JPH0254645B2 - - Google Patents
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- Publication number
- JPH0254645B2 JPH0254645B2 JP2735884A JP2735884A JPH0254645B2 JP H0254645 B2 JPH0254645 B2 JP H0254645B2 JP 2735884 A JP2735884 A JP 2735884A JP 2735884 A JP2735884 A JP 2735884A JP H0254645 B2 JPH0254645 B2 JP H0254645B2
- Authority
- JP
- Japan
- Prior art keywords
- film
- heat treatment
- iron oxide
- perpendicularly
- film surface
- 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.)
- Expired
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- 239000010408 film Substances 0.000 claims description 79
- 230000005415 magnetization Effects 0.000 claims description 22
- 239000010409 thin film Substances 0.000 claims description 20
- 229910001566 austenite Inorganic materials 0.000 claims description 19
- 238000010438 heat treatment Methods 0.000 claims description 19
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical group [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 claims description 16
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 12
- 229910052762 osmium Inorganic materials 0.000 claims description 8
- 238000004519 manufacturing process Methods 0.000 claims description 7
- 239000001257 hydrogen Substances 0.000 claims description 4
- 229910052739 hydrogen Inorganic materials 0.000 claims description 4
- 238000000034 method Methods 0.000 claims description 4
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 3
- SZVJSHCCFOBDDC-UHFFFAOYSA-N iron(II,III) oxide Inorganic materials O=[Fe]O[Fe]O[Fe]=O SZVJSHCCFOBDDC-UHFFFAOYSA-N 0.000 claims description 3
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 claims description 3
- SYQBFIAQOQZEGI-UHFFFAOYSA-N osmium atom Chemical compound [Os] SYQBFIAQOQZEGI-UHFFFAOYSA-N 0.000 claims description 3
- 229910052595 hematite Inorganic materials 0.000 claims description 2
- 239000011019 hematite Substances 0.000 claims description 2
- LIKBJVNGSGBSGK-UHFFFAOYSA-N iron(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Fe+3].[Fe+3] LIKBJVNGSGBSGK-UHFFFAOYSA-N 0.000 claims description 2
- 239000006185 dispersion Substances 0.000 claims 1
- 239000011651 chromium Substances 0.000 description 12
- 229910000859 α-Fe Inorganic materials 0.000 description 9
- 238000004544 sputter deposition Methods 0.000 description 6
- 239000000758 substrate Substances 0.000 description 5
- 229910045601 alloy Inorganic materials 0.000 description 4
- 239000000956 alloy Substances 0.000 description 4
- 238000005260 corrosion Methods 0.000 description 4
- 230000007797 corrosion Effects 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- 239000002184 metal Substances 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000012528 membrane Substances 0.000 description 2
- 239000008188 pellet Substances 0.000 description 2
- 229910000929 Ru alloy Inorganic materials 0.000 description 1
- WAIPAZQMEIHHTJ-UHFFFAOYSA-N [Cr].[Co] Chemical class [Cr].[Co] WAIPAZQMEIHHTJ-UHFFFAOYSA-N 0.000 description 1
- 229910002065 alloy metal Inorganic materials 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- VLWBWEUXNYUQKJ-UHFFFAOYSA-N cobalt ruthenium Chemical compound [Co].[Ru] VLWBWEUXNYUQKJ-UHFFFAOYSA-N 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000000399 optical microscopy Methods 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 238000005546 reactive sputtering Methods 0.000 description 1
- 231100000241 scar Toxicity 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 238000011282 treatment Methods 0.000 description 1
Landscapes
- Manufacturing Of Magnetic Record Carriers (AREA)
- Thin Magnetic Films (AREA)
- Compounds Of Iron (AREA)
- Magnetic Record Carriers (AREA)
Description
＜技術分野＞
本発明は高記録密度磁気記録装置、特に磁気デ
イスクの磁性媒体として用いられる、膜面に垂直
に磁気異方性を付与した酸化鉄薄膜の製造方法に
関するものである。
＜技術的背景と問題点＞
膜面に垂直に磁気異方性を付与した磁性媒体を
用い、膜面に垂直に磁化することで情報を記録す
るいわゆる垂直磁化記録方式は、記録密度が高く
なる程記録磁化方向にビツト形状が伸びた形にな
るため反磁界が減少し、記録磁化は安定化する。
このため、従来用いられてきた膜面に沿つて平行
に磁気異方性を付与した面内磁化膜に比べ、高い
記録密度が達成できることが判明している。この
資料としては、（S.Iwasakietl：LEEE Trans
Magn.、MAG‐13（1977）1272）がある。
かかる垂直磁化記録方式に用いられる磁性媒体
としては、従来コバルト・クロム合金やコバル
ト・ルテニウム合金等コバルト（Co）基合金金
属膜が使われている。この資料としては、（Ｓ・
Iwasaki etal；IEEE Trans Magn.、MAG‐14
（1978）849、S.Hirono etal；Jpn.J.Apol.
