Landau theory description of autferroicity

TL;DR

This paper uses Landau theory to model autferroicity, a type of multiferroic behavior with intrinsic magnetoelectricity, and demonstrates how phase mapping distinguishes it from multiferroics, with first-principles calculations predicting autferroicity in TiGeSe3.

Contribution

It introduces a Landau theory-based model to differentiate autferroics from multiferroics and predicts autferroicity in a specific material using first-principles calculations.

Findings

Landau theory clarifies autferroicity versus multiferroicity.

First-principles calculations predict autferroicity in TiGeSe3.

Phase mapping distinguishes autferroic behavior.

Abstract

Autferroics, recently proposed as a sister branch of multiferroics, exhibit strong intrinsic magnetoelectricity, but ferroelectricity and magnetism are mutually exclusive rather than coexisting. Here, a general model is considered based on the Landau theory, to clarify the distinction between multi and autferroics by qualitative change-rotation in Landau free energy landscape and in particular phase mapping. The TiGeSe$_3$ exemplifies a factual material, whose first-principles computed Landau coefficients predict its autferroicity. Our investigations pave the way for an alternative avenue in the pursuit of intrinsically strong magnetoelectrics.