Oxygen Vacancy Engineering for Highly Tunable Ferromagnetic Properties: A Case of SrRuO3Ultrathin Film with a SrTiO3Capping Layer

Oxide heterostructures have great potential for spintronics applications due to their well-defined heterointerfaces and vast functionalities. To integrate such compelling features into practical spintronics devices, effective control of the magnetic switching behavior is key. Here, continuous control of the magnetic coercive field in SrTiO3/SrRuO(3)ultrathin heterostructures is achieved by oxygen vacancy (V-O) engineering. Pulsed laser deposition of an oxygen-deficient SrTiO(3)capping layer can trigger V(O)migration into the SrRuO(3)layer while avoiding the formation of Ru vacancies. Moreover, by varying the thickness and growth conditions of the SrTiO(3)capping layer, the value of the coercive field (H-C) in the ferromagnetic SrRuO(3)layer can be continuously tuned. The maximum enhancement ofH(C)at 5 K is 3.2 T. Such a wide-range tunability ofH(C)may originate from a V-O-induced enhancement of perpendicular magnetic anisotropy and domain wall pinning. This study offers effective approaches for controlling physical properties of oxide heterostructures via V(O)engineering, which may facilitate the development of oxide-based functional devices.