EFFECT OF Ca DOPING ON STRUCTURAL, OPTICAL, MAGNETIC AND DIELECTRIC PROPERTIES OF BiFeO3 NANOPARTICLES.

We proposed Sol-gel method to study the structure, optical, magnetic and dielectric properties of Bi1-xCaxFeO3 (x= 0.00, 0.01, 0.02, 0.03, 0.04 and 0.05) nano particles. The XRD spectrum exhibited predominant (012) and (110) orientation peaks at 2θ = 31.9o and 2θ = 32.1o corresponding to rhombohedral structure with R3c space group. From optical studies the band gap of BFO and Ca doped BFO nanoparticles were decreased from 2.13 to 1.96eV. The observed narrow band gap in the BFO system opens new vistas for the application of this material as multiferroic semiconductor. From magnetic properties the saturation magnetization for BFO (2.90 emu/gm) and for Ca doped BFO increased significantly from 1.00 emu/gm to 3.29 emu/gm. Dielectric and electric properties were studied over a frequency range of 10 Hz ? 1 MHz. The dielectric constant was observed to decrease with increase in frequency. From cole-cole plots, as the Ca concentration increases, all semicircles become bigger and shift towards higher-frequency region, indicating a increment of grain and grain boundary resistance