Synthesis and characterization of Cu2O·TeO2 and CuI·Cu2O·TeO2 glasses

Cu2O·TeO2 and CuI·Cu2O·TeO2 glasses were synthesized and characterized by complex impedance measurement, Raman spectroscopy, X-ray photoelectron spectroscopy, and atomic force microscopy techniques. Samples of the binary and the ternary systems are found to have both Cu+ and Cu2+ with their relative concentration being composition dependent. Bonds like -O-Cu2+-O-, leading to the formation of bridging oxygen are found to form in the binary system. Structural units like (Te3O84−)n are also found to form when Cu2O content is high in the binary system. Phase separation is observed in the ternary system. The glass structure and hence the ionic conduction behavior are found to depend upon chemical composition. When CuI content exceeds 60 mol%, the crystalline phase of α-Cul gets stabilized at room temperature, thus causing the enhancement in conductivity.