SB L(III)-EDGE XAS STUDY OF THE TERNARY-SYSTEM SB2S3-AS2S3-TL2S

The local environment of antimony atoms in glassy samples of the syste m Sb2S3-As2S3-Tl2S is studied by X-ray absorption spectroscopy at the Sb L(III)-edge. The crystalline compound TlSb3S5, situated within the zone of glass formation of the Sb2S3-As2S3-Tl2S phase diagram, is used as reference compound in order to derive appropriate phase and amplit ude functions for the extended X-ray absorption fine structure (EXAFS) study. The limits of EXAFS in studying the local order around antimon y in compounds with complex structure are discussed. The possibilities of a combined application of EXAFS, X-ray absorption near edge struct ure and Sb-121 Mossbauer spectroscopy to the study of these compounds are shown. The results are discussed in terms of a model of random sub stitution of arsenic by antimony.