Assisted magnetic recording medium including a pinning layer and magnetic storage device

Patent metadata

Field	Value
Publication number	US-10360936-B2
Application number	US-201815885013-A
Country	US
Kind code	B2
Filing date	Jan 31, 2018
Priority date	Mar 7, 2017
Publication date	Jul 23, 2019
Grant date	Jul 23, 2019

Abstract

The invention provides a magnetic recording medium with an excellent signal-to-noise ratio during reading by reducing the noise produced during writing of data onto the magnetic recording medium, and increasing the signal level. The assisted magnetic recording medium according to one embodiment comprising a substrate, a base layer, and a magnetic layer composed mainly of an alloy with an L10-type crystal structure, the assisted magnetic recording medium having a pinning layer in contact with the magnetic layer, and the pinning layer including Co or an alloy composed mainly of Co.

First claim

The invention claimed is:

1. An assisted magnetic recording medium comprising a substrate, a base layer, and a magnetic layer composed mainly of an alloy with an L1 0 -type crystal structure, the assisted magnetic recording medium having a pinning layer in contact with the magnetic layer, and the pinning layer including Co or an alloy composed mainly of Co wherein the difference (P Tc −M Tc ) between the Curie temperature of the magnetic material composing the pinning layer (P Tc ) and the Curie temperature of the magnetic material composing the magnetic layer (M Tc ) is 200K or greater.

2. The assisted magnetic recording medium according to claim 1 , wherein the pinning layer pins the magnetization direction of the magnetic particles when magnetic data has been written on the magnetic layer.

3. The assisted magnetic recording medium according to claim 1 , wherein the pinning layer has a granular structure comprising Co or an alloy composed mainly of Co, and at least one oxide selected from the group consisting of SiO 2 , Cr 2 O 3 , TiO 2 , B 2 O 3 , GeO 2 , MgO, Ta 2 O 5 , CoO, Co 3 O 4 , FeO, Fe 2 O 3 and Fe 3 O 4 .

4. The assisted magnetic recording medium according to claim 1 , wherein the layer thickness of the pinning layer is from 0.5 nm to 5 nm.

5. The assisted magnetic recording medium according to claim 1 , which has the pinning layer on the side of the magnetic layer opposite from the substrate side.

6. A magnetic storage device comprising an assisted magnetic recording medium according to claim 1 , a magnetic recording medium driving unit for rotating the assisted magnetic recording medium, a magnetic head that carries out recording and reproduction operations on the assisted magnetic recording medium, a magnetic head driving unit for moving the magnetic head, and a recording/reproduction signal processing system.

Assignees

• Showa Denko Kk

Inventors

• Niwa Kazuya
• Kanbe Tetsuya
• Murakami Yuji
• Zhang Lei
• Shibata Hisato
• Fukushima Takayuki
• Nakajima Satoru
• Yamaguchi Takehiro

Classifications

• G11B5/738

  Physics · mapped topic

• G11B5/012

  Recording on, or reproducing or erasing from, magnetic disks (G11B17/00, G11B19/00 take precedence) · CPC title

• G11B5/1875

  "Composite" pole pieces, i.e. poles composed in some parts of magnetic particles and in some other parts of magnetic metal layers · CPC title

• G11B2005/0021

  Thermally assisted recording using an auxiliary energy source for heating the recording layer locally to assist the magnetization reversal · CPC title

• G11B5/714

  characterised by the dimension of the magnetic particles · CPC title