Compressible spherical dipolar glass model of relaxor ferroelectrics

TL;DR

This paper introduces a compressible spherical dipolar glass model for relaxor ferroelectrics, capturing dielectric and strain interactions, and successfully explains specific heat singularities near critical points, aligning with experimental data.

Contribution

The paper develops a new model incorporating compressibility and anisotropic interactions to better describe relaxor ferroelectrics.

Findings

Model explains anisotropy of anharmonic P4-term

Accurately predicts specific heat singularities

Aligns with calorimetric experimental results

Abstract

The interactions between the dielectric polarization and the fluctuations of the strain (stress) tensor in relaxor ferroelectrics are shown to give rise to the anisotropy of the anharmonic P4-term in the Landau-type free energy, however, the harmonic P2-term is still properly described by the rigid spherical random bond--random field model. These are the essential features of the compressible spherical dipolar glass model, which is used to calculate the singularities of the specific heat near field-induced critical points. The results agree with recent high-resolution calorimetric experiments in PMN [110].