PHys.20（1981）L571）がある。
このCo基合金薄膜は、面に垂直にＣ軸がそろ
つた組識となつている。また、Coの結晶磁気異
方性は一軸性であり、磁化容易軸はＣ軸なので、
結局Co基合金薄膜は膜面に垂直に磁気異方性が
付与される、いわゆる垂直異方性化膜である。因
に、膜面に垂直に測定した場合の残留磁化の方が
膜面に平行に測定した場合の残留磁化より大きい
場合の垂直異方性磁化膜は特に垂直磁化膜とよば
れる。
このような垂直異方性磁化膜であるCo基合金
薄膜の欠点としては、この膜が金属膜であるため
に腐食しやすいものであり、しかも表面硬度が足
りないことである。
＜発明の目的＞
本発明は、上述のCo基合金薄膜の欠点を除き、
耐食性が高く又表面硬度の優れた酸化鉄薄膜につ
き、誘導磁気異方性を膜面に垂直に付与した垂直
異方性磁化膜の製造方法の提供を目的とする。
＜発明の構成＞
かかる目的を達成する本発明は、オスミウム
（Os）を添加した酸化鉄を主成分とする薄膜の膜
面に垂直に磁場を加えながら熱処理を施すことを
特徴とする。
＜実施例＞
実施例 １
直径20cmの鉄（Fe）ターゲツト上にオスミウ
ム（Os）およびCoペレツトを配置し、アルゴン
（Ar）と酸素（O2）が１：１の混合ガス雰囲気中
で応応スパツタリングを行ないヘマタイト（α‐
Fe5O3）薄膜を基板上に形成する。スパツタリン
グ方式は高周波二極スパツタ方式でありスパツタ
リング電力は300W、スパツタ雰囲気圧力は２×
10-2Torrである。基板はガラス基板を用いてい
る。膜中へのOs及びCo添加量はターゲツト上の
ペレツトの量を増減することで制御可能である。
膜厚0.1μｍのα‐Fe2O3膜中にOsおよびCoが金属
元素のみの比率で各々2.3及び3.6at％添加した。
ついで、このａ‐Fe2O3薄膜について以下の３種
類の熱処理を施す。
(1) 加湿した水素（H2）気流中で250℃に１時間
加熱し、マグネタイトFe3O4膜を得る。この
際、膜面に垂直に外部磁場10KOeを加える。
(2) 加湿したH2気流中で250℃に１時間加熱して
Fe3O4膜を得た後、大気中で310℃に４時間加
熱してマグヘマイト（γ‐Fe2O3）膜を得る。
大気中で加熱する際に、膜面に垂直に外部磁場
10KOeを加える。
(3) 加湿したH2気流中で250℃に１時間加熱して
Fe3O4膜を得た後、大気中で310℃に４時間加
熱してγ‐Fe2O3膜を形成した。このγ‐
Fe2O3膜面に垂直に10KOeの外部磁場を加えな
がら、大気中で380℃に１時間加熱する。この
処理ではγ‐Fe2O3の状態が保たれる。
以上に述べた３種類の熱処理を施した後、膜面
に平行方向と垂直方向にヒステリシスループを測
定した。各熱処理後の保磁力（Hc）および残留
磁化（Mr）の値を表‐１に示す。
<Technical Field> The present invention relates to a method for producing an iron oxide thin film having magnetic anisotropy perpendicular to the film surface, which is used as a magnetic medium for high-density magnetic recording devices, particularly magnetic disks. <Technical background and issues> The so-called perpendicular magnetization recording method, which records information by magnetizing perpendicular to the film surface using a magnetic medium with magnetic anisotropy perpendicular to the film surface, has a high recording density. As the bit shape becomes longer in the recording magnetization direction, the demagnetizing field decreases and the recording magnetization becomes more stable.
