Atomic Origins of Magnetic Anisotropy in Ru-substituted Manganite Films

Magnetic anisotropy in complex oxides often originates from the complex interplay of several factors, including crystal structure, spin-orbit coupling, and electronic interactions. Recent studies on Ru-substituted $La_{0.70}Sr_{0.30}MnO_3$ (Ru-LSMO) films demonstrate emerging magnetic and magneto-transport properties, where magnetic anisotropy plays a crucial role. However, the atomic origin and underlying mechanisms of the magnetic anisotropy of this material system remain elusive. This work sheds light on these aspects. Detailed element-specific X-ray magnetic dichroism analysis suggests that Ru single ion anisotropy governs the overall magnetic anisotropy. Furthermore, the magnetic property of Mn ions changes dramatically due to strong antiferromagnetic coupling between Ru and Mn ions. Our findings clarify the role of Ru single ion anisotropy behind magnetic anisotropy in Ru-LSMO, offering a promising avenue for designing advanced materials with tailored magnetic properties for next generation magnetic and spintronic technologies. As the Curie temperature of these materials is close to room temperature, such tunable magnetic anisotropy holds prospects for functional room-temperature magnetic devices.