Charge Compensation Mechanism and Multifunctional Properties of Bi1−xBaxFeO3 (x = 0, 0.05, 0.1) Ceramics

Abstract

The charge compensation mechanism of Ba2+ ion doped BiFeO3 (BFO) has been studied here in detail. The most common problem of high leakage current of ceramic BFO was noticeably resolved by significant reduction of charge defects through Ba2+ doping. The leakage current density of Bi1-xBaxFeO3 (x = 0, 0.05, 0.1) was found to be reduced to ∼3.13 × 10−8 A cm−2 for x = 0.1 from a value of 2.26 × 10−4 A cm−2 for x = 0 at an applied field of 500 V cm−1. This reduction of leakage current was caused by the reduction of charge defects which was verified through the X-ray photoelectron spectroscopy (XPS). The dielectric and ferroelectric properties of undoped and Ba2+ doped BFO were also studied here explicitly and correlated with charge compensation mechanism. The structural and vibrational characterization proved the phase pure formation and the presence of metal-oxide bonds. The optical characterization showed the reduction in energy band gap with increased Ba2+ doping in BFO (2.18, 1.71 and 1.56 eV for x = 0, 0.05 and 0.1, respectively). Another common problem of BFO, namely low remanent magnetization, was also significantly resolved through Ba2+ doping in it and the strong antiferromagnetic BFO started showing weak ferromagnetic nature with increased doping concentration.