Therefore, it has been found that a higher recording density can be achieved compared to the conventionally used in-plane magnetized film in which magnetic anisotropy is imparted parallel to the film surface. This material includes (S.Iwasakietl: LEEE Trans
Magn., MAG-13 (1977) 1272). Conventionally, a cobalt (Co)-based alloy metal film such as a cobalt-chromium alloy or a cobalt-ruthenium alloy has been used as a magnetic medium used in such a perpendicular magnetization recording method. This material includes (S.
Iwasaki et al; IEEE Trans Magn., MAG‐14
(1978) 849, S. Hirono etal; Jpn. J. Apol.
PHys.20 (1981) L571). This Co-based alloy thin film has a structure in which the C-axis is aligned perpendicular to the surface. In addition, the magnetocrystalline anisotropy of Co is uniaxial, and the easy axis of magnetization is the C axis.
After all, the Co-based alloy thin film is a so-called perpendicularly anisotropic film in which magnetic anisotropy is imparted perpendicularly to the film surface. Incidentally, a perpendicularly anisotropic magnetized film in which the residual magnetization when measured perpendicular to the film surface is larger than the residual magnetization when measured parallel to the film surface is particularly called a perpendicularly magnetized film. The drawbacks of such a Co-based alloy thin film, which is a perpendicularly anisotropic magnetization film, are that since this film is a metal film, it is easily corroded, and furthermore, the surface hardness is insufficient. <Object of the invention> The present invention eliminates the drawbacks of the above-mentioned Co-based alloy thin film, and
The object of the present invention is to provide a method for manufacturing a perpendicularly anisotropic magnetized film in which induced magnetic anisotropy is imparted perpendicularly to the film surface using an iron oxide thin film having high corrosion resistance and excellent surface hardness. <Structure of the Invention> The present invention, which achieves the above object, is characterized by performing heat treatment while applying a magnetic field perpendicularly to the film surface of a thin film whose main component is iron oxide doped with osmium (Os). <Example> Example 1 Osmium (Os) and Co pellets were placed on an iron (Fe) target with a diameter of 20 cm, and reactive sputtering was performed in a mixed gas atmosphere of 1:1 argon (Ar) and oxygen (O 2 ). Hematite (α-
Fe 5 O 3 ) thin film is formed on the substrate. The sputtering method is a high frequency two-pole sputtering method, the sputtering power is 300W, and the sputtering atmosphere pressure is 2×
10 -2 Torr. A glass substrate is used as the substrate. The amounts of Os and Co added to the film can be controlled by increasing or decreasing the amount of pellets on the target.
Os and Co were added to the α-Fe 2 O 3 film with a thickness of 0.1 μm at a ratio of only metal elements of 2.3 and 3.6 at%, respectively.
Next, this a-Fe 2 O 3 thin film is subjected to the following three types of heat treatment. (1) Heating at 250°C for 1 hour in a humidified hydrogen (H 2 ) stream to obtain a magnetite Fe 3 O 4 film. At this time, an external magnetic field of 10 KOe is applied perpendicular to the film surface. (2) Heated at 250℃ for 1 hour in a humidified H2 stream.
After obtaining the Fe 3 O 4 film, it is heated at 310° C. for 4 hours in the atmosphere to obtain a maghemite (γ-Fe 2 O 3 ) film.
When heating in the atmosphere, an external magnetic field is applied perpendicular to the film surface.
Add 10KOe. (3) Heated at 250℃ for 1 hour in a humidified H2 stream.
After obtaining the Fe 3 O 4 film, it was heated at 310° C. for 4 hours in the air to form a γ-Fe 2 O 3 film. This γ-
While applying an external magnetic field of 10 KOe perpendicular to the Fe 2 O 3 film surface, the film is heated to 380°C for 1 hour in the air. This treatment maintains the γ-Fe 2 O 3 state. After performing the three types of heat treatments described above, hysteresis loops were measured in directions parallel and perpendicular to the film surface. Table 1 shows the coercive force (Hc) and residual magnetization (Mr) values after each heat treatment.
