The ratio of interstitial to substitutional site occupation by Mn atoms in GaAs estimated by EXAFS

The location of Mn atoms in the MBE-grown layers of Ga1−xMnxAs is correlated with all important physical properties of the final material, therefore, it is the subject of many studies. It is known that in the as-grown MBE samples the Mn atoms occupy substitutional and interstitial positions but the proportion between these sites is not easy to find. A powerful tool for this kind of study is XAS as it probes the local atomic order and the electronic structure. The EXAFS data analysis was performed considering superposition of possible Mn locations. This allowed for determination of the distribution of Mn between those two lattice sites.