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

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.