Improvements of magnetic properties of Sr ferrite magnets by substitutions of La and Co

The effect of the simultaneous partial substitution of Co/sup 2+/ for Fe/sup 3+/ and of La/sup 3+/ for Sr/sup 2+/ ion in Sr ferrite on the magnetic properties of anisotropic Sr ferrite magnets was investigated. It was found that the coercive force of Sr ferrite magnets is increased without significant decrease in residual flux density by La-Co substitution. Temperature coefficients of coercive force were found to be also improved by La-Co substitution.