X-ray diffraction study of MO-TeO2 (M=Zn and Ba) glasses

Structures of MO-TeO2 (M=Zn and Ba) glasses have been investigated by x-ray diffraction analysis. Local environments around Zn and Ba atoms weve exami ned in terms of the difference RDF curve, Delta RDF, which was obtained by subtracting the RDF curie of ZnO-Teo(2) glass from that of BaO-TeO2 glass a t the same composition. Coordination numbers of Zn and Ba were estimated by the pair function curve fitting with the Delta RDF curves The coordination number of Zn atoms (NZn-O) decreased from 5.3 to 3.9 as ZnO content increa sed from 10 to 40 mol% Coordination numbers of Ba atoms (NBa-O) up to 35 mo l% BaO were 6.1-6.4 independent of BaO content. N-BA (O) decreased over 35 mol% BaO and was 5.6 at 40 mol % BaO On the basis of the local structures a round Zn and Ba atoms revealed in this work and the one around Te atoms der ived from the previous (125) Te static NMR study: the detailed structure mo dels of MO TeO2 (M=Zn and Ba) glasses were proposed.