STRUCTURAL STUDIES ON SUPERIONIC GLASS AGI-AG2O-MOO3

Superionic conducting glass of the mole percent 60% Ag I-20% Ag2 O-20% MoO3 was prepared by rapid quenching from the melt. EXAFS and X-ray RDF studies in dicate the presence of strong Ag-I interactions with rAg-1=2.87 Å. Two Ag-O interac tions whose distances differ by 0.38 Å are also indicated. X-Ray RDF studies also yield rMo-O=2.1 Å and the coordination number of oxygen around Mo, nMo-O=5.7. A model is proposed which consists of a three dimensional network of distorted MoO6 octahedra, which are 6, 4, and 2-corner shared leading to large channels in the structure. The Ag+ ions form bonds and secondary interactions with both non-bridging and bridging oxygen atoms in the network. The I- ions surround the Ag+ ions in the voids created by the glass network. The results show that Ag+ and I- ions are highly dispersed in the glass network and cluster formation was not found as proposed by earlier workers. © 1990, THE PHYSICAL SOCIETY OF JAPAN. All rights reserved.