Dynamic magnetic information storage or retrieval – Record medium – Disk
Reexamination Certificate
2011-01-25
2011-01-25
Evans, Jefferson (Department: 2627)
Dynamic magnetic information storage or retrieval
Record medium
Disk
C428S827000, C428S829000, C428S832200
Reexamination Certificate
active
07876530
ABSTRACT:
In one embodiment, a magnetic recording medium comprises an underlying film, a magnetic film and a protective film formed in this order on a substrate. The magnetic film is a cobalt-base alloy film containing chromium and has a plurality of magnetic layers stacked without interposition of any non-magnetic layer. The plural magnetic layers comprise first, second and third magnetic layers. The first magnetic layer is disposed between the underlying film and the second magnetic layer. The second magnetic layer is disposed between the first magnetic layer and the third magnetic layer. The third magnetic layer is disposed between the second magnetic layer and the protective film. The concentration of chromium contained in the first magnetic layer is lower than that of chromium contained in the second magnetic layer. The thickness of the first magnetic layer is smaller than that of the second magnetic layer. The magnetic layers which overlie the first magnetic layer further contain platinum and boron. The concentration of chromium contained in the third magnetic layer is lower than that of chromium contained in the second magnetic layer.
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Hinoue Tatsuya
Inagaki Jo
Kashiwase Hidekazu
Suzuki Hiroyuki
Suzuki, legal representative Masae
Evans Jefferson
Hitachi Global Storage Technologies - Netherlands B.V.
Zilka-Kotab, PC
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