Structure of lanthanum-tellurite glass-ceramics: A neutron diffraction study

The structure of Lanthanum-Telluride glass/glass-ceramic systems has been studied using neutron diffraction technique. Analysis of diffraction data is done by using MCGR method. The short range order and co-ordination number distribution has been successfully determined. We show that these systems have TeO4 bi-pyramidal, TeO3 trigonal pyramid and LaO6 polyhedral units as short range order. The number of TeO3 structural units increases, thus decreasing the average Te co-ordination number, for glass-ceramics of higher La2O3 concentration. The La-O peak also gets sharper with increase in La2O3 content. Differential Thermal Analysis (DTA) has been performed to measure glass transition and crystallization temperatures.