Out-of-plane magnetization reversal processes of (Ga,Mn)As with two different hole concentrations

TL;DR

This study investigates how different hole concentrations in (Ga,Mn)As epilayers influence out-of-plane magnetization reversal processes, revealing distinct behaviors during magnetization rotation but similar switching mechanisms.

Contribution

It provides new insights into the role of hole concentration in magnetization processes of (Ga,Mn)As, linking anisotropy balance to reversal behaviors.

Findings

Different magnetization rotation behaviors depending on hole concentration.

Switching from in-plane to out-of-plane occurs via domain wall propagation, independent of hole concentration.

Balance of cubic and uniaxial anisotropies explains the observed differences.

Abstract

We study magnetization reversal processes of in-plane magnetized (Ga,Mn)As epilayers with different hole concentrations in out-of-plane magnetic fields using magnetotransport measurements. A clear difference in the magnetization process is found in two separate samples with hole concentrations of 10^20 cm^-3 and 10^21 cm^-3 as the magnetization rotates from the out-of-plane saturation to the in-plane remanence. Magnetization switching process from the in-plane remanence to the out-of-plane direction, on the other hand, shows no hole concentration dependence, where the switching process occurs via domain wall propagation. We show that the balance of <100> cubic magnetocrystalline anisotropy and uniaxial [110] anisotropy gives an understanding of the difference in the out-of-plane magnetization processes of (Ga,Mn)As epilayers.