发明授权
- 专利标题: Perpendicular magnetic recording medium with exchange-spring structure having multiple exchange-spring layers and recording system for the medium
- 专利标题(中): 具有交换弹簧结构的垂直磁记录介质具有多个交换弹簧层和用于介质的记录系统
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申请号: US11676299申请日: 2007-02-18
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公开(公告)号: US07572526B2公开(公告)日: 2009-08-11
- 发明人: Andreas Klaus Berger , Eric E. Fullerton , Byron Hassberg Lengsfield, III
- 申请人: Andreas Klaus Berger , Eric E. Fullerton , Byron Hassberg Lengsfield, III
- 申请人地址: NL Amsterdam
- 专利权人: Hitachi Global Storage Technologies Netherlands B.V.
- 当前专利权人: Hitachi Global Storage Technologies Netherlands B.V.
- 当前专利权人地址: NL Amsterdam
- 代理商 Thomas R. Berthold
- 主分类号: G11B5/66
- IPC分类号: G11B5/66 ; G11B5/667 ; G11B5/716 ; G11B5/673
摘要:
A perpendicular magnetic recording system uses an exchange-spring type of perpendicular magnetic recording medium. The medium has a recording layer (RL) that includes a lower media layer (ML) and a multilayer exchange-spring layer (ESL) above the ML. The high anisotropy field (high-Hk) lower ML and the multilayer ESL are exchange-coupled across a coupling layer. The multilayer ESL has at least two ESLs separated by a coupling layer, with each of the ESLs having an Hk substantially less than the Hk of the ML. The exchange-spring structure with the multilayer ESL takes advantage of the fact that the write field magnitude and write field gradient vary as a function of distance from the write pole. The thicknesses and Hk values of each of the ESLs can be independently varied to optimize the overall recording performance of the medium.