Electrical properties and microstructure of glassy-crystalline Ag+-ion conducting composites synthesized by a high-pressure method

Rigid, mechanically reinforced, composite Ag+-ion conductors based on xAgI·(100-x) (0.67Ag2O·0.33B2O3), 40 ≤ x ≤ 60, glasses and hard insulating powders of α-Al2O3 (2 µm) or ZrO2 (1 µm) were prepared by a high-pressure method. Microstructure of the composites, depended on the content of AgI in the glasses and the temperature of the high-pressure stage of the synthesis. In all cases, however, it consisted of the evenly distributed phases (conductive and insulating), which did not interpenetrate at a nanometer length scale. It was found that the high electrical conductivity of the composites, though somewhat lower than that of the glasses, generally followed the temperature- and composition dependencies of the latter. An important advantage of the composites over the corresponding glasses was their higher microhardness and non-brittleness, which, contrary to the glasses, enabled their post-synthesis machining, cutting or polishing.