Barium titanate–nickel ferrite, barium titanate–zinc ferrite, and barium titanate–nickel-zinc ferrite composite powders prepared by thermal decomposition method were characterized by Raman spectroscopy, scanning electron microscopy (SEM), and X-Ray powder diffraction (XRPD). Obtained materials consisted of pure perovskite and spinel phases. Scanning electron microscopy analyses revealed that the morphology of investigated samples is not uniform, and aggregation of individual particles is a dominant process in all cases. Raman spectroscopy suggested that in the case of barium titanate–nickel ferrite, the coupling of two phases occurred and the core-shell structure was partially formed, while for barium titanate–zinc ferrite the coupling effect is less pronounced
