Neutron scattering and thermal measurements on the superionic-conducting Ag2S–AgPO3 glass system

Superionic-conducting glasses (Ag2S)x(AgPO3)1−x with x=0.1, 0.2, 0.3, 0.5, 0.7, 0.8 and 0.9 have been prepared by rapid quenching methods, although for x=0.8 and 0.9 they also contain crystalline Ag2S. We report DTA measurements of the thermodynamic glass transition temperature, Tg, and neutron diffraction data taken as a function of temperature through Tg. The neutron measurements show no prepeak at any composition or temperature, indicating that there is no clustering, in contrast with the AgI–AgPO3 system where clustering is found with a length scale of order 10 A [1]. Both systems form superionic-conducting glasses, showing that clustering is not essential for such conductivity.