Semiconducting Barium Titanate Ceramics Prepared by Boron‐Containing Liquid‐Phase Sintering

Semiconducting BaTiO 3 ceramics have been prepared by adding BN as a sintering aid. Density as high as 93% of theoretical and grain size as large as 16 μm are obtained after sintering at 1160°C. Most significant is that the semiconducting BaTiO 3 is obtained at sintering temperatures as low as 1100°C. The low‐temperature‐sintered BaTiO 3 exhibits a positive temperature coefficient. (PTC) anomaly above 120°C with a resistivity maximum at a temperature as high as 400°C, which is much higher than that of the conventional BaTiO 3 . The incorporation of B into the perovskite structure is negligible. Also, the presence of B at a grain boundary after sintering is believed to enhance the PTC effect.