The bismuth-based perovskite solid solution (100−x)BiScO3−xPbTiO3 (BSPT) was investigated for use at temperatures up to 400°C and above. The high-temperature resistivity, together with dielectric and piezoelectric behaviors of the shear mode for manganese-modified BSPT ceramics near the morphotropic phase boundary composition were studied. The resistivity and time constant were found to be 3×107Ωcm and 0.08s, respectively, at 450°C for modified BSPT66. The dielectric constant Κ11T and dielectric loss were found to be 1112 and 1%, respectively, at room temperature, showing a Curie temperature at 468°C. The electromechanical coupling factor k15 was calculated to be 61%, staying nearly constant up to 440°C, expanding the temperature usage range significantly. The properties indicate that the modified BSPT66 material is a promising candidate for high-temperature shear sensor applications.

No abstract

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 a tetragonal perovskite microstructure at as high as (x = 0.20) 98.1% of TD.

No abstract

No abstract