Neutron scattering from the superionic glasses, (AgI)(x)(AgPO3)(1-x), through the glass transition

We have performed neutron scattering measurements to study the temperature dependence of the scattering from the superionic glasses (AgI)(x)(AgPO3)(1- x) with x=0.0, 0.3, 0.5 and 0.7 between room temperature and a temperature well above the calorimetric glass transition temperature, T-g. The temperat ure dependence of the positions of the glass/liquid diffraction peaks is fe atureless except in the pure AgPO3 glass where we observe a change in the t emperature derivative of the positions of the first and third peaks at TF. We compare our results with the macroscopic thermal expansion, The peak int ensities show an anomalous decrease on heating that occurs at a temperature about 5-15% higher than T-g. (C) 2000 Elsevier Science B.V. All rights res erved.