THE STRUCTURE OF AG-BORATE AND LI-BORATE GLASSES OF THE COMPOSITION (AG2O.2B2O3)1-X(AGI)X AND (LI2O.2B2O3)

In both Li- and Ag-diborate glasses, the interpenetrating systems of diborate chains characteristic of the crystalline structure are completely destroyed. The Li-diborate glass is a disordered mixture of all possible borate-like configurations characterized by an ordering distance of about 4.5 angstrom for trigonal and of about 4 angstrom for tetrahedral borate units. In the Ag-diborate glass, the main features of the neutron scattering diagram can be simulated for small amounts of AgI (x = 0.1) by an ordering of diborate units (cages) at a separation of 6.7 angstrom. For a greater amount of AgI (x = 0.6), an appropriate number of diborate units have a separation of about 8.8 angstrom and the AgI phase forms clusters with a maximum diameter of about 8 angstrom.