Influence of vanadium doping on the processing temperature and dielectric properties of barium bismuth niobate ceramics

Abstract

Barium bismuth vanadium niobate, BaBi 2(Nb 1− x V x ) 2O 9 (0 ≤ x ≤ 0.1) ceramics were fabricated from the powders prepared via solid state reaction route. The single phase layered perovskite structure was preserved up to 5 at% ( x = 0.05) of vanadium. The addition of V 2O 5 substantially improved the sinterability associated with high density (96%) which was otherwise difficult in the case of pure BaBi 2Nb 2O 9 (BBN). The sintering temperature was significantly reduced from 1100 to 900 °C. The scanning electron microscopic (SEM) studies revealed the transformation of a porous microstructure to a well-packed platy grained with negligible inter-granular porosity. The dielectric constant of BBN ceramics at both room temperature and in the vicinity of the temperature of dielectric maximum ( T m) has increased significantly with increase in vanadium content and the loss remained almost constant. The T m increased with increase in V 2O 5. For instance, there was an upward shift of about 25 °C in T m for 5 at% ( x = 0.05) vanadium-doped BBN. Interestingly, the diffuseness ( γ) in the phase transition was found to decrease with increase in vanadium doping level.