Heterogeneously integrated freestanding oxide membrane with multiferroicity*

Transition metal oxides exhibit diverse electrical and magnetic characteristics, which are influenced by their order parameters. Ferroic orderings offer a wide range of important scientific phenomena and practical uses. To create multiferroic oxides successfully, a promising approach involves combining ferroelectric (FE) and ferromagnetic (FM) materials. The development of freestanding, heterogeneous membranes containing these multiferroic oxides is highly desirable.

In this study, we employed pulsed laser epitaxy to create freestanding bilayer membranes made of BaTiO₃ and La_0.7Sr_0.3MnO₃ [1]. These membranes display ferroelectric and ferromagnetic properties at room temperature, along with a measurable magnetoelectric (ME) coupling coefficient. Our research highlights the importance of achieving freestanding heterostructures in determining their structural and emerging qualities. When not clamped by the substrate, the magnetic orientation axis undergoes reorientation, resulting in perpendicular magnetic anisotropy due to changes in the orbital occupancy of the magnetic layer. These findings open the door to integrating these flexible membranes into electronic applications.