Electrical and energy storage properties of nickel substituted barium bismuth niobate nano-ceramics prepared by chemical route

Nanosized barium nickel bismuth niobate (Ba_1−xNi_xBi₂Nb₂O₉) powders with x = 0.5, abbreviated as BNiBN is prepared through aqueous based chemical method. X-ray diffraction (XRD) analysis and electrical measurements are performed. XRD analysis establishes the orthorhombic structure of BNiBN with A2₁am (36) space group. The highest intensity peak is (115), which supports bismuth layer structured ferroelectrics of (112m + 1) type. The dielectric study establishes the relaxor behaviour with temperature maxima 150 °C at 10 kHz. Cole–Cole plot of impedance have single semicircle that correlate with grain conductivity. Imaginary impedance versus frequency has relaxation behaviour and activation energy of 0.75 eV is observed. The ac conductivity at high temperature exhibits the hopping behaviour. The charging and discharging energy density and charge–discharge efficiency are calculated from the polarization study at different electric field. The material exhibits a high energy density (> 12 J cm⁻³) and a high charge–discharge efficiency (> 83%) at room temperature.