Amorphous fine powders in the AgI–Ag2PO3.5 system, with 20 to 70mol%AgI, were obtained by using a high-energy ball-milling process. An amorphous sample with the composition, AgI-20mol%Ag2PO3.5, was not obtained by ball-milling. The amorphous sample-forming region accessible by high-energy ball-milling was very similar to the glass-forming region accessible by conventional melt-quenching. The AgI-40mol%Ag2PO3.5 composition, of which an amorphous sample was obtained by ball-milling for 48h, was the most easily-formed amorphous composition in the AgI–Ag2PO3.5 system. The ball-milled samples exhibited high room-temperature ionic conductivities. The σ298 value of the AgI-40mol%Ag2PO3.5 sample changed with ball-milling time. The σ298 value increased steeply with increasing milling time, and attained a maximum of 7.3 x 10−1S/m at about 20h. It was noted that the maximum conductivity was higher than that of melt-quenched glasses having the same composition. The σ298 value of samples which were ball-milled for longer than 30h decreased with increasing milling time, and had a similar value to that of melt-quenched glass.

Mechano-Chemical Synthesis of Amorphous Solids in the System AgI–Ag2PO3.5 and their Silver Ion-Conducting Properties. H.Peng, N.Machida, S.Nishida, T.Shigematsu: Journal of Non-Crystalline Solids, 2003, 318[1-2], 112-20