Local structure and chemical valency of Mn impurities in wide-band-gap III–V magnetic alloy semiconductors Ga1−xMnxN

Local structure and effective chemical valency of Mn impurity atoms incorporated in wide-band-gap (Ga,Mn)N epilayers have been investigated by using x-ray absorption fine structure techniques. The x-ray results provide direct evidence for the substitution of majority Mn atoms for the Ga sites in GaN, with an effective valency close to Mn(II), up to a rather high Mn concentration about 2 at. %. A small fraction of the impurity atoms could also form Mn clusters.