MBE grown MnGe alloys: An XAS study

The structural properties of Ge:Mn samples grown by MBE in two different ways, namely coevaporated alloys and alloys fabricated from an alternate deposition of Mn and Ge layers, i.e., digital layer alloys (DLA), are compared. The study is based on the X-ray absorption spectroscopy (XAS) in the near edge range (XANES) and in the extended energy range (EXAFS). In particular, an EXAFS analysis shows how much the DLA technique helps to hamper the atomic diffusion of Mn from tetrahedral interstitial sites generally occupied during co-evaporation, and to what extent it is able to reduce the formation of an Mn5Ge3 alloy.