Magnetic anisotropy switching in(Ga,Mn)Aswith increasing hole concentration

K. Hamaya, T. Watanabe, T. Taniyama, A. Oiwa, Y. Kitamoto, Y. Yamazaki
2006 Physical Review B  
We study a possible mechanism of the switching of the magnetic easy axis as a function of hole concentration in (Ga,Mn)As epilayers. In-plane uniaxial magnetic anisotropy along [110] is found to exceed intrinsic cubic magnetocrystalline anisotropy above a hole concentration of p = 1.5 * 10^21 cm^-3 at 4 K. This anisotropy switching can also be realized by post-growth annealing, and the temperature-dependent ac susceptibility is significantly changed with increasing annealing time. On the basis
more » ... f our recent scenario [Phys. Rev. Lett. 94, 147203 (2005); Phys. Rev. B 73, 155204 (2006).], we deduce that the growth of highly hole-concentrated cluster regions with [110] uniaxial anisotropy is likely the predominant cause of the enhancement in [110] uniaxial anisotropy at the high hole concentration regime. We can clearly rule out anisotropic lattice strain as a possible origin of the switching of the magnetic anisotropy.
doi:10.1103/physrevb.74.045201 fatcat:ud7wsozjnvgbjjw3dfjahdeqyu