These vacancy defect spinels were studied, with regard to their ion dynamics, by performing alternating-current conductivity measurements between 26.5 and 60GHz; using a vector network analyzer. It was found that the Cu-containing system had a higher plateau frequency than that of the Ag-containing system. An increment in the number of vacancies led to the increase in the plateau frequency of the Cu-containing system. The plateau frequency for the Ag-containing system was less than 26.5GHz.

Y.Ohmuro, T.Ohachi, I.Taniguchi: Solid State Ionics, 1995, 79, 53-9