Evidence of anomalous intermediate-range ordering in superionic borate glasses from neutron diffraction.

Abstract

Evidence of intermediate-range ordering in a superionic (AgI)x(${\mathrm{Ag}}_{2}$O+2${\mathrm{B}}_{2}$${\mathrm{O}}_{3}$${)}_{1\mathrm{\ensuremath{-}}\mathit{x}}$ glass is presented. Comparative neutron-diffraction measurements were performed in a low (x=0.1) and a high (x=0.6) -AgI-concentration glass. A strong and sharp diffraction peak at an anomalously low Q value of 0.8 A${\r{}}^{\mathrm{\ensuremath{-}}1}$ is observed for the x=0.6 glass, which is not present in the x=0.1 glass. The phenomenon is attributed to an ordering of the intermediate-range structure, due either to formations of AgI clusters or to density deficits in the boron-oxygen network.