Complex impedance spectroscopy studies of BaTiO_3 Ceramic with 10 BaFe_(12)O_(19) Substitution

摘要

Barium titanate with 10% barium ferrite substitution (BaTiO_3-BaFe_(12)O_(19)) has been synthesized by the solid state reaction route. Formation of the BaFe_(12)O_(19) phase confirmed its existence in the composite. Impedance spectroscopy study of the composite sample was performed at different temperatures of 25, 40, 80, 120 and 160°C. BaFe_(12)O_(19) substituted sample shows a single semicircle at lower temperature and two overlapped arcs at 120 and 160°C due to grain and grain boundary. The impedance plots were fitted based on a parallel R-CPE circuit. The grain boundary resistance behaves like the positive temperature coefficient of resistance (PTCR) for donor-doped BaTiO_3 semiconductor. The highest capacitance is contributed by the grain boundary at 80°C.