Enhanced magnetization and suppressed current leakage in BiFeO3 ceramics prepared by spark plasma sintering of sol-gel derived nanoparticles

BiFeO3 (BFO) ceramics of different grain size have been synthesized by spark plasma sintering of sol-gel derived nanoparticles. It was found that with decreasing grain size there occurs an enhancement in magnetization and a simultaneous suppression in current leakage. According to systematic materials characterization, the enhanced magnetization is attributed to the enriched grain boundaries where the missing structural order perturbs the spin helix structure of BFO and thus generates uncompensated spins, while the reduced current leakage is ascribed to fewer conduction paths provided by the compacted grain structure. (C) 2012 Elsevier B.V. All rights reserved.