Electrical transport properties of layered structure bismuth oxide: Ba_0.5Sr_0.5Bi₂V₂O₉

The layered structure bismuth oxide, Ba_0.5Sr_0.5Bi₂V₂O₉, was prepared using solid state reaction technique. Room temperature X-ray diffraction study confirms the formation of the material with an orthorhombic crystal structure. The temperature dependent impedance parameters were investigated using an impedance analyzer in a wide range of frequencies (10²–10⁶ Hz) at different temperatures. The Nyquist plots reveal the presence of both grain and grain boundary effect above 275 °C. The bulk resistance of the material decreases with rise in temperature which shows negative temperature coefficient resistance behavior like semiconductor. The variation of ac electrical conductivity (σ_ac) was measured, and the activation energy of the material found to be 0.36, 0.33, 0.34, 0.31 eV at 10, 50, 100 and 500 kHz respectively. Ac conductivity data were used to evaluate the density of states at Fermi level. From the dynamic light scattering and electrophoretic light scattering study, it is observed that the particle show excellent aqueous dispersion stability without any change in hydrodynamic size and zeta potential.