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US 11,521,649 B2Granted
Method of producing a magnetic powder and method of producing a magnetic recording medium
AssigneeSony Corporation
InventorsAtsushi Muramatsu, Masafumi Nakaya, Masaru Terakawa, Satoru Abe, Natsuki Toyosawa, Katsunori Maeshima
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Abstract
A method of producing a magnetic powder includes: performing heat treatment on first particles that contain triiron tetraoxide to prepare second particles that contain ε-iron oxide.
Claims8
A method of producing a magnetic powder, comprising:
- preparing a plurality of first particles by a liquid-phase thermal decomposition method, wherein the first particles include triiron tetraoxide, and wherein the first particles have an average particle size from 8 nm to 25 nm;
- performing silica coating treatment on the first particles;
- performing heat treatment on the first particles to prepare a plurality of second particles that contain ε-iron oxide with an average particle size of the second particles from 8 nm to 25 nm;
- and
- removing silica coating on the second particles after heat treatment.
2 more elements
A method of producing a magnetic recording medium, comprising:
- preparing a plurality of first particles by a liquid-phase thermal decomposition method, wherein the first particles include triiron tetraoxide, and wherein the first particles have an average particle size from 8 nm to 25 nm;
- performing silica coating treatment on the first particles;
- performing heat treatment on the first particles to prepare a plurality of second particles that contain ε-iron oxide with an average particle size of the second particles from 8 nm to 25 nm;
- removing silica coating on the second particles after heat treatment and
- forming a recording layer by using the prepared second particles.
2 more elements
Dependencies are inferred from the claim text.