Mechano chemical synthesis of a silver ion conductor in the system AgI–Ag3PO4

A high-energy ball-milling process was applied to the preparation of silver ion conductors from the compositions 80AgI·20Ag3PO4 and 60AgI·40Ag3PO4 (mol%); the composition 80AgI·20Ag3PO4 corresponds to that of the crystalline Ag7I4PO4 superionic phase, and the composition 60AgI·40Ag3PO4 is reported as a typical composition of the superionic conducting glasses in this system. For the composition 80AgI·20Ag3PO4, ball milling for longer than 190 h led to the formation of an unknown new crystalline phase, and the new phase showed a high ion conductivity of 6×10−2 S cm−1 at room temperature. The conductivity is higher than that of the crystalline Ag7I4PO4 phase. The ball-milling process for the composition 60AgI⋅40Ag3PO4 made it amorphous, and the ball-milled sample showed a high ion conductivity very similar to that of melt quenched glass with the same chemical composition.