Invention Grant
- Patent Title: Magnetic recording medium and magnetic recording and reproducing device
- Patent Title (中): 磁记录介质和磁记录和再现装置
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Application No.: US12544599Application Date: 2009-08-20
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Publication No.: US07976965B2Publication Date: 2011-07-12
- Inventor: Kenji Shimizu , Junichi Kishimoto
- Applicant: Kenji Shimizu , Junichi Kishimoto
- Applicant Address: JP Tokyo
- Assignee: Showa Denko K.K.
- Current Assignee: Showa Denko K.K.
- Current Assignee Address: JP Tokyo
- Agency: Sughrue Mion, PLLC
- Priority: JP2008-213469 20080822
- Main IPC: G11B5/66
- IPC: G11B5/66

Abstract:
A magnetic recording medium comprises a nonmagnetic substrate on which is disposed at least a vertical magnetic layer. The vertical magnetic layer comprises at least three layers including a lower layer, an intermediate layer and an upper layer from the substrate side. The lower, intermediate and upper magnetic layers are bound by ferro-coupling and are constituted of magnetic particles which are columnar crystals extending continuously from the lower layer to the upper layer. A nonmagnetic layer is between the lower and intermediate magnetic layers or between the intermediate and upper magnetic layers. The upper layer has a magnetic anisotropic constant (Ku) from 0.8×106 to 4×106 (erg/cc), the intermediate layer has a magnetic anisotropic constant (Ku) from 2×106 to 7×106 (erg/cc) and the lower layer has a magnetic anisotropic constant (Ku) from 1×106 to 4×106 (erg/cc).
Public/Granted literature
- US20100046116A1 MAGNETIC RECORDING MEDIUM AND MAGNETIC RECORDING AND REPRODUCING DEVICE Public/Granted day:2010-02-25
Information query
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