Thin Films through Ion Implantation*

Control of the functional properties of thin films, including the magneto-crystalline anisotropy, is critical for the development of future memory and spintronic devices. Perovskite oxides offer stimulus-sensitive properties due to the strong coupling between their spin, orbital, lattice, and charge degrees of freedom. In this work, we found that ion implantation of La_0.7Sr_0.3MnO₃ films induces changes in the magnetic anisotropy by causing an out-of-plane lattice expansion while the film remains coherently strained to the substrate. However, the ion implantation also leads to a reduction in Curie temperature and saturation magnetization. X-ray absorption spectroscopy shows this degradation in magnetic properties is in part due to the reduced Mn oxidation state, in addition to crystalline damage. With the proper substrate selection and optimization of ion implantation conditions, the easy axis of the film can be tuned from in-plane to out-of-plane while minimizing the reduction in magnetization. These results may enable the design of unique magnetic spin textures such as magnetic skyrmions in a single layer of material containing adjacent regions of in-plane and out-of-plane magnetization.