Neutron-scattering-based evidence for interacting magnetic excitons in LaCo O3

S. El-Khatib, D. Phelan, J. G. Barker, H. Zheng, J. F. Mitchell, C. Leighton

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

Recent progress with the thermally driven spin-state crossover in LaCoO3 has made it increasingly apparent that the nominally nonmagnetic low-spin ground state of this material actually hosts defect-based magnetism. This is investigated here via a small-angle neutron scattering (SANS) study of LaCoO3-δ crystals. The results provide (i) the surprising finding that the spin-state crossover is clearly reflected in SANS via quasieleastic and inelastic scattering from paramagnetic spin fluctuations and excitations, and (ii) evidence for the formation, likely around oxygen defects, of local entities known as magnetic excitons. The latter generate distinct magnetic scattering below 60 K, providing valuable quantitative information on exciton densities and interactions. Potential relevance to the unexpected ferromagnetism recently discovered in epitaxial LaCoO3 films is discussed.

Original languageEnglish (US)
Article number060404
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume92
Issue number6
DOIs
StatePublished - Aug 6 2015

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Neutron scattering
Excitons
neutron scattering
excitons
Spin fluctuations
Defects
Inelastic scattering
Ferromagnetism
Epitaxial films
Magnetism
Ground state
crossovers
Scattering
Oxygen
Crystals
defects
scattering
ferromagnetism
inelastic scattering
ground state

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Neutron-scattering-based evidence for interacting magnetic excitons in LaCo O3. / El-Khatib, S.; Phelan, D.; Barker, J. G.; Zheng, H.; Mitchell, J. F.; Leighton, C.

In: Physical Review B - Condensed Matter and Materials Physics, Vol. 92, No. 6, 060404, 06.08.2015.

Research output: Contribution to journalArticle

El-Khatib, S. ; Phelan, D. ; Barker, J. G. ; Zheng, H. ; Mitchell, J. F. ; Leighton, C. / Neutron-scattering-based evidence for interacting magnetic excitons in LaCo O3. In: Physical Review B - Condensed Matter and Materials Physics. 2015 ; Vol. 92, No. 6.
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