Electric field assisted copper diffusion in soda-lime glass: a study of ion migration, activation energy and ion interactions

Abstract

We carry out electric field assisted diffusion of copper ions from metal electrodes into soda-lime glass and demonstrate diffusion at a lower temperature than thermal diffusion. We demonstrate the formation of a spontaneous potential difference when the glass is reheated between non-contacting electrodes, and show how this technique, termed Thermal Relaxation Ion Electro-Spectroscopy, when combined with energy dispersive analysis in scanning electron microscopy can be used to understand aspects of the diffusion process. We find strong interactions between copper and the other ions in glass that cause local concentration maxima in these ions. Thermal annealing of copper diffused glass leads to a uniform concentration of copper that may be useful for device applications. Copper ions obey the same Meyer-Neldel rule as other metals when diffusing in glass.