High Curie temperature perovskite BiInO3-PbTiO3 ceramics

The extent of BiInO₃ substitution in the perovskite system xBiInO₃-(1 - x)PbTiO₃ and the corresponding raise in the Curie temperature were investigated-using thermal analysis, dielectric measurements, x-ray diffraction, and electron microscopy. Maximum tetragonal perovskite distortion (c/a = 1.082) was obtained for x = 0.20, with a corresponding Curie temperature of 582 °C. Phase-pure tetragonal perovskite was obtained for x ≤ 0.25. Compound formation after calcining mixed oxide powders resulted in agglomerated cube-shaped tetragonal perovskite particles, which could be fired to 94.7% of theoretical density (TD). Sol-gel fabrication resulted in nano-sized tetragonal or pseudo-cubic perovskite particles, which after two-step firing, resulted in tetragonal perovskite microstructure at as high as (x = 0.20) 98.1% of TD.