Structural, optical and enhanced electrical properties of vanadium alloyed sodium bismuth titanate solid solution synthesized by a chemical-mechanical hybrid method

Abstract

This work focuses on the effect of V2O5 addition on the structural, optical and electrical properties of Sodium Bismuth Titanate (Na0.5Bi0.5TiO3) nanomaterials, for its possible application as an electrolyte in SOFC. Pure Na0.5Bi0.5TiO3 (NBT) material has been synthesized using citrate auto-ignition method and V2O5 has been reinforced in the perovskite structure by mechanical alloying. X-ray diffraction analysis confirms the formation of the rhombohedral phase of NBT perovskite with space group R3c. Rietveld Analysis indicates the presence of insoluble minor V2O5 phase in the 20% milled composition. The values of lattice parameters, particle size, and the microstrain have been found to vary with V2O5 addition. The presence of different bonds has been confirmed from FT-IR analysis. It has been found that the vanadium incorporation can tune the optical bandgap of the material. The real part of complex ac conductivity has been found to follow universal Jonscher power law. The variation in conductivity is correlated with the structural changes due to V2O5 addition. The highest conductivity achieved was 1.0143 × 10−4 at 400 °C for the 15% doped composition. The conductivity mechanism has been explained by Mott’s variable range hopping model.