Cooperative control of perpendicular magnetic anisotropy via crystal structure and orientation in freestanding SrRuO 3 membranes

Flexible magnetic materials with robust and controllable perpendicular magnetic anisotropy (PMA) are highly desirable for developing flexible high-performance spintronic devices. However, it is still challenge to fabricate PMA films on polymers directly. Here, we report a facile method for synthesizing single-crystal freestanding SrRuO 3 membranes with controlled crystal structure and orientation using water-soluble Ca 3-x Sr x Al 2 O 6 sacrificial layers. Through cooperative effect of crystal structure and orientation, flexible membranes reveal highly tunable magnetic anisotropy from in-plane to out-of-plane with a remarkable PMA energy of 7 × 10 6 erg·cm −3 . First-principle calculations reveal that the underlying mechanism of PMA modulation is intimately correlated with structure-controlled Ru 4 d -orbital occupation, as well as spin-orbital matrix element differences, dependent on the crystal orientation. In addition, even after 10,000 bending cycles, the PMA keeps stable, indicating a robust magnetism reliability in the prepared films. This work provides a feasible approach to prepare the flexible oxide films with strong and controllable PMA.