Structural, electrical and magnetic properties of (Bi_0.9RE_0.1)(Fe_0.97Co_0.03)O₃ (RE = Nd and Gd) thin films

Highlights: • Nd–Co and Gd–Co codoped BiFeO₃ thin films are synthesized by chemical solution deposition method. • Enhanced magnetic property is observed in BGFC thin film at room temperature. • The onset electric field of FN tunneling of the films is associated with band gaps. • Both ferromagnetism and diamagnetism coexist in the BNFC film. - Abstract: Rhombohedral (Bi_0.9RE_0.1)(Fe_0.97Co_0.03)O₃ (RE = Nd and Gd) thin films were deposited on FTO substrates by using a chemical solution deposition method. Raman scattering spectra reveal that the BiFeO₃ lattices are able to incorporate Nd/Gd and Co ions with no effect on the basic rhombohedral structure. The chemical shift of Bi 4f, Fe 2p and O 1s core levels of the films is investigated by the X-ray photoelectron spectroscopy (XPS) analysis. The presence of defects in the films has been estimated through XPS study, which has a great effect on the dielectric dispersion and ferroelectric polarization. The intrinsic density of free electrons associated with band gap is the dominating factor which controls the FN tunneling conductance mechanism of the films. Both ferromagnetism and diamagnetism coexist in the BNFC film, while only ferromagnetism is observed in the BGFC film