| 摘要 |
Magnetic recording medium conventionally utilizes the in-plane magnetization mode, but, recently, the perpendicular magnetization mode utilizing the perpendicular anistropy of an hcp cobalt alloy layer, in which C axis is oriented normal to the layer surface, is proposed. The known perpendicular magnetic recording medium has been produced by an RF sputtering, but such medium is of too low flexibility to use it in the form of a magnetic tape. In addition, the production rate of the perpendicular magnetic recording medium by RF sputtering is very low. The perpendicular magnetic recording medium is very flexible due to particle pattern (FIGS. 10, 12 and 13) completely distinct from the conventional columnar pattern (FIGS. 8 and 11). In addition, the production rate is high, because the base (20) is located beside a space between the targets (T1, T2) of a sputtering device and further the magnetic field is generated perpendicularly to the sputtering surfaces (T1s, T2s) by a field coil (31) or magnets (32, 33). The present invention makes it possible to commercially produce the perpendicular magnetic recording medium, especially in the tape form.
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