Flexomagnetic Effect in Wrinkled SrRuO ₃ Thin Films

ABSTRACT

The coupling between strain gradients and magnetic spins in perovskite thin films has long been a key focus of magnetism research, representing one of the essential pathways toward the realization of functional and flexible magnetic sensors and data storage systems. In this context, we confirm that the strain‐gradient‐driven flexoelectric polarization can modify the magnetic moment of SrRuO ₃ (SRO) film. Given that conventional epitaxial methods often have some limitations (such as substrate clamping effect, localization of strain gradient), we propose to achieve controllable flexoelectric modulation of the magnetic properties in SRO thin films via employing the wrinkles. Results show that the flexoelectric polarization induced by wrinkling can modulate spin co‐orientation, thereby enhancing the local magnetic properties of the SRO thin films, exhibiting opposite trends in magnetic moment variations at the crests and troughs of the wrinkles. Furthermore, the overall asymmetry of the wrinkle morphology governs the enhancement of the macroscopic magnetic properties of the SRO films; the saturation magnetization of the wrinkled film increases nearly tripling. This study offers new insights into strain gradient―spin coupling in perovskite oxides, while the introduction of wrinkle structures expands the application scope of the flexoelectric effect in the field of flexible devices.