Correlation between conductivity and free volume in rubidium and cesium silicate glasses

Abstract

It is shown that conductivity and molar volume in binary rubidium and cesium silicate glasses, both measured at room temperature, obey a common cubic scaling relation due to increase in alkali content. The drastic drop in conductivity up to 15 orders of magnitude for so many ion-conducting binary alkali silicate glasses (in wide composition range) is mainly caused by the structure and the ion content. In particular, it is suggested that the glass network expansion, which is related to the available free volume, is a parameter that could explain the increase in ionic conductivity for these binary systems.

Synthesis, thermal stability and the effects of ion irradiation in amorphous Si–O–C alloys

“…In some instances (provided enough resolution), these phases can be distinguished as separate peaks [28], in other cases a deconvolution of a broad peak (a few eV's wide) has been attempted [23,29]. None of these two results were observed here.…”

“…In analogy, the changes in binding energy of the core level feature due to charging effects may be due to a decrease in free volume of the amorphous alloys. In fact several studies have been done that relate the conductivity of a glass to the free volume [28]. Since the deposition of the Si-O-C alloy was carried out at room temperature, uncompensated bonding (or weak bonding) are likely to form, as the amplitudes of the atomic vibrations are somehow limited at such temperature.…”