Preparation and properties of the CoFe2O4–Nb–Pb(Zr,Ti)O3 multiferroic composites prepared in situ by gel-combustion method

Di-phase magnetoelectric composites formed by magnetic CoFe2O4 and ferroelectric Nb–Pb(Zr,Ti)O3 were prepared by citrate–nitrate combustion method technique by using Nb–Pb(Zr,Ti)O3 template powders prepared by mixed oxides. Pure di-phase powder composites with a good crystallinity were obtained after the calcination step. The purity was maintained by sintering at temperature of 1100 °C/2 h, which ensured limited reactions at interfaces, while by sintering at 1250 °C/2 h, small amounts of secondary phases resulted. The method allowed to produce di-phase ceramics with homogeneous microstructures and a very good mixing of the two phases. The dielectric and magnetic investigations at room temperature confirmed the formation of composite ceramics with both dielectric and magnetic properties at room temperature, with permittivity and magnetization resulted as sum properties from the parent Pb(Zr,Ti)O3 and ferrite phases.