Recrystallization effect on mechanical parameters and increasing of Ag+ ionic conductivity in Ag7(Si1-xGex)S5I ceramic materials

This paper presents the preparation and investigation of Ag7(Si1-xGex)S5I (х = 0.2; 0.4; 0.6; 0.8) ceramic materials. Powder patterns of Ag7(Si1-xGex)S5I indicate the formation of a continuous series of solid solutions with the F-43m cubic cell. Ag7(Si1-xGex)S5I ceramic discs with a porosity of 10 ± 1% were obtained by cold pressing followed by annealing at 700°С. Fabricated ceramics were studied by the SEM, EDS, EIS methods and microhardness measurement. The obtained ceramics are characterized by chemical homogeneity and close values of the average crystallite size in the range of 2.52–2.70 μm. Frequency and temperature dependences of electrical conductivity were analyzed by Nyquist plots. The compositional behavior of ionic conductivity is non-linear and is characterized by a conductivity maximum (8.10 × 10−2 S/cm) at x = 0.6. The temperature dependence of the ionic component obeys to Arrhenius law. The influence of the recrystallization process on the electrical parameters of Ag7(Si1-xGex)S5I solid solution microceramics is discussed.