Annealing-temperature dependence of the electrical properties of Ba_0.8Pb_0.2TiO₃ as a PTC material

In this research, we investigate how the annealing temperature affects the electrical properties of Ba_0.8Pb_0.2TiO₃ as a positive temperature coefficient material. The material was synthesized via solid-state sintering. The grain size was varied by varying the annealing temperature between 850 °C and 1000 °C for 4 h. Characterization via X-ray diffraction showed that a single-phase compound was formed exhibiting a tetragonal phase. The microstructure was observed using scanning electron microscopy. Average grain size was observed to be between 5 and 10μm. The electrical properties as characterized using impedance spectroscopy showed the presence of grain and grain-boundary contributions in the annealed samples. Dielectric constant and dielectric relaxation phenomenon as a function of annealing temperature have been studied.