同一の磁気ヘ
ッドで行われた。図中１４は磁界中熱処理を施さなかっ
た磁気ディスクの場合であり、図中１５は２５０℃の温
度から徐冷して磁界中熱処理を施した磁気ディスクの場
合である。約１０％の再生出力の向上を確認することが
できた。鉄・マンガン系反強磁性体のネール温度は２０
０℃近傍であり、前記温度から徐冷することにより、磁
界中熱処理の効果を有効に引き出すことができる。ま
た、下地用磁性薄膜は、磁気ディスクの使用環境で反強
磁性の特性を維持する必要があり、該反強磁性体のネー
ル温度は室温より高い５０℃以上であることが望まし
い。以上の実施例は、磁気ディスクのみについて示した
が、下地膜として、飽和磁化が零である反強磁性体であ
り、かつそのネール温度が５０℃以上の反強磁性薄膜を
用いることは本発明の請求の範囲の基礎的事項であり、
磁気テープその他の磁気記録媒体に適用可能であること
は、容易に理解できるであろう。FIG. 8 is a diagram showing another method of heat treatment in a magnetic field according to the embodiment of the present invention. A thin plate-shaped permanent magnet 12 is arranged above a part of the magnetic disk 9 so that a magnetic field is applied in the circumferential direction of the magnetic disk 9 during the heat treatment. The permanent magnet 11 is magnetized in the thickness direction of the thin plate as shown by the arrow. The magnetic field leaked from the permanent magnet magnetizes the magnetic disk 9 in the direction parallel to the longitudinal direction of the magnetic recording track. The magnetic disk 9 is rotated so that the magnetic field is uniformly applied to the entire magnetic disk 9 during the heat treatment. FIG. 9 shows an embodiment similar to FIG. 8, which is an embodiment of the present invention, in which two upper and lower permanent magnets 12 are used. The permanent magnets 12a and 12b are arranged so that the same poles are on the same side. As a result, the upper and lower surfaces of the magnetic disk 9 can be simultaneously heat-treated in a magnetic field. FIG. 10 shows another embodiment of the present invention, in which two thin plate-shaped permanent magnets 13a and 13b are provided.
Are magnetized in the plane and arranged as shown in the figure, and the magnetic disk 9
This is the case where the magnetic field is applied perpendicularly to the plane. It can be easily understood that the direction of the magnetic field of the heat treatment in the magnetic field of this example is perpendicular to the longitudinal direction of the track of magnetic recording. FIG. 11 shows the results of measuring the recording / reproducing characteristics of magnetic recording on a magnetic disk as an example of the magnetic recording medium of the present invention. Magnetic recording was performed with the same magnetic head. Reference numeral 14 in the drawing shows the case of the magnetic disk which was not subjected to the heat treatment in the magnetic field, and 15 in the drawing shows the case of the magnetic disk which was subjected to the heat treatment in the magnetic field after being gradually cooled from the temperature of 250 ° C. It was confirmed that the reproduction output was improved by about 10%. The Neel temperature of iron-manganese antiferromagnet is 20
The temperature is around 0 ° C., and the effect of heat treatment in a magnetic field can be effectively brought out by gradually cooling from the above temperature. Further, the magnetic thin film for the underlayer needs to maintain the antiferromagnetic property in the usage environment of the magnetic disk, and the Neel temperature of the antiferromagnetic material is preferably 50 ° C. or higher, which is higher than room temperature. Although the above examples are shown only for the magnetic disk, it is not necessary to use an antiferromagnetic thin film having a saturation magnetization of zero and a Neel temperature of 50 ° C. or higher as the underlayer film according to the present invention. Is the basic matter of the claims of
It can be easily understood that it can be applied to magnetic tapes and other magnetic recording media.
【０００９】[0009]
【発明の効果】本発明によれば、下地膜として５０℃以
上のネール点を有する反強磁性薄膜を用いることによ
り、磁気記録用磁性薄膜の磁気特性を制御できることか
ら従来構造に比較して容易に高性能な磁気記録媒体を提
供し得る。According to the present invention, the use of an antiferromagnetic thin film having a Neel point of 50 ° C. or higher as the underlayer makes it possible to control the magnetic characteristics of the magnetic thin film for magnetic recording, which is easier than the conventional structure. It is possible to provide a high-performance magnetic recording medium.
【図１】従来技術の磁気記録媒体の要部断面図である。FIG. 1 is a cross-sectional view of essential parts of a conventional magnetic recording medium.
【図２】本発明の基本となったモデル図を示す図であ
る。FIG. 2 is a diagram showing a model diagram which is the basis of the present invention.
【図３】本発明の基本となったモデルについてその解析
結果を示す図である。FIG. 3 is a diagram showing an analysis result of a model which is a basis of the present invention.
【図４】本発明の原理構造のモデルを示す図である。FIG. 4 is a diagram showing a model of the principle structure of the present invention.
