Phase transitions in AgTa_xNb_1−xO₃ solid solutions

Abstract

X-ray diffraction has been used to determine the temperature of phase transitions and the existing distortions of the pseudoperovskite cells throughout the whole range of concentrations of AgTa_xNb_1−xO₃ solid solutions. From the data obtained a phase diagram was constructed. Also plotted were the temperature dependences of the lattice parameters for a few selected concentrations of the solid solutions and also the curve of lattice parameters versus concentration at room temperature. Coexistence of phases was also studied. The existence of a morphotropic region in the concentration range 0.9 < x > 1 was ascertained for the AgTa_xNb_1−xO₃ solution.