MECHANICAL AND DIELECTRIC BEHAVIOR OF SOME IONIC GLASSES

Mechanical and electrical relaxation processes are compared on identic al superionic glasses in which the glassy matrix AgPO3 was doped with various kinds of salt dopant. It was found that the same values charac terize the a.c. conductivity as well as the mechanical spectra. Above T approximate to 10K there are two different activated contributions t o the acoustic absorption: one, dominant at high temperatures/low freq uencies is characterized by a linear decrease of the activation energy as the salt dopant is increased; the second, dominant at intermediate temperatures/frequencies is characterized by activation energy values one order of magnitude smaller. At the same time the log-log represen tation of the experimental a.c. conductivity vs. frequency shows a dou ble power law behaviour. Two different relaxing processes can account for the activation energy values and for the double power law behaviou r of the a.c. conductivity.