An anomalous X-ray scattering study on glassy superionic conductor (As2Se3)1-x(CuI)x using a third-generation synchrotron radiation facility

Anomalous X-ray scattering experiments on glassy superionic conductor (As2Se3)(0.4)(CuI)(0.6) were performed at energies close to the As, Se, and Cu K edges using a new detecting system and a third-generation synchrotron radiation facility. The detecting system was composed of a graphite-crystal energy-analyzer and a NaI(TI) detector on a 40-cm-long arm. The overall energy resolution was about 60 eV, which can discriminate the elastic signal from the fluorescence and Compton contributions, and a sufficient number of scattered X-ray photons were acquired within a reasonable data collection time. The differential structure factors, Delta S-i(Q), were obtained from the detailed analyses, indicating that Delta S-As(Q) and Delta S-Se(Q) are similar to those of glassy As2Se3l except at the prepeak position, and Delta S-Cu(Q) that in liquid CuI. From these findings, it can be concluded that a pseudo-binary mixture of the As2Se3 network matrix and CuI-related conduction pathways would be a good structural model for this superionic glass. (c) 2005 Elsevier B.V. All rights reserved.