Characterization of BaFe12-2xCoxZrxO19 (0≤x≤0.5) synthesised by citrate gel precursor route

The properties of Co-Zr substituted barium hexaferrite, synthesized by a citrate gel route, have been studied and optimized for recording media. The large variation in coercivity and other magnetic properties has been examined in the light of reduction in anisotropy, variation in particle size and plausible distribution of cations on the five magnetic sublattices. Moessbauer spectroscopy suggests the presence of superparamagnetic particles in samples heated at 1170 K. These studies also suggest that substitutions in Co-Zr system are different from those in similar systems such as Co-Ti substituted hexaferrites. (orig.)