X-ray absorption study of the electronic structure of Mn-doped amorphous Si

Abstract

The electronic structure of Mn in amorphous Si (a-MnxSi1−x) is studied by x-ray absorption spectroscopy at the Mn L3,2 edges for x=0.005−0.18. Except for the x=0.005 sample, which shows a slight signature of Mn2+ atomic multiplets associated with a local Mn moment, all samples have broad and featureless L3,2 absorption peaks, corresponding to an itinerant state for all 3d electrons. The broad x-ray absorption spectra exclude the possibility of a localized 3d moment and explain the unexpectedly quenched Mn moment in this magnetically doped amorphous semiconductor. Such a fully delocalized d state of Mn dopant in Si has not been previously suggested.