It was shown that magnetic structures involving the partial disorder of local magnetic moments on the Mn atoms in (Ga1-xMnx)As lowered the total energy, as compared to the case of perfect ferromagnetic ordering when As defects on the Ga sub-lattice were present. Such magnetic structures were found to be stable for a range of As antisite concentrations, and this accounted for the observed magnetic moments and critical temperatures in (Ga1-xMnx)As. An explanation was proposed for the stabilization of the partially disordered magnetic structures, and it was concluded that the magnetization and critical temperatures should increase substantially upon reducing the number of As antisite defects.

Defect-Induced Magnetic Structure in (Ga1–xMnx)As. P.A.Korzhavyi, I.A.Abrikosov, E.A.Smirnova, L.Bergqvist, P.Mohn, R.Mathieu, P.Svedlindh, J.Sadowski, E.I.Isaev, Y.K.Vekilov, O.Eriksson: Physical Review Letters, 2002, 88[18], 187202 (4pp)