Magnetic recording medium with multiple soft underlayers and magnetic recording apparatus for use therewith
US-2024135969-A1 · Apr 25, 2024 · US
Perpendicular magnetic recording medium
US9028984B2 · US · B2
| Field | Value |
|---|---|
| Publication number | US-9028984-B2 |
| Application number | US-59580508-A |
| Country | US |
| Kind code | B2 |
| Filing date | Apr 11, 2008 |
| Priority date | Apr 13, 2007 |
| Publication date | May 12, 2015 |
| Grant date | May 12, 2015 |
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Abstract
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A perpendicular magnetic recording medium includes a nonmagnetic substrate, and a soft magnetic layer, a first orientation control layer, a second orientation control layer, a nonmagnetic intermediate layer, a magnetic recording layer, and a protective layer layered sequentially on the nonmagnetic substrate. The first orientation control layer includes a thin film having a face-centered cubic (fcc) structure. The magnetic recording layer includes a thin film layer having ferromagnetic crystal grains and nonmagnetic grain boundaries surrounding the ferromagnetic crystal grains, the ferromagnetic crystal grains including a CoPt alloy having ferromagnetic properties, and the nonmagnetic grain boundaries including an oxide or a nitride. The nonmagnetic intermediate layer includes a thin film containing Ru. The second orientation control layer includes an alloy thin film having an element selected from among Ni and Fe and having the fcc structure, the second orientation control layer having a saturation magnetic flux density Bs of 1 T or lower.
First claim
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The invention claimed is: 1. A perpendicular magnetic recording medium, comprising: a nonmagnetic substrate; and a soft magnetic layer, a first orientation control layer, a second orientation control layer, a nonmagnetic intermediate layer, a magnetic recording layer, and a protective layer, layered sequentially on the nonmagnetic substrate, wherein the first orientation control layer is formed directly on the soft magnetic layer, the first orientation control layer includes…
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- G11B5/667Primary
Physics · mapped topic
Physics · mapped topic
Physics · mapped topic
Physics · mapped topic
Physics · mapped topic
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Frequently asked questions
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- What does patent US9028984B2 cover?
- A perpendicular magnetic recording medium includes a nonmagnetic substrate, and a soft magnetic layer, a first orientation control layer, a second orientation control layer, a nonmagnetic intermediate layer, a magnetic recording layer, and a protective layer layered sequentially on the nonmagnetic substrate. The first orientation control layer includes a thin film having a face-centered cubic (…
- Who is the assignee on this patent?
- Sakai Yasushi, Takenoiri Shunji, Fuji Electric Co Ltd
- What technology area does this patent fall under?
- Primary CPC classification G11B5/667. Mapped technology areas include Physics.
- When was this patent published?
- Publication date Tue May 12 2015 00:00:00 GMT+0000 (Coordinated Universal Time) (B2). Legal status and post-grant events are not shown on this page.
- What related patents are in patentsdb?
- We list 8 related publications on this page (citations in our corpus or others sharing the same primary CPC).