STRUCTURE OF TEO2.ZNO GLASSES BY RDF AND TE, ZN K EXAFS

Using synchrotron radiation, structure of TeO2-ZnO glasses with three differ ent ZnO contents (15, 25 and 35 mol%) are investigated by x-ray diffraction, Te K and ZnKEXAFS. X-ray diffraction study suggests the weak Te-O bond at 0.289 nm seen in alpha-TeO2 crystal does not exist i n rite glass structure. Tellurium K EXAFS based on the two shell fitti ng method indicate that interatomic distances between Te and O atoms i n axial sites decreased from 0.208 to 0.199 nm with increasing of ZnO contents, while interatomic distances between Te and O atoms in equato rial sites are the same. Zinc K EXAFS based on the two shell fitting m ethod indicate the existence of the second oxygen shell located at the distance of 0.222-0.228 nm from Zn atom.