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

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