【図５】本発明の基本となったモデルの解析結果を示す
図である。FIG. 5 is a diagram showing an analysis result of a model which is the basis of the present invention.
【図６】本発明の実施例の要部断面図である。FIG. 6 is a cross-sectional view of essential parts of an embodiment of the present invention.
【図７】本発明の実施例を示す磁界中熱処理の方法を示
す図である。FIG. 7 is a diagram showing a method of heat treatment in a magnetic field showing an example of the present invention.
【図８】本発明の実施例を示す磁界中熱処理の方法を示
す図である。FIG. 8 is a diagram showing a method of heat treatment in a magnetic field showing an example of the present invention.
【図９】本発明の実施例を示す磁界中熱処理の方法を示
す図である。FIG. 9 is a diagram showing a method of heat treatment in a magnetic field showing an example of the present invention.
【図１０】本発明の実施例を示す磁界中熱処理の方法を
示す図である。FIG. 10 is a diagram showing a method of heat treatment in a magnetic field according to an example of the present invention.
【図１１】本発明の効果を示す図である。FIG. 11 is a diagram showing an effect of the present invention.
１ 基体 ２ 下地膜 ３ 磁気記録用磁性薄膜 ４ 保護膜 ５ 潤滑剤 ６ 母相 ７ 欠陥相 ８ 下地用磁性薄膜 ９ 磁気ディスク １０ａ 永久磁石 １０ｂ 永久磁石 １１ ヨ−ク １２ 永久磁石 １２ａ 永久磁石 １２ｂ 永久磁石 １３ａ 永久磁石 １３ｂ 永久磁石 DESCRIPTION OF SYMBOLS 1 Substrate 2 Underlayer film 3 Magnetic thin film for magnetic recording 4 Protective film 5 Lubricant 6 Mother phase 7 Defect phase 8 Underlayer magnetic thin film 9 Magnetic disk 10a Permanent magnet 10b Permanent magnet 11 Yoke 12 Permanent magnet 12a Permanent magnet 12b Permanent magnet 13a permanent magnet 13b permanent magnet
───────────────────────────────────────────────────── フロントページの続き (72)発明者 伊藤 康平 埼玉県熊谷市三ケ尻5200番地日立金属株式 会社磁性材料研究所内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kohei Ito 5200 Mikashiri, Kumagaya, Saitama Hitachi Metals Co., Ltd.
Claims (4)
録用磁性薄膜を形成してなる薄膜磁気記録媒体におい
て、該下地用磁性薄膜は反強磁性体であり、かつそのネ
ール温度が５０℃以上であることを特徴とする薄膜磁気
記録媒体。1. A thin-film magnetic recording medium in which a magnetic thin film for magnetic recording is formed on a substrate through a magnetic thin film for underlayer, wherein the magnetic thin film for underlayer is an antiferromagnetic material, and its Neel temperature is 50. A thin film magnetic recording medium characterized by having a temperature of ℃ or higher.
上に前記磁気記録磁性薄膜を形成した後に磁界中熱処理
を行うことを特徴とする薄膜磁気記録媒体。2. The thin film magnetic recording medium according to claim 1, wherein after the magnetic recording magnetic thin film is formed on the underlying magnetic thin film, heat treatment is performed in a magnetic field.
の磁界の方向が前記薄膜磁気記録媒体の磁気記録のトラ
ック方向に対して垂直であることを特徴とする薄膜磁気
記録媒体。3. The thin film magnetic recording medium according to claim 1, wherein the direction of the magnetic field of the heat treatment in the magnetic field is perpendicular to the track direction of magnetic recording of the thin film magnetic recording medium.
の磁界の方向が前記薄膜磁気記録媒体の磁気記録のトラ
ック方向に対して平行であることを特徴とする薄膜磁気
記録媒体。4. The thin film magnetic recording medium according to claim 2, wherein the direction of the magnetic field of the heat treatment in a magnetic field is parallel to the track direction of magnetic recording of the thin film magnetic recording medium.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14084892A JPH05334647A (en) | 1992-06-02 | 1992-06-02 | Thin film magnetic recording medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14084892A JPH05334647A (en) | 1992-06-02 | 1992-06-02 | Thin film magnetic recording medium |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH05334647A true JPH05334647A (en) | 1993-12-17 |
Family
ID=15278139
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14084892A Pending JPH05334647A (en) | 1992-06-02 | 1992-06-02 | Thin film magnetic recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH05334647A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004077413A1 (en) * | 2003-02-19 | 2004-09-10 | Neomax Co., Ltd. | In-magnetic-field heat-treating device |
-
1992
- 1992-06-02 JP JP14084892A patent/JPH05334647A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004077413A1 (en) * | 2003-02-19 | 2004-09-10 | Neomax Co., Ltd. | In-magnetic-field heat-treating device |
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