Dielectric and Electrical Properties of Barium and Nickel Doped LaFeO3

In this paper we report the role of barium doping at A-site and nickel doping at B-site in LaFeO3 ceramics synthesised by Co-precipitation route for tailoring its dielectric and electrical properties. Shifts in the X-ray diffraction peaks indicate distortion induced in host lattice due to Ba/Ni doping. The morphology of the ceramics is studied using scanning electron miscropy. Plate-like grains stacked over one another are observed in Ba-doped and Ni-doped LaFeO3 ceramics. Barium doping is found to improve dielectric properties due to the higher polarizability of barium ion. Nickel-doped LFO shows higher ionic conductivity as compared to Ba-doped LFO because of toggling of the ionic state of Fe3+ to Fe4+ for charge compensation. The conduction mechanism in these ceramics is evaluated using Nyquist plots. Grain boundary resistance is found to dominate in all the samples. Barium doping increases the capacitive nature of LaFeO3 with increase in the Ba concentration.