Recrystallization and heterovalent substitution effects on mechanical and electrical parameters of Ag6+x(P1−xGex)S5I–based ceramics

Abstract

Herein, we present the results of a study of nanopowders of Ag6.25P0.75Ge0.25S5I, Ag6.5P0.5Ge0.5S5I solid solutions, and ceramic materials based on them. Nanopowders were obtained by dry grinding in a ball mill and characterized by XRD and SEM. Solid solutions based ceramic materials obtained by annealing of pressed disks were studied by SEM, EDS, EIS, and microhardness measurement. The SEM method revealed a change in the size of crystallites during recrystallization. The frequency dependence of the electrical conductivity is typical for superionic conductors. For ceramics of the composition Ag6.5P0.5Ge0.5S5I, a slight increase in ionic electrical conductivity of 3.62 × 10–2 S/cm (30 min) and 3.84 × 10–2 S/cm (60 min) is observed with a decrease in crystallite size. For the entire series of solid solutions of Ag6+x(P1−xGex)S5I, a comparative analysis of the parameters of ceramics made from micro- and nanocrystalline powders (with different grain sizes) with single crystalline samples was performed.