Study on structural and magnetic properties of nanosized M-type Ba-hexaferrites synthesized by urea assisted citrate precursor route

The correlation between distribution of cations over five crystallographic positions and magnetic properties of Ba-hexaferrites in the coupled substitution of magnetic Co2+ and non-magnetic Zr4+ for Fe3+ is investigated by urea assisted citrate precursor route. BET surface area of sample is 34.86 m2/g. Dopant ions largely prefer 4f1 and 2a sites up to 0.8 level while substitution at 12k, 4f1 and 2a sites is indicated at higher concentrations. The coercive force is steeply reduced from 5017 to 589 Oe with increasing Co-Zr contents but net magnetization is nearly constant (MS = 50.38-63.54 emu/g).