Ag10Te4Br3-x Clx and Ag 10Te4Br3-y iy: Structural and electrical property tuning of a mixed conductor by partial anion substitution

Abstract

X-ray powder and EDX phase analyses, thermal analyses, impedance spectroscopic measurements, and crystal structure determinations of selected phases are reported to highlight the structural and electric properties of the solid solutions Ag10Te4Br3-xClx and Ag10Te4Br3-yIy. Bromide can be partially substituted by chloride or iodide up to x = 1.6 and y = 0.2, respectively, without changes in the structural properties of the tetramorphic, ion-conducting Ag10Te4Br3. Results from X-ray powder phase analyses have been complemented by data of single crystal structure determinations of selected samples. At r. t. the fully ordered γ-Ag 10Te4Br3 structure type is realized in all chloride containing phases, but a partial iodide substitution leads to the stabilization of the disordered β-Ag10Te4Br 3 structure type. Impedance spectroscopic measurements reveal a significant increase by one order of magnitude of the r. t. silver ion conductivity of Ag10Te4Br2.8I0.2 as compared with Ag10Te4Br3. © 2007 Verlag der Zeitschrift für Naturforschung,.