Kinetics of first order magnetostructural transition in single crystalline FeRh thin film

Abstract

The FeRh alloy has been the subject of many experimental and theoretical studies over the last fifty years.[1-3] This interest is primarily due to the observation that the near-equiatomic phase of FeRh possesses a chemically ordered CsCl-type structure which exhibits an abrupt antiferromagnetic (AFM) to ferromagnetic (FM) transition with heating to a transition temperature of around 350K in the bulk and thin film forms. [1-3]. Previous researches show that the first order magnetostructural transition in ordered FeRh-based alloys is very sensitive to composition, temperature, external magnetic field and pressure [2-4]. This AFM-FM transition thus provides an interesting case to understand the nucleation and growth kinetics across a first order phase transition. Although many attempts have been made in order to clarify the underlying mechanism of this magnetostructural transition, the local origin responsible for the nucleation and growth of both FM and AFM phases and the coexistence of the two phases expected from a first-order transition is still under debate for this system. In addition, the nucleation and growth processes of both FM and AFM phases are crucial to the proposed applications. Previously, we have studied the magnetostructural phase transition behavior of polycrystalline FeRh thin films [5]. In this work, we report the temperature and time dependent magnetization of FM phase in epitaxial FeRh thin films across the AFM-FM transition on both heating and cooling process by vibrating sample magnetometer.