Magnetic moment of Mn in the ferromagnetic semiconductor (Ga0.98Mn0.02)As

We have studied the quasibinary ferromagnetic semiconductor (Ga0.98Mn0.02)A s by magnetic circular dichroism in x-ray absorption. We find a richly stru ctured Mn absorption spectrum typical for localized 3d electrons. An analys is of the magnetization-averaged and dichroism line shapes shows a local Mn moment of 4.6 mu(B), which is close to the Hund's rule moment for the half -filled 3d shell. The magnitude of the dichroism reveals that only about 1/ 7 of the Mn atoms participate in the ferromagnetic order. Our experiment do es not show a distinction between the ferro- and paramagnetic Mn atoms. (C) 2000 American Institute of Physics. [S0003-6951(00)00720-8].