A Study of Micro-Structure and Magnetic Properties of γ-Fe₂O₃ Surface Coated with BaFe₁₂O₁₉

A series of γ-Fe₂O₃ coated with different constants of BaFe₁₂O₁₉ have been prepared by surface coating method. With the aid of XRD, analysed the structures of these composite particles. The results show, at high temperature, the diffusion of ions leads to the formation of a transition layer between two phases, γ-Fe₂O₃ and BaFe₁₂O₁₉. The transition layer leads to a delay of the variation of magnetic properties with relation to that of BaFe₁₂O₁₉%.