【表】
この表‐１から判明するように全ての試料にお
いて膜面に垂直方向の保磁力（Hc⊥）の方が膜
面に平行な保磁力（Hc）よりも大きくなつて
おり、垂直異方性磁化膜となつていることを示し
ている。特に、熱処理(3)を施した場合には、膜面
の垂直方向の残留磁化（Mr⊥）も膜面に平行方
向の残留磁化（Mr）より大きくなつており、
膜面に平行方向よりも垂直方向に磁化された方が
安定な、いわゆる垂直磁化膜であることを示して
いる。
実施例 ２
実施例１と同様の作製条件でOsのみを金属元
素のみの比率で5.0at％添加したα‐Fe2O3膜を作
製した。膜厚は0.1μｍである。このα−Fe2O3膜
を加湿した水素気流中で250℃に１時間加熱し、
Fe3O4とした後、大気中で310℃に４時間加熱し
てγ−Fe2O3とする。このOs添加γ−Fe2O3膜に
ついて再度、大気中で250℃から680℃の範囲で15
分間加熱する。なお、この際膜面に垂直に
10KOeの外部磁場を印加する。
第１図には保磁力（Hc）及び残留磁化（Mr）
の磁場中熱処理温度依存性を示す。磁場中熱処理
温度が350℃以上の場合には膜面に垂直に測定し
たHcやMrの方が膜面に平行に測定したHcやMr
よりも大きく、垂直磁化膜が形成されている。
実施例 ３
実施例２と同一条件でOsを０〜9.5at％含む
0.2μｍ厚さのα‐Fe2O3薄膜を形成した。この薄
膜を加湿水素気流中で250〜320℃に１時間加熱し
た後、大気中で310℃に４時間加熱しγ−Fe2O3
を主成分とする薄膜を得た。Ｘ線回拆によると
Osを9.5at％添加した膜にはγ−Fe2O3相以外に
微量のα−Fe2O3相が混在していることが確認さ
れている。このOs添加γ−Fe2O3薄膜を膜面に垂
直に10KOeの外部磁場を加えながら大気中で400
℃に15分間加熱した。この磁場中熱処理後のγ−
Fe2O3膜の保磁力（Hc）と残留磁化（Mr）の添
加量依存性を第２図に示す。Hc⊥とMr⊥は膜面
に垂直に測定した保磁力と残留磁化を、Hcと
Mrは膜面に平行に測定した保磁力と残留磁化
を各々示す。Os添加量が0.37〜9.5at％の範囲で
Hc⊥＞Hcが成立し、垂直磁気異方性膜が得ら
れている。特にOs添加量が3.5〜9.5at％の範囲で
は、Mr⊥＞Mrが成立し、垂直磁化膜が得られ
ている。なお、磁場中熱処理時の外部磁場が
4KOeの時も、同様の効果が得られた。
実施例 ４
表面を熱酸化した直径50mmのシリコン（Sf）円
板を基板として用い、他の条件は実施例２と同様
にしてOsを６％添加した0.2μｍ厚のγ−Fe2O3薄
膜を形成した。このγ−Fe2O3薄膜面に垂直に外
部磁場7KOeを加えながら大気中で400℃に30分
間加熱し、垂直磁化膜とした。この垂直磁化膜の
磁気特性は以下の通りである。Hc⊥＝1400Oe、
Hc＝500Oe、Mr⊥＝100Gauss、Mr＝
30Gauss。
このOs添加γ−Fe2O3垂直磁化膜面に直径2.29
mmのMn‐Znフエライト球を押しつけ、相対速度
が１ｍ／secとなるようにデイスクを回転させ、
1000回通過後の媒体面の傷の深さを測定した。
又、スパツタリング法で表面を熱酸化したSi基板
上に81.3at％Co‐18.7at％Cr垂直磁化膜を作製
し、同様の摩耗試験を行つた。Co‐Cr膜の作製
条件は以下の通りである。ターゲツトは直径100
mmの81.3at％Co‐18.7at％Cr円板、スパツタ雰囲
気は２×10-2TorrのArガスであり、高周波電力
200Wを加えて0.2μｍ厚のCo‐Cr膜を得た。この
Co‐Cr膜の磁気特性はHc⊥＝1700Oe、Hc＝
900Oe、Mr⊥＝90Gauss、Mr＝48Gaussであ
る。第３図には、フエライト球の荷重と摩耗傷の
深さの関係を示す。Os添加γ−Fe2O3膜Ａの摩耗
深さはCo‐Cr膜Ｂの約1/5と少ないことがわか
る。
次に、上記のγ−Fe2O3膜とCo‐Cr膜につい
てウインチエスター形のMn‐Znフエライトヘツ
ドを用い、記録再生特性を評価した。ヘツドのコ
ア幅は70μｍ、コイル巻数は20回、ギヤツプ長さ
は0.3μｍであり、周速５ｍ／secで測定した。こ
の時のヘツド浮上量は0.05μｍである。孤立波再
生出力の1/2の出力が得られる記録密度（D50）
はγ−Fe2O3膜が3200FRPM（FluxReversals
per Millmenter）、Co‐Cr膜が3170FRPMであ
つた。即ち、本発明によるγ−Fe2O3垂直磁化膜
は、従来用いられてきたCo‐Cr垂直磁化膜とほ
ぼ同等の記録密度が得られることが確認された。
最後に、上記のOs添加γ−Fe2O3薄膜とCo‐
Cr薄膜を、湿度90％、温度80℃の雰囲気中に100
日間放置し、耐候性を調べた。Os添加γ−Fe2O3
薄膜では腐食等の兆候は目視によつても光学顕微
鏡観察によつても認められなかつたが、Co‐Cr
膜では１cm2当り２〜３箇所の腐食が認められた。
＜発明の効果＞
以上説明したように、本発明によつて作製され
たOs添加酸化鉄の重直異方性磁化膜は、垂直磁
気記録に適した磁気特性を有すると同時に、従来
用いられてきたCo‐Cr膜等の金属薄膜と比べ、
耐摩耗特性や耐食性に優れる等、実用に供する場
