Cooperative Atomic Mechanism of Emergent Tilted Magnetic Anisotropy

Understanding the atomic origin of magnetic anisotropy is of paramount importance for designing advanced magnetic materials for the next generation of magnetic and spintronic technologies. The Ru‐substituted La 0.70 Sr 0.30 MnO 3 (Ru‐LSMO) system has recently attracted attention due to its attractive magnetic and magneto‐transport properties, where magnetic anisotropy plays a pivotal role. However, the atomic mechanisms governing magnetic anisotropy in this material system remain elusive, hindering technological maturation. Here, a novel cooperative atomic mechanism is identified for emergent tilted magnetic anisotropy (TMA) in Ru‐LSMO films. Using element‐specific X‐ray magnetic dichroism (XMCD), it is uncovered that macroscopic TMA stems from the cooperation of single‐ion anisotropy in the Ru ions and antiferromagnetic exchange interaction with the Mn ions. Remarkably, despite the absence of single‐ion anisotropy, the Mn ions exhibit robust TMA because of this exchange interaction, transforming the otherwise in‐plane magnetic anisotropy in Mn ions of pure LSMO. These phenomena persist to near room temperature, underscoring the technological potential. These findings open a promising route for atomic‐scale engineering of magnetic anisotropy, paving the way for the next generation magnetic and spintronic technologies.