A multicomponent lithium aluminum zinc germanate glass influenced by copper ions in its dielectric and spectroscopic characteristics

Abstract

Multi component Li2O–Al2O3– ZnO–GeO2 glasses doped with CuO ranging from 0 to 1.0 mol% were prepared by the conventional melt quenching technique. Spectroscopic (optical absorption, IR, and EPR) and dielectric properties of the prepared glasses were examined. The EPR and optical absorption studies indicate that low-concentration CuO samples contain both Cu2+ and Cu + ions. CuO concentrations up to 0.6 mol% increased the level of disorder in the glass network, as indicated by IR studies. The dielectric study reveals the influence of copper valance states on the structural aspect of the samples. It has been shown from all these studies that the copper ions can be present in Cu3+ state in these glasses as well as Cu2+ and Cu+ states and thus participate in glass network formation. A quantitative analysis of the dielectric properties of the glasses has indicated that when the CuO concentration exceeds 0.6 mol%, the insulating strength increases. As a result, aluminum ions have been found to be tetrahedrally coordinated instead of octahedral. CuO concentrations above 0.6 mol% in the glass matrix significantly alter the physical properties of these glasses. The reduction of Cu2+ ions to Cu + ions has significantly effected the spectroscopic and dielectric investigations.