合の信頼性を著しく向上させる利点がある。[Table] As is clear from Table 1, in all samples, the coercive force in the direction perpendicular to the film surface (Hc⊥) is larger than the coercive force parallel to the film surface (Hc), and the perpendicular difference This shows that it is a directional magnetization film. In particular, when heat treatment (3) is applied, the residual magnetization in the direction perpendicular to the film surface (Mr⊥) is also larger than the residual magnetization in the direction parallel to the film surface (Mr).
This shows that the film is a so-called perpendicular magnetization film, which is more stable when magnetized perpendicularly to the film surface than in a direction parallel to the film surface. Example 2 An α-Fe 2 O 3 film was produced under the same production conditions as in Example 1, in which only Os was added at a ratio of 5.0 at% to the metal element. The film thickness is 0.1 μm. This α-Fe 2 O 3 film was heated to 250°C for 1 hour in a humidified hydrogen stream.
After converting it into Fe 3 O 4 , it is heated to 310° C. for 4 hours in the air to convert it into γ-Fe 2 O 3 . This Os-added γ-Fe 2 O 3 film was tested again in the air at a temperature of 250°C to 680°C for 15
Heat for a minute. In addition, at this time, perpendicular to the membrane surface
Apply an external magnetic field of 10 KOe. Figure 1 shows coercive force (Hc) and residual magnetization (Mr).
The temperature dependence of heat treatment in a magnetic field is shown. When the heat treatment temperature in a magnetic field is 350℃ or higher, Hc and Mr measured perpendicular to the film surface are higher than Hc and Mr measured parallel to the film surface.
A perpendicularly magnetized film is formed. Example 3 Contains 0 to 9.5 at% Os under the same conditions as Example 2
An α-Fe 2 O 3 thin film with a thickness of 0.2 μm was formed. This thin film was heated to 250 to 320°C for 1 hour in a humidified hydrogen stream, and then heated to 310°C for 4 hours in the air to produce γ-Fe 2 O 3 .
A thin film containing as the main component was obtained. According to the X-ray circuit
It has been confirmed that a film containing 9.5 at% Os contains a small amount of α-Fe 2 O 3 phase in addition to the γ-Fe 2 O 3 phase. This Os-doped γ-Fe 2 O 3 thin film was heated in the atmosphere for 400 min while applying an external magnetic field of 10 KOe perpendicular to the film surface.
