Claims
- 1. A perpendicular magnetic recording medium formed on a base and comprising an hcp cobalt alloy layer having opposed major surfaces and comprising mainly cobalt and additionally chromium, said layer having a direction of easy magnetization in a direction normal to the base, characterized in that the cobalt alloy layer is composed of particles, with a boundary between the particles forming a non-columnar pattern extending between said surfaces of said cobalt alloy layer, as seen in a cross section of the layer observed with a scanning electron microscope, thereby providing said cobalt alloy layer with a homogeneous cross sectional structure.
- 2. A perpendicular magnetic recording medium according to claim 1, wherein said base is a polyester film.
- 3. A perpendicular magnetic recording medium according to claim 1, further comprising a layer of soft magnetic metal.
- 4. A perpendicular magnetic recording medium according to claim 2 or 3, wherein the degree of curl (Kp), which is expressed by: ##EQU2## is not more than 15%, the symbol "l.sub.0 " indicating the length of a specimen of said medium without curl and the symbols "h.sub.1 " and "h.sub.2 " indicating the deviation of a specimen with curl for both ends of the specimen without curl.
- 5. A perpendicular magnetic recording medium according to claim 1, wherein said particle pattern substantially conforms to FIG. 10 of the accompanying drawing.
- 6. A perpendicular magnetic recording medium according to claim 1, wherein said particle pattern substantially conforms to FIG. 12 of the accompanying drawing.
- 7. A perpendicular magnetic recording medium according to claim 1, wherein said particle pattern substantially conforms to FIG. 13 of the accompanying drawing.
Priority Claims (1)
Number |
Date |
Country |
Kind |
55-174680 |
Dec 1980 |
JPX |
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Parent Case Info
This is division of application Ser. No. 329,822, filed Dec. 11, 1981 and issued on Oct. 4, 1983 as U.S. Pat. No. 4,407,894.
Non-Patent Literature Citations (3)
Entry |
Iwasaki et al, IEEE Transactions on Magnetics, vol. MAG 15, No. 6, 11-79, pp. 1456-1458. |
Iwasaki, IEEE Transactions on Magnetics, vol. MAG 16, No. 1, 1-80, pp. 71-76. |
Iwasaki et al, IEEE Transactions on Magnetics, vol. MAG-14, No. 5, 7-78, pp. 849-851. |
Divisions (1)
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Number |
Date |
Country |
Parent |
329822 |
Dec 1981 |
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