Multiferroic properties of BiFeO3 thin films with Ce substitution

In this study, we investigated the crystalline structure, ferroelectricity, leakage current density, magnetic, and nanomechanical properties of BiFeO3 (BFO) films with Ce substitution. Bi1-xCexFeO3 (BCFO) films with x = 0.00, 0.03, 0.06, 0.09, and 0.15 were deposited on glass substrates by using pulsed laser deposition. The experimental results showed that the BCFO films mainly composed the perovskite phase. The structure changed from rhombohedral when x = 0.00 to pseudo-cubic when x = 0.03, and pseudo-cubic phase coexisted with an additional Bi2Fe4O9 phase when x = 0.06–0.09. The BCFO films exhibited improved ferroelectricity and desirable magnetic characteristics. The remanent polarization (2Pr) increased significantly with the Ce concentration, reaching 189.3 μC/cm2 and 100.0 μC/cm2 when x = 0.03 and x = 0.06, respectively, but decreasing at higher Ce contents. The BCFO film with x = 0.03 had a remarkable 2Pr value of 189 μC/cm2 after 108 cycles due to the high (110) texture, fine microstructure, and flat interface resulting in strong anti-fatigue properties. The leakage mechanisms in the BCFO films were also examined. The films exhibited enhanced saturation magnetization (Ms) values ranging from 3.8 to 10.0 emu/cm3, which were attributed to suppression of the spiral spin configuration and the larger magnetic moment associated with the Ce3+ ion. The nanomechanical characteristics of the BCFO films, such as hardness, were significantly influenced by the grain size and phase composition. These findings provide valuable insights into enhancement of the multiferroic properties of BFO polycrystalline films through Ce substitution for use in various applications. •A pure perovskite phase is present for Ce-doped BFO films on Pt(111) electrodes.•Ce-doped BFO films exhibited excellent ferroelectric properties.•Ce-doped BFO films showed the improved magnetization.•Ce-doped BFO films on glass substrate should be a useful multiferroic material for the applications.