A non isothermal phase-field model for the ferromagnetic transition

TL;DR

This paper introduces a non-isothermal phase-field model for ferromagnetic transitions that captures the hysteresis behavior by coupling an order parameter with magnetization dynamics, including paramagnetic and ferromagnetic contributions.

Contribution

It develops a novel phase-field approach that distinguishes between magnetization components and models their evolution across the Curie temperature.

Findings

Reproduces hysteresis effects in uniaxial magnets

Models magnetization dynamics with coupled equations

Accounts for temperature-dependent phase transition behavior

Abstract

We propose a model for non isothermal ferromagnetic phase transition based on a phase field approach, in which the phase parameter is related but not identified with the magnetization. The magnetization is split in a paramagnetic and in a ferromagnetic contribution, dependent on a scalar phase parameter and identically null above the Curie temperature. The dynamics of the magnetization below the Curie temperature is governed by the order parameter evolution equation and by a Landau-Lifshitz type equation for the magnetization vector. In the simple situation of a uniaxial magnet it is shown how the order parameter dynamics reproduces the hysteresis effect of the magnetization.