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.

23 pages, 9 figures, Submission to SciPost

References in corpus (8)

• The spin state transition in LaCoO${}_3$; revising a revision
• Strain-Induced Spin States in Atomically Ordered Cobaltites
• Structural effects on the spin-state transition in epitaxially strained LaCoO${}_3$ films
• Reversible strain effect on the magnetization of LaCoO3 films
• Spin state transition and covalent bonding in LaCoO3
• Disproportionation and Metallization at Low-Spin to High-Spin Transition in Multiorbital Mott Systems
• Importance of exchange-anisotropy and superexchange for the spin-state transitions in LnCoO3 (Ln=La,Y,RE) cobaltates
• Coulomb correlations intertwined with spin and orbital excitations in LaCoO${}_3$

Cited by in corpus (1)

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