Anomalous temperature dependence of prepeak in the superionic glass (AgI)(x)(AgPO3)(1-x)

Neutron diffraction studies are reported on the prepeak of the superionic c onducting glass (AgI)(x)(AgPO3)(1-x) as a function of temperature in the gl assy and supercooled-liquid phases. The glass structure consist of regions of amorphous silver phosphate network and of silver iodide. The prepeak ref lects structure in the phosphate network with periodicity d = 10 Angstrom. Its intensity shows anomalous behaviour at a temperature 6-11% above the ca lorimetric glass transition T-g. (C) 2000 Elsevier Science B.V. All rights reserved.