Partial structure analysis of amorphous Ge15Te80M5 (M=Cu, Ag and In)

Abstract All partial structures of Ge15Te80M5 (M=Cu, Ag and In) have been studied using extended X-ray absorption fine structure. The coordination numbers (CN) around Cu and Ag atoms are smaller than four, which is expected from a rigid percolation model. The CN around In atoms is 3.4. This different CN for the metal atoms is attributed to the difference of the chemical bonds between M and Te. Two models in which the local order of Ge is 4-fold and Te atoms bridge two GeTe4 tetrahedra are supported.