X-ray photoelectron and auger spectroscopy study of copper-sodium-germanate glasses

The role played by copper oxide in reducing the electrical conductivity of copper-sodium-germanate glasses has been investigated by X-ray photoelectron and X-ray excited Auger spectroscopy. Evidence for the presence of copper predominantly in the Cu+ oxidation state has been obtained from the “shake up” satellite structure of the Cu 2p line. The observed Cu LVV Auger line shapes are significantly different in glasses and this indicates a different bonding environment of copper in the glass matrix. The reduction of electrical conductivity with the increase of copper content is explained in terms of cluster formation and to some extent due to the bonding of copper atoms with the glass matrix.