Ferromagnetism of LaCoO$_3$ films
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 der...
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| Format: | Article |
| Language: | English |
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SciPost
2020-06-01
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| Series: | SciPost Physics |
| Online Access: | https://scipost.org/SciPostPhys.8.6.082 |
| Summary: | 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. |
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| ISSN: | 2542-4653 |