℃ for 15 minutes. γ− after this heat treatment in the magnetic field
Figure 2 shows the dependence of the coercive force (Hc) and residual magnetization (Mr) of the Fe 2 O 3 film on the amount of addition. Hc⊥ and Mr⊥ are the coercive force and residual magnetization measured perpendicular to the film surface.
Mr indicates the coercive force and residual magnetization measured parallel to the film surface, respectively. Os addition amount ranges from 0.37 to 9.5at%
Hc⊥>Hc holds, and a perpendicular magnetic anisotropy film is obtained. In particular, when the amount of Os added is in the range of 3.5 to 9.5 at%, Mr⊥>Mr holds true, and a perpendicularly magnetized film is obtained. Note that the external magnetic field during heat treatment in a magnetic field
A similar effect was obtained with 4KOe. Example 4 A silicon (Sf) disk with a diameter of 50 mm with a thermally oxidized surface was used as a substrate, and the other conditions were the same as in Example 2. A 0.2 μm thick γ-Fe 2 O 3 thin film with 6% Os added was formed. was formed. This γ-Fe 2 O 3 thin film was heated to 400° C. for 30 minutes in the air while applying an external magnetic field of 7 KOe perpendicularly to the surface to form a perpendicularly magnetized film. The magnetic properties of this perpendicularly magnetized film are as follows. Hc⊥＝1400Oe,
Hc=500Oe, Mr⊥=100Gauss, Mr=
30 Gauss. This Os-added γ−Fe 2 O 3 perpendicularly magnetized film has a diameter of 2.29 mm.
A Mn-Zn ferrite sphere of mm is pressed against it, and the disk is rotated so that the relative velocity is 1 m/sec.
The depth of scratches on the media surface after passing 1000 times was measured.
In addition, an 81.3at%Co-18.7at%Cr perpendicularly magnetized film was fabricated on a Si substrate whose surface was thermally oxidized by sputtering, and a similar wear test was conducted. The conditions for producing the Co-Cr film are as follows. Target is 100 in diameter
mm 81.3at%Co-18.7at%Cr disk, sputtering atmosphere is Ar gas of 2 × 10 -2 Torr, high frequency power
A 0.2 μm thick Co-Cr film was obtained by applying 200 W. this
The magnetic properties of the Co-Cr film are Hc⊥=1700Oe, Hc=
900Oe, Mr⊥=90Gauss, Mr=48Gauss. FIG. 3 shows the relationship between the load on the ferrite ball and the depth of the wear scar. It can be seen that the wear depth of the Os-added γ-Fe 2 O 3 film A is approximately 1/5 that of the Co-Cr film B. Next, the recording and reproducing characteristics of the above γ-Fe 2 O 3 film and Co-Cr film were evaluated using a winchiester type Mn-Zn ferrite head. The core width of the head was 70 μm, the number of coil turns was 20, the gap length was 0.3 μm, and the measurement was performed at a circumferential speed of 5 m/sec. The flying height of the head at this time is 0.05 μm. Recording density (D 50 ) that provides 1/2 of the solitary wave playback output
The γ-Fe 2 O 3 film is 3200FRPM (FluxReversals
per Millmenter), and the Co-Cr film was 3170 FRPM. In other words, it was confirmed that the γ-Fe 2 O 3 perpendicularly magnetized film according to the present invention can provide almost the same recording density as the conventionally used Co-Cr perpendicularly magnetized film. Finally, the above Os-doped γ-Fe 2 O 3 thin film and Co-
A Cr thin film was placed in an atmosphere with a humidity of 90% and a temperature of 80°C.
It was left to stand for several days and its weather resistance was examined. Os added γ−Fe 2 O 3
No signs of corrosion were observed in the thin film either visually or by optical microscopy, but Co-Cr
Corrosion was observed at 2 to 3 locations per cm 2 of the membrane. <Effects of the Invention> As explained above, the orthotropically magnetized film of Os-doped iron oxide produced by the present invention has magnetic properties suitable for perpendicular magnetic recording, and at the same time has magnetic properties that are better than those conventionally used. Compared to metal thin films such as Co-Cr films,
It has advantages such as excellent wear resistance and corrosion resistance, which significantly improves reliability in practical use.
