Ferromagnetism of LaCoO${}_3$ films

Abstract

We study ferromagnetic ordering and microscopic inhomogeneity in tensile strained LaCoO${}_3$ using numerical simulations. We argue that both phenomena originate from effective superexchange interactions between atoms in the high-spin (HS) state mediated by the intermediate-spin excitations. We derive a model of the HS excitation as a bare atomic state dressed by electron and electron-hole fluctuations on the neighbor atoms. We construct a series of approximations to account for electron correlation effects responsible for HS fluctuations and magnetic exchange. The obtained amplitudes and directional dependence of magnetic couplings between the "dressed" HS states show a qualitative agreement with experimental observations and provide a new physical picture of LaCoO${}_3$ films.

arXiv comment23 pages, 9 figures, Submission to SciPost

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Cited by in corpus (2)

• Two Spin-State Crystallizations in LaCoO${}_3$
• Optical signatures of strain-induced ferromagnetism in LaCoO${}_3$ thin film