Tailoring the magnetism of GaMnAs films by ion irradiation

TL;DR

This study demonstrates that ion irradiation can effectively modify the magnetic properties of GaMnAs films by controlling hole concentration, leading to significant changes in coercivity, magnetization, and Curie temperature.

Contribution

It introduces a method to tailor GaMnAs film magnetism through He ion irradiation, providing a controllable way to adjust magnetic properties.

Findings

Coercivity increased by over three times

Magnetization and Curie temperature decreased with fluence

Magnetism tuning linked to hole compensation by defects

Abstract

Ion irradiation of semiconductors is a well understood method to tune the carrier concentration in a controlled manner. We show that the ferromagnetism in GaMnAs films, known to be hole-mediated, can be modified by He ion irradiation. The coercivity can be increased by more than three times. The magnetization, Curie temperature and the saturation field along the out-of-plane hard axis all decrease as the fluence increases. The electrical and structural characterization of the irradiated GaMnAs layers indicates that the controlled tailoring of magnetism results from a compensation of holes by generated electrical defects.