Structure of New Superionic Glasses (CuI) x (AgPO 3 ) 1–x

Abstract

New superionic glasses (CuI)_x(AgPO₃)_1–x with x = 0.1, 0.2 and 0.3 have been prepared by rapid quenching method. Neutron diffraction experiments have been performed by a HIT-II spectrometer at the Neutron Spallation Source, KEK, Japan. A small first diffraction peak at low Q around 0.8 Å was observed in the structure factor for x = 0.2 and x = 0.3, but for x = 0.1 it shows only a shoulder that is similar to the undoped glass AgPO₃. Three new peaks appear at the radial distribution function of (CuI)_x(AgPO₃)_1–x at ∼ 1.9, 2.7 and 3.4 Å, that may correspond to the Cu–O, Cu–I and Cu–Cu pair correlations, respectively. Those peaks increase with the amount of CuI. These results indicate that there are two different kinds of Cu atoms. Cu–I bond in the glass is very similar to that in crystalline α-CuI, and Cu–O bond is very similar to that in Cu₂O insulating crystal.