Influence of Substituion on Barium Ferrite Properties

BaFe12-2x(Ni, Zn)xSnxO19 M - type compounds processed by citrate precursor method with substitution level 0.0 Mossbauer spectroscopy and thermomagnetic analysis were used to investigate the magneto - crystalline structure of these hexaferrites. Coercive field intensity Hc, specific saturation magnetic polarisation  Js-m and remanent magnetic polarisation Js-r of ferrite powder specimens were measured. A large change of the coercitity Hc from 330kA/m (x=0.0) to ~70kA/m (x=0.6) was reached as a function of the substitution x. These changes are caused by rearrangement of the Fe3+ ions within the crystalline lattice. Sn4+ ions replace Fe3+ ions on 2b slightly 2a+4f1 sites, while Ni2+ ions occupy 4f2 and 12k sites and Zn2+ ions strongly prefer 4f1 sites.