Calcium Bismuth Titanate with High Curie Temperature (Tc) for High-Temperature Sensor Applications

Bismuth layer-structured ferroelectric (BLSF) ceramics exhibit linearity in resistivity with respect to temperature changes, and therefore find application as high-temperature sensor materials. In this study, calcium bismuth titanate (CBT), a BLSF material, was synthesized by calcining combined oxide precursors at 850 degrees C for 2 h, and its particle size distribution, phase analysis, grain size distribution and morphology were characterized. Circular discs were prepared by sintering in the temperature range of 1000 to 1200 degrees C. The sintered discs were characterized for dielectric constant (K), P-E hysteresis loop and DC electrical resistivity (rho) from 100 to 900 degrees C. The highest density (> 95% Th.) was obtained for samples sintered at 1175 degrees C. DC resistivity decreased linearly from 10(14) to 10(5) ohm cm with the rise in temperature from 100 to 900 degrees C, therefore confirming CBT as a prospective high-temperature sensor material.