Multiferroic properties of Bi0.95H0.05FeO3 polycrystalline films (H = Gd, Tb, Dy, Ho, Er)

Abstract

We investigated the structure, ferroelectric, magnetic, and leakage characteristics of Bi0.95H0.05FeO3 (BHFO) polycrystalline films with H = Gd, Tb, Dy, Ho, and Er. Bi0.95H0.05FeO3 films were confirmed to mainly consist of the perovskite phase, and the phase structure belongs to the pseudo-cubic phase. The desired ferroelectric and ferromagnetic properties at the same time, the remanent polarization (2Pr) of 57–81 μC/cm2 and the saturation magnetization (Ms) of 11.6–21.3 emu/cm3, are obtained for Bi0.95H0.05FeO3 films. Lower 2Pr with smaller ionic radius of H is possibly related to limited ion movement because of the reduced volume of the unit cell in BHFO films. Low leakage current characteristics and leakage mechanisms in Bi0.95H0.05FeO3 films are also discussed. In aspect of the magnetic properties, H can significantly improve the magnetic properties of BFO by A-site substitutions due to the suppressed spiral structure and importantly the contribution of high magnetic moment of H ion. The results of this work suggests BHFO films is a good multiferroic material, especially the samples with H = Tb and Dy.