FERRITE MAGNET POWDER AND MAGNET USING SAID MAGNET POWDER, AND METHOD FOR PREPARING THEM

摘要

An La-Co ferrite magnet powder, in which Sr and Fe are replaced with La and Co, respectively, is made by carrying out a calcination process at a temperature higher than 1300 DEG C and equal to or lover than 1450 DEG C. Fe has a magnetic moment oriented upwardly with respect to a crystal c-axis at a number of sites thereof, and also has an opposite magnetic moment oriented downwardly with respect to the crystal c-axis at another number of sites thereof. And Fe is replaced with Co at the greater number of sites thereof. As a result, high coercivity is attained. In this manner, coercivity can be increased while suppressing decrease in saturation magnetization sigma S.