Perovskite heterostructures are remarkable materials because of their broad electrical and magnetic properties. Cation intermixing is one aspect of these systems that have not been explored in much detail. We have studied the stability and effects of cation intermixing in multiple magnetic structures of the perovskite heterostructure LaCoO₃/SrFeO₃. Calculations were performed with the PBE+U method as implemented in VASP. The energetics, magnetic moments, and spin-densities were analyzed for (LaCoO₃)₁/(SrFeO₃)_n (n = 2, 3, 4, and 5). The calculations show that the model systems (LaCoO₃)₁/(SrFeO₃)_n are more stable in the ferromagnetic configuration. To study the effects of cation intermixing in the magnetic structures of these systems, we use the models 1) La-Co-(Sr-Fe)₅, 2) La-Fe-Sr-Co-(Sr-Fe)₄, and 3) La-Fe-Sr-Fe-Sr-Co-(Sr-Fe)₃. The results show that models 2) and 3) are +0.12 eV and +3.15 eV less stable than model 1). The calculations indicate that the cation intermixing Co and Fe near the interface is energetically feasible. The La-Fe-Sr-Co-(Sr-Fe)₄ is also stable in the ferromagnetic configuration. The results of our calculations can help understand the relationship between cation intermixing and magnetic structure.

Models of cation intermixing in (LaCoO<sub>3</sub>)<sub>1</sub>/(SrFeO<sub>3</sub>)<sub>5</sub>.

Models of cation intermixing in (LaCoO₃)₁/(SrFeO₃)₅.

David Gonzalez

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