Significantly suppressed leakage current and reduced band gap of BiFeO3 through Ba–Zr Co-Substitution: Structural, optical, electrical and magnetic study

Abstract

Bismuth Ferrite (BFO), Ba substituted BFO (BBFO) and Ba–Zr co-substituted BFO (BBFZO) nanoparticles have been synthesized via citrate-gel route. The common problem of BFO i.e; compositional instability, low magnetization and high leakage current was resolved by this doping technique. Remanent magnetization and remanent polarization improved significantly for BBFZO sample compared to that of BFO. Structural, optical and improved dielectric properties were also investigated. Structural study confirmed the enhanced structural distortion in BFO due to doping of Ba and Ba–Zr ions. The calculated energy band gap has been reduced to 1.52 eV for BBFZO nanoparticles from a value of 2.55 eV for BFO. Leakage current was suppressed by almost seven orders of magnitude for Ba–Zr co-substituted bulk BFO compared to that of undoped BFO. Morphological study of bulk samples has shown gradual reduction in grain size upon Ba doping and Ba–Zr co-doping in BFO, respectively.