Haruo Andoh

Magnetic recording medium and process

A magnetic recording medium which comprises a base and a magnetic layer of a magnetic coating composition comprising magnetic particles and a binder provided on said base, characterized in that the magnetic coating composition further comprises a dialkylsulfosuccinate.

Time variation of coercivity in cobalt-contained iron oxides particles

Abstract A variation of coercivity in annealing was examined for two different types of cobalt-contained iron oxide particles. The increase of coercivity by annealing cobalt-substituted iron oxides was caused by the induced magnetic anisotropy. The stable coercivity of cobalt-epitaxial iron oxides resulted from the long relaxation time of the cobalt-ferrite crystallized on the oxides.

Formation of Cobalt-Epitaxial Iron Oxides and Their Magnetic Properties

3,947,373 3/i976 Sobajima et al. .................. 252/63.2 4,083,727 4/1978 Andrus et al. ........................ 106/39 4,133,677 1/1979 Matsui et al. ..... ... 75/0.5 AA 4,650,72 3/1987 Hirose ................................. 428/323 4,668,355 5/1987 Lin ........ ... 204/146 4,690,768 9/1987 Kamiyama ... 252/62.58 4,697,744 10/1987 Wada et al. ........................... 241/20 4,698,140 10/1987 Crane et al. ...... ... 204/146 4,814,239 3/1989 Inoue et al. ...... ... 428/694 4,816, 119 3/1989 Rauch et al. .......................... 204/29 4,816,311 3/1989 Lenhart ................................. 428/64 4,820,565 4/1989 Funahashi et al. ................... 428/64 4,820,581 4/1989 Saito et al. ............... ... 428/323 4,820,584 4/1989 Morita et al. ....................... 428/336