# US 10,504,547 B2 · Perpendicular magnetic recording medium

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- Number: US 10,504,547 B2
- Document ID: US10504547B2
- Status: Granted
- Kind: B2
- Application number: 15/027,985
- Filed: 2015-01-13
- Published: 2016-09-01
- Granted: 2019-12-10
- Earliest claimed: 2014-01-23
- Assignees: Fuji Electric Co., Ltd.
- Applicants: Fuji Electric Co., Ltd.
- Inventors: Hitoshi Nakata; Takehito Shimatsu
- Web page: https://patentgrep.com/patent/US10504547B2

## CPC

- G11B 5/653: {containing Fe or Ni (containing Co G11B5/656; containing inorganic, non-oxide compounds of Si, N, P, B, H or C G11B5/657; containing oxygen G11B5/658)}
- G11B 5/66: the record carriers consisting of several layers
- G11B 5/7379: {Seed layer, e.g. at least one non-magnetic layer is specifically adapted as a seed or seeding layer}
- G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R)

## Abstract

The purpose of the present invention is to provide a magnetic recording medium including a first magnetic recording layer having a large coercive force and a granular structure in which magnetic crystal grains are well separated from each other. The magnetic recording medium of the present invention includes a non-magnetic substrate, a first seed layer, and a first magnetic recording layer formed on the first seed layer, wherein the first seed layer includes Pt, the first magnetic recording layer includes one or more magnetic layers, the magnetic layer in contact with the first seed layer includes Fe, Pt and Ti, and the magnetic layer in contact with the first seed layer has a granular structure consisting of magnetic crystal grains of a L10 type ordered alloy including Fe and Pt, and a non-magnetic grain boundary including Ti.

## Claims

### Claim 1

A magnetic recording medium comprising a non-magnetic substrate, a first seed layer, and a first magnetic recording layer formed on the first seed layer, wherein: the first seed layer comprises Pt;
the first magnetic recording layer comprises one or more magnetic layers, the magnetic layer in contact with the first seed layer comprises Fe, Pt and Ti; and the magnetic layer in contact with the first seed layer has a granular structure consisting of magnetic crystal grains of a L10 type ordered alloy comprising Fe and Pt, and non-magnetic grain boundaries consisting of Ti.

### Claim 2 (depends on 1)

The magnetic recording medium according to claim 1, wherein the magnetic layer in contact with the first seed layer comprises 4 at % or more and 12 at % or less of Ti, based on the total number of atoms.

### Claim 3 (depends on 1)

The magnetic recording medium according to claim 1, wherein the L10 type ordered alloy further comprises at least one element selected from the group consisting of Ni, Mn, Ag, Au and Cr.

### Claim 4 (depends on 1)

The magnetic recording medium according to claim 1, wherein the first magnetic recording layer consists of one magnetic layer.

### Claim 5 (depends on 1)

The magnetic recording medium according to claim 1, further comprising a second seed layer and a second magnetic recording layer between the non-magnetic substrate and the first seed layer, wherein the second magnetic recording layer is in contact with the first seed layer.

### Claim 6 (depends on 1)

The magnetic recording medium according to claim 1, further comprising one or more layers selected from the group consisting of a heat sink layer, an adhesive layer, a soft magnetic backing layer, and a base layer, between the non-magnetic substrate and the first seed layer.