Synthesis and the magnetic characterization of iridium–cobalt substituted calcium hexaferrites

M-type hexagonal ferrite powder with partial substitution lr4++Co2+ has been synthesized by chemical-coprecipitation technique. The saturation magnetization Ms decreases linearly from 69.8 to 40.3 emu/g with increasing doping content from 0.5 to 1. The Coerecivity sharply drops for x=0.5, which can be explained by the decrease of the anisotropy constant K1 Curie temperature Tc decreases linearly with increasing ‘x’. Crystallographic studies were explained on the cation distribution consistent with Gorter spin model of parallel alignment.