Abstract
The effects of various liquid-phase sintering aids on (Pb 0.6 Sr 0.4 )TiO 3 ceramics have been investigated. The relationships between electrical properties and microstructures have been scrutinized. It has been found that, among the sintering aids studied, only SiO 2 exhibits a significant effect on the grain growth of (Pb 0.6 Sr 0.4 )TiO 3 . The optimum firing profiles for sound microstructure and good electrical properties of (Pb 0.6 Sr 0.4 )TiO 3 +5.0 mol% SiO 2 have been established. The V-shaped electrical behavior is prominent, and a PTCR jump of about 10 2.9 is observed. The formation of cation vacancies may increase the resistivity of the over-fired specimens. Various milling methods to pulverize the calcined powder and the optimum amount of packing protection powder during sintering are also discussed.