CORRELATION BETWEEN MECHANICAL AND ELECTRICAL LOSSES IN TRANSITION-METAL OXIDE GLASSES

The internal friction in iron phosphate glasses containing various glass modifiers has been studied in the temperature range from 120 to 700 K. The low frequency torsion pendulum technique has been employed. The dielectric loss has been investigated by two independent methods: the absorption current method and with an a.c. transformer bridge. The internal friction spectra exhibit a low temperature peak that can be related to the electron transfer between iron atoms in different valence states. It is confirmed that the dielectric loss peak and d.c. conductivity reveal a similar activation energy to the internal friction peak. The obtained data have been interpreted in the framework of a new model of relaxation in glasses recently proposed by Hunt.