Links between non-180° domain and heterophase structures in ferroelectric solid solutions: from stress relief to phase contents

Abstract

A model of a heterophase sample with interlayers is applied to describe some two-phase states in ferroelectric 0.69BiFe1- x Ga x O3–0.31BaTiO3 solid solutions with x = 0 − 0.06. Features of a coexistence of the rhombohedral and pseudocubic phases are first analysed at variations of a unit-cell parameter of the pseudocubic phase aPC in heterophases with x = const. Conditions for the complete stress relief at planar interfaces hold in the presence of non-180° domains in the rhombohedral phase and at the aforementioned variations of aPC . Agreement between the calculated and experimental results on contents in 0.69BiFe1- x Ga x O3–0.31BaTiO3 at room temperature is achieved.