Atomic ordering in xGa 2O 3·(100 − x)TeO 2 glasses ( x=10, 17.5, 25) by X-ray diffraction

Abstract

Atomic distribution functions for xGa 2O 3·(100 − x)TeO 2 glasses ( x=10, 17.5, 25) have been obtained from diffraction experiments employing a synchrotron radiation source. First neighbour atomic distances and coordination numbers in the glasses investigated have been determined by decomposing the experimental atomic distribution functions into a set of Gaussians each pertaining to a particular type of atomic pairs. It has been found that xGa 2O 3·(100 − x)TeO 2 glasses ( x=10, 17.5, 25) may well be described as an assembly of tetrahedral GaO 4 units uniformly embedded into a matrix of more (TeO 3+1) or less distorted (TeO 4) trigonal bipyramids where each Te in a perfect TeO 4 bipyramid is surrounded by four oxygens distributed over equatorial and axial positions and each Te in a distorted TeO 3+1 bipyramid has one of its axial Te–O bonds considerably elongated.