Monte Carlo simulations of magnetovolume instabilities in anti-Invar systems

TL;DR

This paper uses Monte Carlo simulations of a coupled spin-lattice model to replicate magnetovolume effects in anti-Invar systems, revealing a sudden magnetic collapse linked to large volume changes.

Contribution

It introduces a spin-analogous model and Monte Carlo simulations that qualitatively reproduce magnetovolume effects in anti-Invar materials like YMn2.

Findings

Reproduces sudden magnetic moment collapse

Shows large volume change associated with magnetic transition

Demonstrates enhanced thermal expansion in simulations

Abstract

We perform constant pressure Monte Carlo simulations of a spin-analogous model which describes coupled spatial and magnetic degrees of freedom on an fcc lattice. Our calculations qualitatively reproduce magnetovolume effects observed in some rare earth manganese compounds, especially in the anti-Invar material YMn2. These are a sudden collapse of the magnetic moment which is connected with a huge volume change, and a largely enhanced thermal expansion coefficient.