IP Library › Granted Patent US 7,335,393
Granted Patent B2
US 7,335,393 · App. 10/896,079 · Granted Feb 26, 2008

Magnetic particle, its production method, magnetic recording medium and its production method

View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 7,335,393
App. No.
10/896,079
Granted
Feb 26, 2008
Kind
B2
Abstract

The present invention relates to a method of producing a magnetic particle including forming a layer containing an alloy particle that can form CuAu type or Cu 3 Au type hard magnetic order alloy phase on a support, oxidizing the layer, and annealing the layer in non-oxidizing atmosphere. The invention also relates to a method of producing a magnetic particle including producing an alloy particle that can form hard magnetic order alloy phase, oxidizing the alloy particle, and annealing the particle in non-oxidizing atmosphere, and a magnetic particle produced by the foregoing production method. Further, the invention relates to a magnetic recording medium comprising a magnetic layer containing a magnetic particle and a method of producing a magnetic recording medium including forming a layer containing an alloy that can form the foregoing hard magnetic order alloy phase, oxidizing the layer, and annealing the layer in non-oxidizing atmosphere.

Claims (6)

1. A method of producing a magnetic recording medium including forming on a support a layer containing an alloy that can form a hard magnetic alloy phase having a CuAu or Cu 3 Au ordered structure, oxidizing the layer, and annealing the layer in a reducing atmosphere at an annealing temperature of 450° C. or lower and a retention time of 10 minutes or shorter.

2. The method of producing a magnetic recording medium according to claim 1 , which comprises forming on a support a layer containing an alloy selected from the group consisting of FeNi, FePd, FePt, CoPt and CoAu.

3. The method of producing a magnetic recording medium according to claim 1 , which comprises forming on a support a layer containing an alloy selected from the group consisting of Ni 3 Fe, FePd 3 , Fe 3 Pt, FePt 3 , CoPt 3 , Ni 3 Pt, CrPt 3 and Ni 3 Mn.

4. The method according to claim 1 , wherein the reducing atmosphere includes H 2 .

5. The method according to claim 1 , wherein the alloy is produced by a liquid phase method.

6. The method according to claim 1 , wherein the alloy is produced by a reverse micelle method.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Feb 15, 2007
From: FUJIFILM HOLDINGS CORPORATION (FORMERLY FUJI PHOTO FILM CO., LTD.)
To: FUJIFILM CORPORATION
Reel/Frame 018904/0001 →