FERRITE POWDER FOR HIGH DENSITY RECORDING HAVING SMALL TEMPERATURE DEPENDENCY OF COERCIVE FORCE

摘要

PURPOSE:To obtain a ferrite powder for high density recording having small temperature dependency of coercive force by specifying a composition of the ferrite powder with the general formula containing Ba, V, Mn, O and Fe and enabling control of a ferrite powder for high density recording in controlled reaction conditions. CONSTITUTION:The title ferrite powder formed of a composition expressed by formula l (M is a metal element selected from Ba, Sr, Pb and Ca; M' is metal element selected from V, Sn, Ti, Zr, W and Nb; M'' is a metal element selected from Zn, Cu, Co, Ni and Mg, n is 6.3-9; x is 0.01-0.3; y is 0-0.2; z is 0-0.2) and produced so that temperature dependency thetaHC of coercive force expressed by formula II is -5-2(Oe/ deg.C) by controlling the reaction conditions. The above-mentioned ferrite powder has small temperature dependency of coercive force as mentioned above.