HIGH-RESOLUTION SHORT-RANGE ORDER STUDY OF TELLURITE GLASSES

The short-range atomic order in tellurite glasses containing 2 and 4 mol% P2O5 as a co-glass-former has been investigated by two neutron diffraction techniques. The structure factor, S(Q), was measured up to 350 nm(-1) by the time-of-night method using a pulsed neutron source. Conventional neutron diffraction measurements were carried out on a two-axis diffractometer. An asymmetric maximum, located at 0.195 nm, has been observed in the radial distribution function of the tellurite glass with 2 mol% P2O5. This maximum involves the Te-O pair distribution and the calculated coordination number of the Te atoms is 3.8. Increasing the P2O5 content up to 4 mol% leads to a splitting of the first coordination maximum, with two subpeaks at 0.190 and 0.214 nn. The interpretation of the experimental results was made through a correlation with crystal-like model radial distribution functions.