Enhanced multiferroic properties of BiFeO₃ thin films by Nd and high-valence Mo co-doping

Pure BiFeO₃ (BFO), Nd-doped BFO (BNF) and Nd and Mo co-doped BFO (BNFM) multiferroic thin films were prepared by pulsed laser deposition on Pt/Ti/SiO₂/Si substrates. Among these films, the BNFM film exhibited the lowest dielectric loss and leakage current density, a well-saturated P-E loop, excellent charge-retaining ability and fatigue-free behaviour. Furthermore, improved ferromagnetism was observed in this film with a saturation magnetization of ∼15 emu cm^-3. These significant improvements in ferroelectric and ferromagnetic properties could be preliminarily attributed to the elimination of oxygen vacancies and the increase in the Fe²⁺ ions in the film by Nd and high-valence Mo co-doping, respectively.