PURPOSE: To realize the reduction of the temperature coefficient of coercive force, without decreasing the rectangularity ratio of ferrite magnetic powder of compound type hexagonal system.
CONSTITUTION: Hexagonal system ferrite and spinel ferrite are compounded to obtain the title magnetic powder. The compound type magnetic powder contains 0.02-0.95 of Li element in 1mol of alkaline earth ions (one kind selected out of Ba, Sr, Pb and Ca) which are constituent elements of the hexagonal system ferrite. Further it is a characteristic that the ratio of the spinel ferrite phase to the hexagonal system ferrite phase is less than 0.1-2.0mols to hexagonal system ferrite of 1mol. The compound type magnetic powder is dispersed and contained in a magnetic layer to obtain magnetic recording medium. As the result of the above compounding, the rectangularity ratio of magnetic powder can be restrained, and the temperature stability of coercive force also is increased, so that highly reliable magnetic recording function is exhibited.
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MAEDA TATSUMI
KURISU TOSHIHARU
OGAWA ETSUJI
