Dielectric and magnetic properties of multiferroic BiFeO3 ceramics sintered with the powders prepared by hydrothermal method

Abstract BiFeO 3 ceramics were sintered in the temperature range of 700–900 °C by using the pure BiFeO 3 powders hydrothermally synthesized at 250 °C. The low reaction temperature and low sintering temperature prevent the element volatilization and phase decomposition. The ceramics sintered at 800 and 850 °C exhibit much dense microstructure with clear grains and grain boundaries. They also show high dielectric constant, dielectric dispersion and low loss tangent. At room temperature, the dielectric behaviors of BiFeO 3 ceramics are mainly attributed to the transition of localized charge carriers and the microstructure of grains and grain boundaries. The temperature dependence of dielectric constant and loss tangent confirms that the localized charge carriers are a main contribution to the dielectric permittivity. Activation energy E α of relaxation process for the BiFeO 3 ceramic sintered at 850 °C is 0.397 eV. The obtained BiFeO 3 ceramics show magnetic responses, which are relative to the grain size.