Sintering temperature influence on phase stability in barium titanate ceramics with very small grain size

Abstract
Starting from a barium titanate powder of 0.07 μm grain size and a coherently diffracting domain size of 0.017 μm, several pellets were prepared and later sintered at different temperatures. Dielectric constant measurements have shown that between - 150 and 175 °C the green sample stable phase is cubic. The tetragonal-cubic and rhombohedral-orthorhombic transitions appear when the sample is sintered at 700 and 900°C respectively. A non-equilibrium anomaly has been found at °C when cooling and at 35°C when heating the green sample at a low rate.