Abstract: High-energy ball-milling process is a powerful method for the preparation of amorphous phases, nanocrystalline materials, and so on. In this paper, we applied the high-energy ball-milling process
to the synthesis of superionic conducting amorphous materials with Ag₂S content of 80 mol%. Ball milling of 12h to 20h led to the formation of amorphous phases in the composition. The amorphous
samples showed very high ionic conductivities, among which the 20h-ball-milled sample presented the maximum conductivity of 2.96×10⁰Sm^-1 at 298 K. Further ball milling resulted in
partial precipitation of Ag₈SiS₆ crystalline phase, therefore, a decrease in ionic conductivity was observed for the samples ball-milled for longer than 27h. DC polarization measurements suggested
that the ion transport number of the amorphous samples and the ball-milled samples containing some Ag₈SiS₆ crystalline phase, together with that of the Ag₈SiS₆ crystal, was practically unity.

Key words: mechanical milling, amorphous material, silver ion conductivity