X-ray diffraction study on the short-range structure of K2O-TeO2 glasses and melts

The short-range structure of K2O-9TeO(2) and K2O-4TeO(2) in amorphous state s such as glass and melt has been investigated by X-ray diffraction (XRD) a nd semi-empirical molecular orbital calculation (AM1-MOPAC method). The str ucture of amorphous alkali tellurites consisted of the TeO4 trigonal bipyra mids (tbp) and the TeO3 trigonal pyramids (tp). Confirmed in the present wo rk is that the TeO4 trigonal bipyramids characteristics of TeO2-based glass es transform into TeO3 trigonal pyramids with increasing modifier K2O conte nt and a rise of temperature. The usage of XRD and MOPAC enabled us to comp rehend in some details what to happen in phase transition from glasses to m elts, (C) 2000 Elsevier Science S.A. All rights reserved.