Electrical properties of the Ag6PSe5X (X = Cl, Br, I) argyrodites

The total electrical conductivities at room temperature of Ag6PSe5Cl, Ag6PSe5Br, and Ag6PSe5I were found to be 2.0 x 10(-1), 5.6 x 10(-1), and 6.8 x 10(-4) S/cm, respectively. In the chloride and iodide compounds, the electronic contribution comprises approximately 1% of the total conductivity, although it exceeds 10% of the total conductivity in the bromide compound. Ag6PSe5CI and Ag6PSe5Br exhibit purely Arrhenius behavior throughout the temperature range 150-300 K. Ag6PSe5I exhibits a second-order anomaly in electrical conductivity at 324 K. (C) 2003 Elsevier Ltd. All rights reserved.