Colossal Room-Temperature Magnetoelectric Coupling in Anion-Deficient Layered Perovskite Films with Ordered Cation Distribution

The anion-deficient layered perovskite Pb 2 Fe 2 O 5, featuring a polarizable active Pb cation with lone pair electrons and a magnetically active transition metal Fe cation, presents a promising candidate for multiferroic applications. Nonetheless, the exploration of multiferroic properties and magnetoelectric coupling in Pb 2 Fe 2 O 5 is extremely rare due to its complex structure. Herein, a colossal magnetoelectric coupling coefficient (5.19 × 10 5 mV cm –1 Oe –1 ), high ferroelectric polarization (2 μC/cm 2 ), and magnetic moment (25 emu/cc) at room temperature have been discovered in an epitaxial Pb 2+0.48 Fe 2 O 5 film. The findings of this study demonstrate that the introduction of excessive Pb ions can disrupt the disordered arrangement of the mixed layer and convert it to an ordered distribution to improve ferroelectric properties. This research not only enriches the magnetoelectric coupling material system but also offers a viable strategy for achieving strong room-temperature magnetoelectric coupling and multiferroicity in layered oxide materials.