IP Library Granted Patent US 6,858,320
Granted Patent B2
US 6,858,320 · App. 10/153,887 · Granted Feb 22, 2005

Perpendicular magnetic recording medium

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Quick Facts
Patent No.
US 6,858,320
App. No.
10/153,887
Granted
Feb 22, 2005
Kind
B2
Abstract

A performance of a perpendicular magnetic recording medium, such as an increase in output or a decrease in noise, is improved by providing a good orientation of a magnetic recording layer in the perpendicular magnetic recording medium and by reducing an amount of an initial growth layer in the magnetic recording layer. The perpendicular magnetic recording medium includes an under layer, a magnetic recording layer, a protective film, and a liquid lubrication layer, which are sequentially provided on a non-magnetic substrate. The under layer contains non-magnetic NiFeCr or a permalloy-based soft magnetic material.

Claims (27)

1. A perpendicular magnetic recording medium, comprising:

a non-magnetic substrate;

a under layer comprising non-magnetic NiFeCr;

a seed layer, between the non-magnetic substrate and the under layer, comprising Ta or Ti;

a magnetic recording layer;

a protective film; and

a liquid lubrication layer, wherein the under layer, the magnetic recording layer, the protective film, and the liquid lubrication layer are sequentially provided on the non-magnetic substrate.

2. The perpendicular magnetic recording medium according to claim 1 , wherein the seed layer comprises a film thickness of 10 nm or less.

3. The perpendicular magnetic recording medium according to claim 1 , further comprising:

an intermediate layer, between the under layer and the magnetic recording layer, having a non-magnetic material comprising CoCr, CoCrB, Ru, or Pd.

4. The perpendicular magnetic recording medium according to claim 2 , further comprising:

an intermediate layer, between the under layer and the magnetic recording layer, having a non-magnetic material comprising CoCr, CoCrB, Ru, or Pd.

5. A perpendicular magnetic recording medium, comprising:

a non-magnetic substrate;

a soft magnetic backing layer;

an under layer including non-magnetic NiFeCr;

a magnetic recording layer;

a protective film; and

a liquid lubrication layer,

wherein the soft magnetic backing layer, the under layer, the magnetic recording layer, the protective film, and the liquid lubrication layer are sequentially positioned on the non-magnetic substrate.

6. The perpendicular magnetic recording medium according to claim 5 , further comprising:

an intermediate layer, between the under layer and the magnetic recording layer, having a non-magnetic material comprising CoCr, CoCrB, Ru, or Pd.

7. The perpendicular magnetic recording medium according to claim 5 , wherein the non-magnetic NiFeCr includes a substantially face-centered cubic lattice structure.

8. The perpendicular magnetic recording medium according to claim 5 , further comprising:

a seed layer between the non-magnetic substrate and the under layer, the seed layer including at least one of Ta and Ti.

9. The perpendicular magnetic recording medium according to claim 8 , further comprising:

an intermediate layer between the under layer and the magnetic recording layer, the intermediate layer having a non-magnetic material including at least one of CoCr, CoCrB, Ru, and Pd.

Assignments (5)
CHANGE OF NAME Recorded Oct 10, 2011
From: FUJI ELECTRIC DEVICE TECHNOLOGY CO., LTD.
To: FUJI ELECTRIC CO., LTD.
Reel/Frame 027249/0159 →
MERGER Recorded Oct 10, 2011
From: FUJI ELECTRIC DEVICE TECHNOLOGY CO., LTD. (MERGER)
To: FUJI ELECTRIC CO., LTD.
Reel/Frame 027288/0820 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 14, 2009
From: FUJI ELECTRIC HOLDINGS CO., LTD.
To: FUJI ELECTRIC DEVICE TECHNOLOGY CO., LTD.
Reel/Frame 022951/0404 →
CORRECTIVE ASSIGNMENT TO CORRECT THE ASSIGNEE FROM FUJI ELECTRIC DEVICE TECHNOLOGY CO., LTD. TO FUJI ELECTRIC HOLDINGS CO., LTD. PREVIOUSLY RECORDED ON REEL 022902 FRAME 0975. ASSIGNOR(S) HEREBY CONFIRMS THE CHANGE OF NAME. Recorded Jul 9, 2009
From: FUJI ELECTRIC CO., LTD.
To: FUJI ELECTRIC HOLDINGS CO., LTD.
Reel/Frame 022928/0918 →
CHANGE OF NAME Recorded Jul 2, 2009
From: FUJI ELECTRIC CO., LTD.
To: FUJI ELECTRIC DEVICE TECHNOLOGY CO., LTD.
Reel/Frame 022902/0975 →