Magnetic reconfiguration of MnAs/GaAs(001) observed by Magnetic Force Microscopy and Resonant Soft X-ray Scattering

TL;DR

This study explores the temperature-induced magnetic reorientation in MnAs/GaAs(001) films using resonant soft X-ray scattering and magnetic force microscopy, revealing a transition from in-plane to out-of-plane magnetic domains.

Contribution

It provides a detailed analysis of magnetic reorientation mechanisms in MnAs films, combining experimental observations with a simple shape anisotropy model, and confirms the transition at a specific stripe width ratio.

Findings

Magnetic moments reorient from in-plane to out-of-plane with increasing temperature.

The transition occurs when ferromagnetic stripe width is approximately 2.9 times the film thickness.

Experimental results align well with theoretical predictions of stripe width at transition.

Abstract

We investigated the thermal evolution of the magnetic properties of MnAs epitaxial films grown on GaAs(001) during the coexistence of hexagonal/orthorhombic phases using polarized resonant (magnetic) soft X-ray scattering and magnetic force microscopy. The results of the diffuse satellite X-ray peaks were compared to those obtained by magnetic force microscopy and suggest a reorientation of ferromagnetic terraces as temperature rises. By measuring hysteresis loops at these peaks we show that this reorientation is common to all ferromagnetic terraces. The reorientation is explained by a simple model based on the shape anisotropy energy. Demagnetizing factors were calculated for different configurations suggested by the magnetic images. We noted that the magnetic moments flip from an in-plane mono-domain orientation at lower temperatures to a three-domain out-of-plane configuration at higher temperatures. The transition was observed when the ferromagnetic stripe width L is equal to 2.9 times the film thickness d. This is in good agreement with the expected theoretical value of L = 2.6d.