Microstructural characteristics and nonequilibrium core-shell phase in (PbxSr1-x)TiO3 materials and their electrical properties

Microstructural characteristics and the corresponding resistivity-temperatu re (rho-T) properties of microwave- and conventionalsintered Pb0.6Sr0.4TiO3 materials with positive temperature coefficient of resistivity (PTCR) were investigated in the present work. The specimens prepared by microwave sint ering exhibited a single T-c, whereas those prepared using conventional sin tering show double T-c behavior. During the microstructural investigations, sintering aids, SiO2 and TiO2, showed intriguing liquid phase sintering ch aracteristics in the specimens. Large amounts of Pb-species dissolved in hi gh Si regions, where a nonequilibrium core-shell structure was frequently o bserved, especially for microwave sintered specimens, which showed very com plicated domain arrangements in the gain interiors.