Ag₁₀Te₄Br_3-x Cl_x and Ag ₁₀Te₄Br_3-y i_y: Structural and electrical property tuning of a mixed conductor by partial anion substitution

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 Ag₁₀Te₄Br_3-xCl_x and Ag₁₀Te₄Br_3-yI_y. 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 Ag₁₀Te₄Br_2.8I_0.2 as compared with Ag₁₀Te₄Br₃.