Observation of a temperature dependent asymmetry in the domain structure of a Pd doped FeRh epilayer

TL;DR

This study reveals a temperature-dependent change in magnetic domain symmetry in Pd-doped FeRh epilayers, indicating complex surface and bulk magnetic phase interactions influenced by doping and nanoscale effects.

Contribution

It is the first to demonstrate a temperature-dependent symmetry transition in magnetic domains of Pd-doped FeRh using microscopy analysis.

Findings

Domain symmetry shifts from twofold to mixed at higher temperatures

Surface nematic phase likely influences magnetic behavior

Doping alters the magnetic phase transition characteristics

Abstract

Using X-ray photoelectron emission microscopy we have observed the coexistence of ferromagnetic and antiferromagnetic phases in a (3 at.%)Pd-doped FeRh epilayer. By quantitatively analyzing the resultant images we observe that as the epilayer transforms there is a change in magnetic domain symmetry from predominantly twofold at lower temperatures through to an equally weighted combination of both four and twofold symmetries at higher temperature. It is postulated that the lowered symmetry Ising-like nematic phase resides at the near-surface of the epilayer. This behavior is different to that of undoped FeRh suggesting that the variation in symmetry is driven by the competing structural and electronic interactions in the nanoscale FeRh film coupled with the effect of the chemical doping disorder.