Local electronic structure of the tellurium atoms in As2Te3-GeTe compounds

The local electronic structure of tellurium atoms in As2Te3-GeTe crystallin e compounds is experimentally studied by the combined use of X-ray photoele ctron spectroscopy (XPS), X-ray absorption spectroscopy (XAS) and Te-125 Mo ssbauer spectroscopy. From As2Te3 to GeTe it is found that: (i) the Te 3d(5 /2) core-level binding energy measured by XPS decreases; (ii) the energy of the main XAS peak observed at the Te L-I edge increases and the XAS peak b roadens; and (iii) the Te-125 Mossbauer quadrupole splitting decreases. The se observed variations are explained from the influence of the two very dif ferent Te local environments found in the As2Te3-GeTe compounds. (C) 1999 E lsevier Science Ltd. All rights reserved.