Investigation on electrical, magnetic and magneto-dielectric properties of yttrium and cobalt co-doped bismuth ferrite nanoparticles

Abstract

Yttrium and cobalt co-doped multiferroic bismuth ferrite (BFO) nanopowder (Bi1−xYxFe1−yCoyO3 with x = 0.00, y = 0.0, 0.05 and x = 0.05, y = 0.05, 0.1, 0.15) was synthesized by using sol–gel method. The as-grown powder was found to be amorphous that crystallizes to the desired phase after annealing at 600 °C for 2 h in the air. X-ray diffraction pattern confirms the formation of the pure-phase BFO, and with increasing the content of yttrium and cobalt, the two dominant split peaks merge. But for x = 0.05, y = 0.15 sample, the splitting again appears. The chemical bonding between Fe–O and Bi–O was identified by the FTIR analysis. The samples show the high-frequency dispersion of dielectric constant and loss tangent at low frequency. The improved AC conductivity was observed for the doped samples. The electrical polarization was enhanced with increasing content of yttrium and cobalt in the sample. The magnetic properties of the doped samples were also found to be enhanced. The retentivity of the samples increased from 0.15 emu/g (x = 0.0, y = 0.0) to 0.63 emu/g (x = 0.05, y = 0.1) with increasing the content of yttrium and cobalt. The effect of the magnetic field on the dielectric constant was analyzed by considering the magneto-dielectric coefficient. The results were analyzed in light of the reported results in the literature.