Neutron diffraction study on network structure of As2Se3-Ag2Se glasses andselenium coordination around silver atom

The short range structure analysis of (1 - x)As2Se3-xAg(2)Se (x = 0.05-0.30 ) glasses were studied by the time-of-flight (TOF) neutron diffraction meth od, and the effects of Ag2Se addition on the network structure of AsSe3 tri gonal pyramid were investigated. The As-Se and Se-Se distances of the AsSe3 trigonal pyramids in As2Se3-Ag2S e glasses were at 2.45-2.54 and 3.72-3.85 Angstrom, respectively, and thus the bond angles of angle Se-As-Se for the AsSe3 trigonal pyramids in these glasses were calculated to be about 99.0 degrees. These results indicate th e existence of AsSe3 trigonal pyramid structure in these glasses, but the s hape was not as symmetrical as in crystalline As2Se3. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.