Invention Grant
- Patent Title: Thermally assisted recording media and system
- Patent Title (中): 热辅助记录媒体和系统
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Application No.: US12608232Application Date: 2009-10-29
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Publication No.: US08089829B2Publication Date: 2012-01-03
- Inventor: Fumiko Akagi , Masukazu Igarashi , Hiroaki Nemoto , Takayuki Ichihara
- Applicant: Fumiko Akagi , Masukazu Igarashi , Hiroaki Nemoto , Takayuki Ichihara
- Applicant Address: JP Tokyo
- Assignee: Hitachi, Ltd.
- Current Assignee: Hitachi, Ltd.
- Current Assignee Address: JP Tokyo
- Agency: Antonelli, Terry, Stout & Kraus, LLP.
- Priority: JP2008-281576 20081031
- Main IPC: G11B11/00
- IPC: G11B11/00

Abstract:
A thermally assisted magnetic recording medium includes a substrate and at least two, i.e., first and second magnetic recording layers. These layers are hard magnetic layers and contain magnetic grains and a non-magnetic substance magnetically segregating the magnetic grains at grain boundaries. The first magnetic recording layer has a magnetic anisotropy energy Ku1, a grain volume v1, and energy for maintaining its recording magnetization Ku1v1; the second magnetic recording layer has a magnetic anisotropy energy Ku2, a grain volume v2, and energy for maintaining its recording magnetization Ku2v2; and the ratio Ku1v1/kBT of Ku1v1 to a thermal fluctuation energy kBT, where kB represents a Boltzmann constant and T represents an absolute temperature, and the ratio Ku2v2/kBT of Ku2v2 to kBT satisfy the following conditions: Ku1v1/kBT is larger than Ku2v2/kBT at room temperature, but is smaller than Ku2v2/kBT at temperatures around the Curie temperature of the first magnetic recording layer.
Public/Granted literature
- US20100110576A1 THERMALLY ASSISTED RECORDING MEDIA AND SYSTEM Public/Granted day:2010-05-06
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