Structure of Se-Te glasses studied using neutron, X-ray diffraction and reverse Monte Carlo modelling

Pulsed neutron diffraction and synchrotron X-ray diffraction measurements were performed on Se_100-xTe_x bulk glasses with x=10, 20, 30 and 40. The coordination numbers obtained from the diffraction results demonstrate that Se and Te atoms are twofold coordinated and the glass structure is formed by the chain network. The three-dimensional structure model for Se₆₀Te₄₀ glass obtained by using reverse Monte Carlo modelling shows that the alternating arrangements of Se and Te atoms compose the major part of the chain clusters but several other fragments such as Se_n chains and Te-Te dimers are also present in large numbers. The chain clusters have geometrically disordered forms and the interchain atomic order is different from those in the crystal structures of trigonal Se and trigonal Te.