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Local Moment Instability of Os in Honeycomb Li(2.15)Os(0.85)O(3)

Compounds with honeycomb structures occupied by strong spin orbit coupled (SOC) moments are considered to be candidate Kitaev quantum spin liquids. Here we present the first example of Os on a honeycomb structure, Li(2.15(3))Os(0.85(3))O(3) (C2/c, a = 5.09 Å, b = 8.81 Å, c = 9.83 Å, β = 99.3°). Neut...

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Autores principales: Wallace, M. K., LaBarre, P. G., Li, Jun, Pi, S.-T., Pickett, W. E., Dessau, D. S., Haskel, D., Ramirez, A. P., Subramanian, M. A.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5919924/
https://www.ncbi.nlm.nih.gov/pubmed/29700362
http://dx.doi.org/10.1038/s41598-018-25028-0
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author Wallace, M. K.
LaBarre, P. G.
Li, Jun
Pi, S.-T.
Pickett, W. E.
Dessau, D. S.
Haskel, D.
Ramirez, A. P.
Subramanian, M. A.
author_facet Wallace, M. K.
LaBarre, P. G.
Li, Jun
Pi, S.-T.
Pickett, W. E.
Dessau, D. S.
Haskel, D.
Ramirez, A. P.
Subramanian, M. A.
author_sort Wallace, M. K.
collection PubMed
description Compounds with honeycomb structures occupied by strong spin orbit coupled (SOC) moments are considered to be candidate Kitaev quantum spin liquids. Here we present the first example of Os on a honeycomb structure, Li(2.15(3))Os(0.85(3))O(3) (C2/c, a = 5.09 Å, b = 8.81 Å, c = 9.83 Å, β = 99.3°). Neutron diffraction shows large site disorder in the honeycomb layer and X-ray absorption spectroscopy indicates a valence state of Os (4.7 ± 0.2), consistent with the nominal concentration. We observe a transport band gap of Δ = 243 ± 23 meV, a large van Vleck susceptibility, and an effective moment of 0.85 μ(B), much lower than expected from 70% Os(+5). No evidence of long range order is found above 0.10 K but a spin glass-like peak in ac-susceptibility is observed at 0.5 K. The specific heat displays an impurity spin contribution in addition to a power law ∝T((0.63±0.06)). Applied density functional theory (DFT) leads to a reduced moment, suggesting incipient itineracy of the valence electrons, and finding evidence that Li over stoichiometry leads to Os(4+)−Os(5+) mixed valence. This local picture is discussed in light of the site disorder and a possible underlying quantum spin liquid state.
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spelling pubmed-59199242018-05-01 Local Moment Instability of Os in Honeycomb Li(2.15)Os(0.85)O(3) Wallace, M. K. LaBarre, P. G. Li, Jun Pi, S.-T. Pickett, W. E. Dessau, D. S. Haskel, D. Ramirez, A. P. Subramanian, M. A. Sci Rep Article Compounds with honeycomb structures occupied by strong spin orbit coupled (SOC) moments are considered to be candidate Kitaev quantum spin liquids. Here we present the first example of Os on a honeycomb structure, Li(2.15(3))Os(0.85(3))O(3) (C2/c, a = 5.09 Å, b = 8.81 Å, c = 9.83 Å, β = 99.3°). Neutron diffraction shows large site disorder in the honeycomb layer and X-ray absorption spectroscopy indicates a valence state of Os (4.7 ± 0.2), consistent with the nominal concentration. We observe a transport band gap of Δ = 243 ± 23 meV, a large van Vleck susceptibility, and an effective moment of 0.85 μ(B), much lower than expected from 70% Os(+5). No evidence of long range order is found above 0.10 K but a spin glass-like peak in ac-susceptibility is observed at 0.5 K. The specific heat displays an impurity spin contribution in addition to a power law ∝T((0.63±0.06)). Applied density functional theory (DFT) leads to a reduced moment, suggesting incipient itineracy of the valence electrons, and finding evidence that Li over stoichiometry leads to Os(4+)−Os(5+) mixed valence. This local picture is discussed in light of the site disorder and a possible underlying quantum spin liquid state. Nature Publishing Group UK 2018-04-26 /pmc/articles/PMC5919924/ /pubmed/29700362 http://dx.doi.org/10.1038/s41598-018-25028-0 Text en © The Author(s) 2018 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
spellingShingle Article
Wallace, M. K.
LaBarre, P. G.
Li, Jun
Pi, S.-T.
Pickett, W. E.
Dessau, D. S.
Haskel, D.
Ramirez, A. P.
Subramanian, M. A.
Local Moment Instability of Os in Honeycomb Li(2.15)Os(0.85)O(3)
title Local Moment Instability of Os in Honeycomb Li(2.15)Os(0.85)O(3)
title_full Local Moment Instability of Os in Honeycomb Li(2.15)Os(0.85)O(3)
title_fullStr Local Moment Instability of Os in Honeycomb Li(2.15)Os(0.85)O(3)
title_full_unstemmed Local Moment Instability of Os in Honeycomb Li(2.15)Os(0.85)O(3)
title_short Local Moment Instability of Os in Honeycomb Li(2.15)Os(0.85)O(3)
title_sort local moment instability of os in honeycomb li(2.15)os(0.85)o(3)
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5919924/
https://www.ncbi.nlm.nih.gov/pubmed/29700362
http://dx.doi.org/10.1038/s41598-018-25028-0
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