Method of making a magnetic oxide film with high coercive force
First Claim
1. A method of making a high coercive force magnetic oxide film comprising the steps of sputtering a target made of iron and aluminum in an atmosphere containing an inert gas and oxygen with the oxygen above a certain partial pressure to form on a substrate an α
- -Fe2 O3 non magnetic oxide film having aluminum dissolved therein, and reducing said non-magnetic oxide film under a hydrogen gas atmosphere to yield an Fe3 O4 magnetic oxide film having aluminum dissolved therein.
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Abstract
A magnetic oxide film manufacturing method is disclosed which involves the steps of sputtering a target made of iron and aluminum to form a film of non-magnetic iron oxide (α-Fe2 O3) and reducing the film to obtain a magnetic oxide film. When a target made of iron and aluminum is employed, it is possible to obtain a high coercive force magnetic oxide film which is highly adhesive to a substrate, excellent in surface roughness and less than 0.3μm in thickness. Accordingly, it is possible to obtain a magnetic disk of high magnetic recording density.
17 Citations
7 Claims
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1. A method of making a high coercive force magnetic oxide film comprising the steps of sputtering a target made of iron and aluminum in an atmosphere containing an inert gas and oxygen with the oxygen above a certain partial pressure to form on a substrate an α
- -Fe2 O3 non magnetic oxide film having aluminum dissolved therein, and reducing said non-magnetic oxide film under a hydrogen gas atmosphere to yield an Fe3 O4 magnetic oxide film having aluminum dissolved therein.
- View Dependent Claims (2, 3, 4, 5)
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6. A method of making a high coercive force magnetic oxide film comprising the steps of sputtering a target in a mixed atmosphere of argon and oxygen held at a partial pressure 3 ×
- 10-3 to form an α
-Fe2 O3 non-magnetic oxide film having aluminum dissolved therein, said target being formed from an iron plate and having mounted thereon small aluminum pieces with a surface area ratio of 2 to 4% relative to said iron plate, and reducing said non-magnetic oxide under a hydrogen atmosphere at 280°
to 320°
C to form magnetic oxide having aluminum dissolved therein.
- 10-3 to form an α
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7. A method of making a high coercive force magnetic film comprising the steps of sputtering a target in a mixed atmosphere of argon and oxygen held at a partial pressure above 3 ×
- 10-3 Torr to form on a substrate an α
-Fe2 O3 non-magnetic oxide film having aluminum dissolved therein, said target being made of an ironaluminum alloy composed of 1 to 2% of aluminum and the remainder iron, and reducing said non-magnetic oxide film under a hydrogen atmosphere at 280°
to 320°
C to form a magnetic oxide film having aluminum dissolved therein.
- 10-3 Torr to form on a substrate an α
Specification
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- Resources
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Current AssigneeNippon Telegraph and Telephone Corporation
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Original AssigneeNippon Telegraph and Telephone East Corporation (Nippon Telegraph and Telephone Corporation)
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InventorsIshii, Yoshikazu, Inagaki, Nobuo, Hattori, Seizi
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Primary Examiner(s)Mack, John H.
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Assistant Examiner(s)Weisstuch, Aaron
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Application NumberUS05/604,774Time in Patent Office523 DaysField of Search204/192, 427/130US Class Current204/192.2CPC Class CodesC23C 14/085 of iron group metalsC23C 14/5806 Thermal treatmentC23C 14/5846 Reactive treatmentH01F 10/20 FerritesH01F 41/14 for applying magnetic films...
