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B Roling

Publications and source records attributed to B Roling.

4 recordsLinked to original sources
PubMed2002

ac conductivity spectra of alkali tellurite glasses: composition-dependent deviations from the Summerfield scaling.

We report, for the first time, deviations from the Summerfield scaling in the ac conductivity spectra of single ion conducting glasses. 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 depend on the alkali oxide content as well as on the type of the alkali ion. Remarkably, our experimental findings differ considerably from theoretical results describing the hopping dynamics of charge carriers in random barrier landscapes.

Journal Article↗
PubMed2001

Ionic conduction in glass: new information on the interrelation between the "Jonscher behavior" and the "nearly constant-loss behavior" from broadband conductivity spectra.

We analyze broadband ac conductivity spectra of various ion conducting glasses with regard to the composition dependence of the "Jonscher behavior" and of the "nearly constant-loss behavior." In the temperature range of our experiments (173 K< or =T< or =573 K), both types of behavior are closely related, indicating that both arise from ion hopping. However, the "nearly constant-loss behavior" observed at temperatures below 100 K seems to be caused by other dynamic processes.

Journal Article↗
PubMed2000

Nonuniversal features of the ac conductivity in ion conducting glasses

Recently, Sidebottom [Phys. Rev. Lett. 82, 3653 (1999)] proposed a new scaling approach for the conductivity spectra of ion conducting glasses. This approach is based on the condition that the shape of the spectra is universal. In this Letter, we show that this condition is generally not fulfilled, but that the shape depends on the glass composition. In single alkali glasses, the frequency dependence of the conductivity varies with the alkali oxide content. Furthermore, the mixing of dissimilar alkali ions leads to pronounced changes in the shape of the conductivity spectra.

Journal Article↗