Temperature Dependences of Structural Parameters of PMN in the Region of Diffuse Phase Transition

Abstract

In this work, we analyzed the structural parameters of the lead magnoniobate sample in the temperature range from 20 ºC to 450 ºC by X- ray structural analysis. It was found that the PMN cubic perovskite cell does not undergo distortions over the entire temperature range under study. In the vicinity of a temperature of 250 ºC in PMN, an abrupt decrease in the coefficient of linear expansion from 1.06∙10-5 K-1 to 0.32∙10-5 K-1, which is possibly associated with a change in the anharmonicity of the potential relief of atoms in the structure, is recorded.