Ferromagnetism of LaCoO.sub.3./sub. films

0534735 - FZÚ 2021 RIV NL eng J - Journal Article
Sotnikov, A. - Ahn, K-H. - Kuneš, Jan
Ferromagnetism of LaCoO₃ films.
SciPost Physics. Roč. 8, č. 6 (2020), s. 1-21, č. článku 082. ISSN 2542-4653. E-ISSN 2542-4653
EU Projects: European Commission(XE) 646807 - EXMAG
Institutional support: RVO:68378271
Keywords : spin-state transition * electronic-structure * model
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 6.093, year: 2020
Method of publishing: Open access

We study ferromagnetic ordering and microscopic inhomogeneity in tensile strained LaCoO3 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 LaCoO3 films.
Permanent Link: http://hdl.handle.net/11104/0312913