DISTINGUISHING THE LOCAL ENVIRONMENTS OF Ga AND Ge IN AMORPHOUS (Ga2Se3)(0.25)(GeSe2)(0.75) BY ANOMALOUS X-RAY SCATTERING

Abstract

The amorphous structure of (Ga2Se3)0.25(GeSe2)0.75 is investigated using a combination of anomalous X-ray scattering (AXS) and Reverse-Monte-Carlo (RMC) modeling. It was confirmed that the Ga and Ge atoms can be found exclusively in the tetrahedral configuration. The average coordination number of the Se atoms is found to be 2.34(3) due to the presence of dative bonds. The formation of Ga/Ge-Ga/Ge so-called “wrong bonds” is discussed based on a set of RMC simulations. A strong Ga-Ga second neighbor correlations indicates the formation of Ga-Se clusters within the Ga-Ge-Se glass.