Distribution of magnetic domain pinning fields in GaMnAs ferromagnetic films

TL;DR

This study investigates the distribution of magnetic domain pinning fields in GaMnAs ferromagnetic films using the planar Hall effect, revealing significant differences between as-grown and annealed samples related to magnetic anisotropy.

Contribution

It introduces a method to determine pinning field distributions in GaMnAs films and compares the effects of annealing on magnetic anisotropy and domain pinning.

Findings

As-grown films have narrower pinning field distributions than annealed films.

Annealing affects the magnetic anisotropy non-uniformity in GaMnAs.

The study enhances understanding of magnetic domain landscapes in ferromagnetic semiconductors.

Abstract

Using the angular dependence of the planar Hall effect in GaMnAs ferromagnetic films, we were able to determine the distribution of magnetic domain pinning fields in this material. Interestingly, there is a major difference between the pinning field distribution in as-grown and in annealed films, the former showing a strikingly narrower distribution than the latter. This conspicuous difference can be attributed to the degree of non-uniformity of magnetic anisotropy in both types of films. This finding provides a better understanding of the magnetic domain landscape in GaMnAs that has been the subject of intense debate.