Characterization of xCuI · (50 - X)AgI · yCu2MoO4 · (50 - y)CuPO3 glasses

Abstract

The xCuI·(50 - x)AgI·yCu2MoO4·(50 - y)CuPO3 glasses with various compositions corresponding to 20 < x < 50 and 15 < y < 37.5 mol % have been prepared by melting the required constituents in an inert atmosphere and quenching in ice cold water. The glass samples are characterized by DSC, AFM, FTIR, XPS, and conductivity techniques. The IR study shows that the main IR bands vs PO- 3, v1PO3- 4, v4 PO3- 4 and v1MoO2- 4 at 1030, 990, 590 and 940 cm-1 change their wave number systematically when CuI is replaced by AgI. XPS results indicate the presence of both Cu+ and Cu2+ and the lowest percentage of Cu+ is 69.7%. XPS results show that the condensed group units like PO- 3 and P2O4- 7 have relatively large change in binding energy when doping salt is introduced. It is believed that it is caused by doping salt distributed in the interstitial positions resulting in phase separation when dopant content is particularly high. A phase separation model has been proposed to illustrate the behaviour of these materials. The source of electronic conductivity in this system is principally from Cu2+ ions existing in host network.