FERROMAGNETISM AND ITS STABILITY IN THE DILUTED MAGNETIC SEMICONDUCTOR (IN,MN)AS

Carrier-induced ferromagnetism in the doped diluted magnetic semicondu ctors (In,Mn up arrow,Mn down arrow, A)As, where A is As or Sn and Mn up arrow (Mn down arrow) denotes Mn atoms whose local magnetic moment is parallel (antiparallel) to the magnetization, are investigated usin g the Korringa-Kohn-Rostoker coherent-potential approximation and loca l density approximation first-principles calculation. The result shows that (i) the ferromagnetic state is stable due to the double exchange at low concentrations of A,and (ii) a spin-glass-like local-moment di sordered state, which stems from the superexchange, is more favorable when the Mn d holes are nearly compensated.