Complex Impedance Spectroscopy Studies of BaTiO sub(3) Ceramic with 10% BaFe sub(12) O sub(19) Substitution

Barium titanate with 10% barium ferrite substitution (BaTiO sub(3)-BaFe sub(12) O sub(19)) has been synthesized by the solid state reaction route. Formation of the BaFe sub(12) O sub(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 [degrees]C. BaFe sub(12) O sub(19) substituted sample shows a single semicircle at lower temperature and two overlapped arcs at 120 and 160 [degrees]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 resistivity (PTCR) for donor-doped BaTiO sub(3) semiconductor. The highest capacitance is contributed by the grain boundary at 80 [degrees]C.