Mn induced modifications of Ga 3d photoemission from (Ga, Mn)As: evidence for long range effects

Using synchrotron based photoemission, we have investigated the Mn-induced changes in Ga 3d core level spectra from as-grown ${\rm Ga}_{1-x}{\rm Mn}_{x}{\rm As}$. Although Mn is located in Ga substitutional sites, and does therefore not have any Ga nearest neighbours, the impact of Mn on the Ga core level spectra is pronounced even at Mn concentrations in the range of 0.5%. The analysis shows that each Mn atom affects a volume corresponding to a sphere with around 1.4 nm diameter.Comment: Submitted to Physical Review B, Brief Repor

Effects of nonuniform Mn distribution in (Ga,Mn)As

Resonant in situ photoemission from Mn 3d states in Ga1-xMnxAs is reported for Mn concentrations down to the very dilute level of 0.1%. Concentration-dependent spectral features are analyzed on the basis of first-principles calculations for systems with selected impurity positions as well as for random alloys. Effects of direct Mn-Mn interaction are found for concentrations as low as 2.5%, and are ascribed to statistical (nonuniform) distribution of Mn atoms