Tdk Electronics Company, Limited

Hiroto Saguchi

Masashi Hayama

Kenji Hirabayashi

Keitaro Sakai

A magnetic powder for a magnetic recording medium which is a cobalt-adsorbed magnetic iron oxide having a coercive force of 1000 Oe or more and a ratio of a coercive force at -196.degree. C. to a coercive force at room temperature of 3 or less.

Magnetic powder for magnetic recording medium

A magnetic recording medium comprises a substrate coated with a magnetic composition comprising a cobalt adsorbed iron oxide powder with a phosphoric ester type anionic surfactant at a ratio of 2 wt. % or more and a binder at a ratio of said iron oxide powder to said binder of 4 or more. A magnetic recording medium has a coercive force Hc of 950 to 1200 Oe and a residual magnetic flux .phi..sub.r of 0.35 to 0.6 maxwell.

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Tokyo, Japan

Hiroto Saguchi