Large magnetization and weak polarization in sol–gel derived BiFeO3 ceramics

Abstract

Single-phase multiferroic BiFeO3 (BFO) ceramics were prepared by sol–gel technique after annealing in different atmospheres followed by leaching in dilute nitric acid. Ar annealing was effective in reducing impurity phases present with BFO phase. The BFO ceramics exhibit a dense and uniform surface morphology with grain size of ∼200 nm. Air annealed BFO ceramic showed weak ferromagnetism while Ar annealed BFO exhibited ferromagnetic ordering at room temperature. The dielectric constant and dielectric loss showed low frequency dispersion for both the ceramics at room temperature. No saturation in polarization–electric field (P–E) curve could be obtained for both the ceramics exhibiting weak ferroelectric characteristic.