Structure of new superionic glasses (CuI)_x(AgPO₃)_1-x

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 0.8Å 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 3.4Å, 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.