High temperature piezoelectric ceramics based on (1− x)[BiScO3 +Bi(Ni1/2Ti1/2)O3]− xPbTiO3

Abstract: High temperature ferroelectrics are an important aspect of piezoelectric material research for many energy related applications. Some of the desired properties are high Curie temperature, large remanent polarization, and large piezoelectric coefficients. Polycrystalline perovskite ceramics of the composition (1− x)[BiScO3 +Bi(Ni1/2Ti1/2)O3]− xPbTiO3 (BS-BNiT-PT), were synthesized using standard solid state processing. Room temperature X-ray diffraction revealed a perovskite phase with an observed transition from tetragonal to pseudo-cubic symmetry over the compositional range x =0.50–0.60. Compositions rich in PbTiO3 showed strong tetragonal distortions with characteristic first-order phase transitions. As the PbTiO3 content decreased dielectric measurements revealed large permittivities (er′~16,000) with relaxor characteristics up to 400°C. Ferroelectric hysteresis measurements revealed remanent polarizations as high as 31μC/cm2 at x =0.52 with relatively low coercive fields of 25kV/cm. The piezoelectric coefficients, mechanical quality, and planar coupling factors of the x =0.54 composition were 376pC/N, 13.4, and 0.148, respectively. [Copyright &y& Elsevier]