Models for the description of uniaxially modulated materials

TL;DR

This paper reviews symmetry-based models, especially pseudo spin models, for describing uniaxially modulated materials, focusing on their formulation, statistical mechanics, and connection to experimental data.

Contribution

It introduces a comprehensive symmetry-based framework for modeling structurally modulated materials using local variables and pseudo spin models.

Findings

Framework enables explicit modeling of modulated structures.

Methods for translating models to experimental predictions.

Approaches for assessing defect influences.

Abstract

Models which allow an explicit application to structurally modulated substances are reviewed within the frame of a symmetry-based approach starting from discrete lattice theory. Focus is set on models formulated in terms of local variables assigned to discrete crystallographic units (unit cells or parts of them). Especially considered are symmetry-based pseudo spin models. Methods are discussed which permit the handling of the statistical mechanics of such models, the translation of model calculation results to a form allowing the prediction of experimental data, and the theoretical determination of point defect influences.