In-plane spin reorientation transitions in epitaxial Fe(110)/GaAs(110) films

Abstract

Epitaxial Fe films in a thickness range from 4 to 64 monolayers (ML) were grown by molecular beam epitaxy on GaAs(110) at room temperature. The growth was characterized by reflection high energy electron diffraction. The magnetic in-plane anisotropy was investigated by alternating gradient magnetometry in a temperature range from 150 to 295 K. For a 64 ML thick Fe(110) film the [001] axis is the easy axis, the [−110] the intermediate axis, and the hard axis is between [−110] and [−111]. For Fe films with a thickness below 24.2±1.2 ML the [−110] becomes an easy axis at room temperature. A 24 ML Fe film shows a reorientation of the easy axis with decreasing temperature: Above the critical temperature of (251±3) K [−110] is the easy axis, for lower temperatures it becomes an intermediate axis.