Two-dimensional silver fast-ion conduction in (LaO)AgS

The silver fast-ion conductor (LaO)AgS was examined in temperature-dependen t so impedance and time-of-Right neutron diffraction experiments. Compariso n of our conductivity data with those published earlier suggests that the p resence of unreacted Ag2S resulting From different sample preparation metho ds is the possible reason for severe discrepancies in the conductivity data of other authors. Anisotropic temperature factors obtained by Rietveld ana lysis of our neutron diffraction data indicate enhanced silver ion mobility in the a-b plane of the tetragonal structure. The observed silver ion dens ity shows that the preferred conduction path is via interstitial (1/2 1/2 1 /2) sites, i.e. along < 110 >. (LaO)AgS is a two-dimensional silver fast-io n conductor. (C) 2000 Elsevier Science B.V. All rights reserved.