Electronic microscopic, thermal and electrical properties of Bi ₂V_1-xTi_xO_5.5-δ (0.05≤x≤0.20) oxide ion conductors

In the present study, the effect of titanium substitution for vanadium on oxide ion conductivity, phase stability and thermal expansion has been investigated. The exact solid solubility limit of the dopant and its effect on conductivity as well as thermal expansion, have been studied. The samples have been prepared by conventional solid-state technique. The sintered samples were characterized using differential thermal analysis (DTA), thermo-gravimetric analysis (TGA), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Sample x = 0.20 has shown maximum conductivity of 1.2 × 10^-3 S/cm with minimum activation energy of 0.19 eV at 800°C. Along with this, maximum thermal expansion coefficient (TEC) is observed for x = 0.2 sample. The microstructures of the samples exhibited variation in grain size and porosity.