Engineering Magnetic Interactions in Complex Oxide Heterostructures*

Due to the strong interaction between the charge, spin, lattice, and orbital degrees of freedom, complex oxides possess a wide range of technologically relevant properties such as ferromagnetism, ferroelectricity, and superconductivity. Interfacial interactions provide additional sources of emergent behavior which enable the engineering of spin textures when patterned down to nanoscale dimensions. When patterned using a local structural modification from an ion implantation process, a complex 3D strain state develops within the magnetic islands from the combined effects of the underlying substrate and the surrounding amorphous matrix. As a result, distinctive and coupled ferromagnetic (FM) and antiferromagnetic (AFM) spin textures are observed in heterostructures composed of FM La_0.7Sr_0.3MnO₃ and AFM La_1-xSr_xFeO₃ sublayers. These spin textures can be manipulated using magnetic parameters such as exchange interactions, as well as shape and magnetocrystalline anisotropy energies. These studies demonstrate that complex oxide heterostructures provide a unique platform for engineering spin textures for future memory and spintronic device applications.