Electrical conduction in glass fibres subjected to a sodium to or from silver ion-exchange treatment

Abstract

Both DC and AC resistivities of some silicate glass fibres containing 10 to 30 mol.% sodium and subjected to a sodium to or from silver ion-exchange treatment have been investigated. Ion-exchanged fibres exhibit resistivity and activation energy values lower than those of the untreated ones. A suitable combination of temperature and electric field brings about a further semi-permanent reduction in resistivity and activation energy values. Typical values of room temperature resistivity and activation energy in this high conducting state are approximately 50 Ω cm and 0.04 eV respectively. Such behaviour is explained on the basis of formation of an interconnected silver-rich phase under the combined influence of temperature and a suitable electric field. The properties exhibited by these materials are comparable to some of the conventional fast ion conducting glasses containing a higher silver concentration than those in the present system.