Fast ion transport in the new mixed system (CuI)x·[(Ag2O)2·(V2O5)]100−x (40≤x≤80)

Abstract

The new mixed system (Cul)x·[(Ag2O)2·V2O5)]100−x where x=40, 45, 50, 55, 60, 65, 70, 75 and 80 mol% was investigated as a possible glassy fast ion conductor by preparing molten mixtures and quenching them to low temperatures. The analysis of their composition was carried out using differential scanning calorimetry (DSC) and powder X-ray diffraction (XRD) techniques. These studies have confirmed the formation of new substances. Formation of AgI in some samples was also revealed by XRD analysis and by the occurrence of a characteristic β → α phase transition temperature around 420 K identified through DSC experiments as well. Detailed temperature-dependent a.c. electrical conductivity studies were carried out on the new materials by a.c. impedance analysis in the frequency range 65.5 kHz-1 Hz and over the temperature range 293 to 398 K. It has been found that the highest electrical conductivity of 3.64×10−3 S cm−1 at 305 K due to the migration of Ag+ ions and the lowest activation energy of 0.1 eV in the above temperature range of investigation could be realized for the composition 40CuI-40Ag2O-20V2O5 in the mixed system.