Electronic structure correlation with ferroelectric behavior of Ca-doped BiFeO3 films

•Fabrication of Ca-doped BiFeO3 films using Pulsed Laser Deposition.•Improvement in the ferroelectric behavior of BiFeO3 films with Ca-doping.•Role of strong hybridization between Fe3d–O2p for the improvement in ferroelectric behavior. Effect of Ca – doping on electronic structure and ferroelectric properties have been studied on PLD grown Bi1-xCaxFeO3/SNTO (x = 0.05, 0.10, 0.20) films. The structural study confirms single crystalline (100) oriented epitaxial growth of the films. The observed improvement in the ferroelectric behavior with an increase in Ca – doping has been attributed to the strong hybridization between Fe3d–O2p and localization of Fe3deg and Bi6s-O2p orbitals understood using X-ray Absorption Spectroscopy measurements. Ferroelectric measurements performed on BCFO films show the finite value of intrinsic ferroelectric polarization, though the contributions from the non – ferroelectric components lead to unsaturated and leaky loop. The sub-bandgap transition observed in the absorption spectra indicates the presence of oxygen vacancy states which is one of the reasons for observed leakage in polarization measurements.