Enhancing Magneto-Optical Performance in LaFeO3 Thin Films via Cubic-Phase Transition Induced by Ce3+/Ti4+ Co-Doping

Birefringence, arising from the low-symmetry structure in orthorhombic LaFeO3, limits the observation and utilization of magneto-optical effects. In this study, the pure-phase perovskite-typed La1−xCexFe1−xTixO3/SiO2 thin films were successfully fabricated via radio-frequency magnetron sputtering, where the co-doping of Ce3+ and Ti4+ ions effectively induced a structure transition from orthorhombic to a highly symmetric cubic phase, eliminating birefringence effect and thus reducing optical transmission loss. At the same time, the doped Ce3+ ions also effectively enhanced the magnetic and magneto-optical effects of the system due to their strong spin coupling effect and superexchange interaction with Fe3+ ions. The results show that the cubic-phase La0.5Ce0.5Fe0.5Ti0.5O3/SiO2 thin film exhibits excellent magnetic and magneto-optical performance. Their saturation magnetization reaches 180 emu/cm3 with an in-plane easy magnetic axis. And their magnetic circular dichroic ellipticity |ψF| reaches 3054 degrees/cm.