Tokyo Shibaura Denki Kabushiki Kaisha

Masashi Awa

Isao Suzuki

Hiroshi Endo

Hajime Takeuchi

Takeo Ito

Toshihiko Oguchi

Tadashi Ido

Tatsumi Maeda

Minoru Hashimoto

Masaru Hayashi

Shigeo Iiri

Naoyuki Hirate

A powder for a magnetic recording medium comprising a plurality of magnetic particles and a coating covering the surfaces of the magnetic particles. The coating is a residue resulting from the thermal decomposition of an organic material. The powder is manufactured by applying one or more organic materials to the surfaces of a plurality of magnetic particles by dispersing the magnetic particles in a solution containing the organic material. The magnetic particles, having the organic material as a coating, are separated from the solution, and the magnetic particles are heated to a temperature at which the organic material decomposes.

Powder for magnetic recording media and process for manufacturing the

Barium-ferrite series powders are prepared from an alkaline aqueous solution containing a prescribed ratio of ions of the metals equal to those contained in the powder. In the first stage, the alkaline aqueous solution is heated at a constant volume at 150.degree. to 300.degree. C. to precipitate a precursor of the barium-ferrite series powder. Then, the precursor is baked at 700.degree. to 1,000.degree. C. to crystallize the precursor.

Method of producing barium-ferrite series powder

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Yokohama, Japan

Masashi Awa