Deviations from the Summerfield scaling in the alternating-current conductivity spectra of single ion conducting glasses were reported for the first time. In contrast to the extensively studied borate and germanate glasses, the conductivity isotherms of alkali tellurite glasses do not superimpose upon application of the Summerfield scaling. The deviations depended upon the alkali oxide content as well as on the type of the alkali ion. Remarkably, the experimental findings differed considerably from theoretical results describing the hopping dynamics of charge carriers in random barrier landscapes.

AC Conductivity Spectra of Alkali Tellurite Glasses - Composition-Dependent Deviations from the Summerfield Scaling. S.Murugavel, B.Roling: Physical Review Letters, 2002, 89[19], 195902 (4pp)