Crystal Structure and Ionic Conduction Mechanism of AgHgSX (X = Br, I)

Abstract

Abstract New Ag+ ionic conductors AgHgSX (X = Br, I) were synthesized by solid-state reactions of AgX (X = Br, I) and HgS. AgHgSI shows a phase transition at 578 K. The crystal structure of the high temperature phase has been determined to be P212121 (No. 19) by the Rietveld refinement using the powder X-ray diffraction pattern. The electric conductivity at 500 K measured by the AC impedance method was 2.6 × 10−4 S cm−1 for the high temperature phase of AgHgSI, 1.2 × 10−4 S cm−1 for the low temperature phase of AgHgSI, and 1.1 × 10−4 S cm−1 for AgHgSBr. The charge density analysis of the AgHgSX (X = Br, I) clearly showed the Ag+ ionic conduction path when analyzed by the Maximum Entropy Method (MEM) combined with Rietveld analysis.