Effect of clustering on ferromagnetism in (Ga,Mn)As

Mn clustering, hole localization, and the electronic and magnetic properties of Mn clusters were investigated by total energy calculations within the density-functional theory using the projector augmented-wave method. Substitutional Mn on Ga sublattice were treated in different supercell configurations. Delocalized hole states extending throughout the entire supercell were obtained while spin-flip energies for the various Mn units were calculated.