Fast ion conduction in lithia-containing glasses after ion exchange

Abstract

High electrical conductivity has been induced in silicate glasses containing Li₂O after subjecting them to a lithium/silver ion exchange treatment followed by a suitable combination of temperature and electric field. The room-temperature resistivities of these switched samples range from 50 Ω cm to 1000 Ω cm. The activation energy for conduction has values in the range 0.01 to 0.16 eV. The critical electric field for switching is found to be of the order of a few volts per centimetre. The field-induced switching is explained on the basis of growth of a silver-rich phase to the percolation configuration. Wagner's asymmetric polarisation cell measurements show that the charge carriers are ionic in the glasses in their highly conducting states.