A dielectric and ferroelectric solid solution of (1 − x)BaSnO3–xPbTiO3 with morphotropic phase boundary

Abstract

New solid solutions (1 − x)BaSnO₃–xPbTiO₃ [(1 − x)BSn–xPT] have been synthesized in the form of ceramics by a solid state reaction method and characterized by means of X-ray diffraction, dielectric spectroscopy, piezoelectric and ferroelectric measurements. A partial solid state phase diagram of the binary system is established. It exhibits a morphotropic phase boundary region in the composition range between x = 0.61 and 0.65. The ceramics of 0.50BaSnO₃–0.50PbTiO₃ show typical relaxor ferroelectric behavior, with the diffuse maximum of high permittivity shifting to higher temperature upon increasing frequency. With further increase of the PT content, the permittivity peaks become sharper and frequency-independent, indicating a ferroelectric phase transition, the temperature of which (T_C) increases with x. Thus, the transformation from a relaxor to a ferroelectric phase has been demonstrated in this solid solution system.