Electrical Conductivity, Dielectric, Modulus and Optical Studies of Ag<sub>2</sub>SO<sub>4</sub> and TiO<sub>2</sub> Composite Solid Electrolytes

Abstract

Composite solid electrolytes of the molecular formula (1-x) Ag2SO4 and x TiO2 have been prepared by solid state reaction method. The prepared materials were characterized by various techniques such as X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), thermogravimetric-diffrential thermal analysis (TG-DTA) and scanning electron microscopy (SEM). A sharp increase of conductivity was found in the Arrhenius plot at 693 K due to the β →α phase transition, which is slowed down with the addition of TiO2 particles. The composition x=0.3 shows the maximum conductivity σ = 12.31 S cm-1 at 500 °C. The temperature dependent modulus values involve single type of conduction mechanism over the entire range of temperatures. The optical band gap energy for the pure Ag2SO4 is found to be 4.79 eV, which has decreased with the amount of TiO2 contents because of the defects and changes in local lattice symmetry of the composites.