Designing complex exchange interaction pathways in spinel films using entropy stabilization*

Magnetic behaviors in AB₂O₄ spinels are dictated by the magnetic exchange interactions within and between the tetrahedral and octahedral sublattices. Functionality is then tied directly to the distribution and type of cations present within the unit cell. We will present our recent work developing entropic stabilization to synthesize single-crystal high entropy spinel oxide films of the AB₂O₄ type, where the cation sites are populated by 5 or more elements. We will describe how cation selection can be used to modify the type and strength of exchange interactions present in the crystal lattice. Lab-scale magnetic and structural characterization combined with beamline-based x-ray spectroscopy and neutron diffraction demonstrate the presence of highly tunable and varied magnetic responses; including: room temperature ferrimagnetic insulating states, surface-stabilized spin textures, tunable compensation points, and extraordinarily high strain-induced magnetic anisotropy.