Low-temperature conductivity of composites based on Ag+-ion conducting glasses and α-Al2O3 matrix, prepared via a high-pressure route

Ag+-ion conducting composites based on silver-borate glasses and α-Al2O3 ceramic matrices were synthesized by a high-pressure method (p = 7.7GPa and t = 100-200°C). They exhibited improved mechanical properties (e.g. reduced brittleness). Their electrical conductivity, as well as the conductivity of the corresponding glasses was measured in the wide temperature range from − 190 to + 30°C. It was found out that for all measured samples (composites and glasses) the temperature dependence of the conductivity follows the Arrhenius formula with a single activation energy close to 0.30eV in the whole temperature range. The conductivity of the composites is lower than that of the corresponding glasses by a factor of 5-10, due to percolation phenomena. It was found out that by an appropriate thermal treatment, the conductivity of the composites can be raised to ca 2 · 10− 3S·cm− 1 at room temperature.