Multiferroic properties of Bi0.95R0.05FeO3 polycrystalline films on the glass substrates (R = La, Pr, Nd, Sm, and Ho)

Abstract Multiferroic properties of Bi0.95R0.05FeO3 films (R = La, Pr, Nd, Sm, and Ho) (BRFO) on glass substrates at reduced formation temperature of 450°C via pulsed laser deposition have been investigated. XRD result shows that perovskite phase is found for all studied BRFO films, but an additional phase, Bi2Fe4O9, coexists for Ho-doped BFO film. For all BRFO films, a fine microstructure with a flat surface is observed. The studied BRFO polycrystalline films exhibit coexistence of good ferroelectric and ferromagnetic properties. The remanent polarization (2Pr) of 57-113 μC/cm2 and electrical coercive field of 210-384 kV/cm is obtained, while the saturation magnetization (Ms) of 6.6-20.3 emu/cm3 and coercivity of 400-600 Oe is attained. The relationship between 2Pr and the ionic radius of R3+ for the BRFO films indicates that R3+ ionic radius may mainly dominate the polarization of BRFO films. The change of Ms with R is related to the magnetic moment of the doped R3+ ion. Besides, the leakage mechanism of BRFO films with R is also discussed. The result in this study suggests multiferroic properties of Bi0.95R0.05FeO3 polycrystalline films could be well tuned by R.