发明名称 |
Magnetic recording medium for perpendicular magnetic recording |
摘要 |
A perpendicular recording medium having a perpendicular magnetic recording layer and a magnetically soft underlayer structure disposed beneath the recording layer. The soft underlayer structure includes at least first and second soft magnetic layers having different magnetic permeabilities to create a magnetic permeability gradient in the soft underlayer structure. One or more of the soft magnetic layers can be antiparallel coupled. The soft underlayer structure of the present invention having a magnetic permeability gradient advantageously leads to reduced adjacent track erasure (ATE) while maintaining good overwrite (OW) properties. |
申请公布号 |
US9005781(B2) |
申请公布日期 |
2015.04.14 |
申请号 |
US201213620324 |
申请日期 |
2012.09.14 |
申请人 |
Seagate Technology LLC |
发明人 |
Zhou Jianing;Acharya B. Ramamurthy;Abarra E. Noel;Choe Gunn |
分类号 |
G11B5/667;G11B5/82 |
主分类号 |
G11B5/667 |
代理机构 |
Hollingsworth Davis, LLC |
代理人 |
Hollingsworth Davis, LLC |
主权项 |
1. A magnetic stack, comprising:
a substrate; a soft underlayer structure disposed over the substrate, the soft underlayer structure comprising:
a first anti-parallel coupled soft magnetic layered unit having a first magnetic permeability;a second anti-parallel coupled soft magnetic layered unit that is disposed over said first anti-parallel coupled soft magnetic layered unit and having a second magnetic permeability, wherein the first magnetic permeability is different than the second magnetic permeability; anda third soft magnetic layer having a third magnetic permeability, wherein the third magnetic permeability is different than either of the first and second magnetic permeabilities. |
地址 |
Cupertino CA US |