发明名称 |
Perpendicular magnetic recording medium and magnetic storage apparatus |
摘要 |
A perpendicular magnetic recording medium includes a perpendicular magnetic layer provided above a nonmagnetic substrate, and a protection layer provided on the perpendicular magnetic layer. The perpendicular magnetic layer has an hcp structure, and includes stacked layers having a (0002) crystal plane oriented parallel to a surface of the nonmagnetic substrate. An uppermost layer amongst the stacked layers includes polycrystal grains selected from a CoCr-base alloy, a CoPt-base alloy, a CoCrPt-base alloy, and a CoPtCr-base alloy. The protection layer makes contact with the uppermost layer of the perpendicular magnetic layer, and includes a single graphene layer or a graphene stack, and an amorphous carbon layer. The single graphene layer or the graphene stack is bonded in parallel to a (0002) crystal plane of the polycrystal grains. |
申请公布号 |
US9640213(B2) |
申请公布日期 |
2017.05.02 |
申请号 |
US201514935529 |
申请日期 |
2015.11.09 |
申请人 |
SHOWA DENKO K.K.;JAPAN ATOMIC ENERGY AGENCY |
发明人 |
Hasegawa Kota;Ukai Takahiro;Yamakawa Eishin;Entani Shiro;Sakai Seiji |
分类号 |
G11B5/66;G11B5/72;G11B5/82 |
主分类号 |
G11B5/66 |
代理机构 |
IPUSA, PLLC |
代理人 |
IPUSA, PLLC |
主权项 |
1. A perpendicular magnetic recording medium comprising:
a nonmagnetic substrate; a perpendicular magnetic layer provided above the nonmagnetic substrate; and a protection layer provided on the perpendicular magnetic layer, wherein the perpendicular magnetic layer has a hexagonal close packed structure, and includes a plurality of stacked layers having a (0002) crystal plane oriented parallel to a surface of the nonmagnetic substrate, wherein an uppermost layer, amongst the plurality of stacked layers of the perpendicular magnetic layer, has a non-granular structure and includes polycrystal grains but does not include an oxide, nitride or carbide isolating the polycrystal grains, wherein the polycrystal grains are selected from a group consisting of a CoCr-base alloy, a CoPt-base alloy, a CoCrPt-base alloy, and a CoPtCr-base alloy, wherein the protection layer makes contact with the uppermost layer of the perpendicular magnetic layer, and includes a single graphene layer or a graphene stack, and an amorphous carbon layer, wherein the single graphene layer or the graphene stack is bonded in parallel to a (0002) crystal plane of the polycrystal grains, and wherein the graphene stack includes two or more and ten or less graphene layers that are stacked. |
地址 |
Tokyo JP |