Optical and Dielectric studies of La doped BiFeO3

Abstract

Polycrystalline samples of La modified Bismuth Ferrite (Bi1-x Lax FeO3) with different compositions; x=0.0, 0.1, and 0.2 were prepared by the wet chemical route viz. Sol Gel Autocombustion method. XRD studies clearly showed the formation of rhombohedral phase for undoped BiFeO3. With the increase in La concentration, the crystal structure showed transformation to orthorhombic. From the absorption spectra the band gap of nanoparticles were calculated and found to be dependent upon La-content. Frequency dependence of dielectric constant and dielectric loss in the range of 10 Hz to 1 MHz was studied at room temperature. High temperature dielectric studies showed a decrease in antiferromagnetic Neél temperature with increase in La content.