Mn L 3,2 x-ray absorption from (Ga,Mn)As and (Ga,Mn)N

We present Mn L3,2 x-ray absorption measurements from two dilute magnetic semiconductor systems: p-type (Ga,Mn)As, which is ferromagnetic with TC=140 K; and n-type (Ga,Mn)N, in which the magnetic impurities are predominantly paramagnetic. After removing a Mn-rich oxide surface layer by chemical etching, the Mn L3,2 spectra from (Ga,Mn)As appear less localized than in previous reports, which is ascribed to screening due to p–d hybridization. Our results suggest that previous studies may have been influenced by the quality of the surface. In contrast, in the (Ga,Mn)N film the Mn ground state is closer to pure d5.