第１図は磁場中熱処理温度と保磁力（Hc）及
び残留磁化（Mr）の関係を示すグラフ、第２図
はOs添加量と磁場中熱処理後の保磁力（Hc）及
び残留磁化（Mr）の関係を示すグラフ、第３図
はフエライト球圧子荷重と摩耗キズ深さの関係を
示すグラフである。
図中、Mr⊥は膜面垂直方向残留磁化、Mrは
膜面平行方向残留磁化、Hc⊥は膜面垂直方向保
磁力、Hcは膜面平行方向保磁力である。
Figure 1 is a graph showing the relationship between magnetic field heat treatment temperature, coercive force (Hc) and residual magnetization (Mr), and Figure 2 is a graph showing the relationship between Os addition amount and coercive force (Hc) and residual magnetization (Mr) after magnetic field heat treatment. FIG. 3 is a graph showing the relationship between ferrite ball indenter load and wear scratch depth. In the figure, Mr⊥ is the residual magnetization in the direction perpendicular to the film surface, Mr is the residual magnetization in the direction parallel to the film surface, Hc⊥ is the coercive force in the direction perpendicular to the film surface, and Hc is the coercive force in the direction parallel to the film surface.
Claims (1)
する薄膜の膜面に垂直に磁場を加えながら熱処理
を施すことを特徴とする垂直異方性磁化膜の製造
方法。 ２ 上記酸化鉄をヘマタイトａ‐Fe2O3とし、水
素気流中で加熱する上記熱処理を行なうことによ
りマグネタイトFe3O4を形成することを特徴とす
る特許請求の範囲第１項記載の垂直異方性磁化膜
の製造方法。 ３ 上記酸化鉄をマグネタイトFe3O4とし、大気
中で加熱する上記熱処理を行なうことによりマグ
ヘマイトγ‐Fe2O3を形成することを特徴とする
特許請求の範囲第１項記載の垂直異方性磁化膜の
製造方法。 ４ 上記酸化鉄をマグヘマイトγ‐Fe2O3とし、
大気中で加熱する上記熱処理を行なうことを特徴
とする特許請求の範囲第１項記載の垂直異方性磁
化膜の製造方法。[Claims] 1. A method for producing a perpendicularly anisotropic magnetized film, which comprises performing heat treatment while applying a magnetic field perpendicular to the film surface of a thin film whose main component is iron oxide doped with osmium Os. 2. The vertical dispersion according to claim 1, wherein the iron oxide is made into hematite a-Fe 2 O 3 and magnetite Fe 3 O 4 is formed by performing the above heat treatment of heating in a hydrogen stream. Method for manufacturing a directional magnetization film. 3. The perpendicular anisotropy according to claim 1, wherein the iron oxide is made into magnetite Fe 3 O 4 and maghemite γ-Fe 2 O 3 is formed by performing the above heat treatment of heating in the atmosphere. A method for producing a magnetically magnetized film. 4 The above iron oxide is maghemite γ-Fe 2 O 3 ,
2. The method of manufacturing a perpendicularly anisotropic magnetized film according to claim 1, wherein the heat treatment is performed in the atmosphere.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2735884A JPS60173820A (en) | 1984-02-17 | 1984-02-17 | Manufacture of vertical anisotropic magnetized film |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2735884A JPS60173820A (en) | 1984-02-17 | 1984-02-17 | Manufacture of vertical anisotropic magnetized film |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60173820A JPS60173820A (en) | 1985-09-07 |
| JPH0254645B2 true JPH0254645B2 (en) | 1990-11-22 |
Family
ID=12218823
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2735884A Granted JPS60173820A (en) | 1984-02-17 | 1984-02-17 | Manufacture of vertical anisotropic magnetized film |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60173820A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TW569195B (en) | 2001-01-24 | 2004-01-01 | Matsushita Electric Ind Co Ltd | Micro-particle arranged body, its manufacturing method, and device using the same |
-
1984
- 1984-02-17 JP JP2735884A patent/JPS60173820A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60173820A (en) | 1985-09-07 |
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