Structure Factor of a Relaxor Ferroelectric

TL;DR

This paper models relaxor ferroelectrics by incorporating dipolar interactions, disorder, and anharmonic forces, providing insights into their correlation functions and structure factors across temperature regimes.

Contribution

It introduces a minimal theoretical model for relaxor ferroelectrics that captures key features of their structure factor and correlation functions, including disorder effects.

Findings

The model reproduces characteristic features of neutron scattering data.

Correlation functions vary with temperature regimes.

Disorder significantly influences the structure factor.

Abstract

We study a minimal model for a relaxor ferroelectric including dipolar interactions, and short-range harmonic and anharmonic forces for the critical modes as in the theory of pure ferroelectrics together with quenched disorder coupled linearly to the critical modes. We present the simplest approximate solution of the model necessary to obtain the principal features of the correlation functions. Specifically, we calculate and compare the structure factor measured by neutron scattering in different characteristic regimes of temperature in the relaxor PbMg$_{1/3}$Nb$_{2/3}$O$_3$.