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

Abstract The short-range structure of K 2 O–9TeO 2 and K 2 O–4TeO 2 in amorphous states such as glass and melt has been investigated by X-ray diffraction (XRD) and semi-empirical molecular orbital calculation (AM1-MOPAC method). The structure of amorphous alkali tellurites consisted of the TeO 4 trigonal bipyramids (tbp) and the TeO 3 trigonal pyramids (tp). Confirmed in the present work is that the TeO 4 trigonal bipyramids characteristics of TeO 2 -based glasses transform into TeO 3 trigonal pyramids with increasing modifier K 2 O content and a rise of temperature. The usage of XRD and MOPAC enabled us to comprehend in some details what to happen in phase transition from glasses to melts.