A molecular radical model for hydrogen and muonium in graphite

S F J Cox, S P Cottrell, M Charlton, P A Donnelly, C Ewels, M Heggie, B Hourahine

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

Detection of muon spin relaxation in graphite above room temperature, together with reports of a temperature-dependent muon Knight shift, suggest that the muon state in graphite is not electronically diamagnetic, as previously supposed. The involvement of a molecular radical formed by the chemical reaction and bonding of interstitial muonium is proposed. These considerations should, with due regard for isotope effects, apply similarly to hydrogen and are supported by simulations of hydrogen addition to a graphene fragment. Density functional calculations provide hyperfine parameters as well as a visualization of the singly occupied molecular orbital. This allows interpretation of the data in terms of the temperature-dependent occupancy of this orbital and its rate of exchange with conduction electrons.
LanguageEnglish
Pages2169-2175
Number of pages7
JournalJournal of Physics: Condensed Matter
Volume13
Issue number10
DOIs
Publication statusPublished - 2001

Fingerprint

muonium
Graphite
Hydrogen
muons
graphite
hydrogen
Molecular orbitals
Isotopes
conduction electrons
isotope effect
Temperature
Graphene
Density functional theory
Chemical reactions
chemical reactions
molecular orbitals
graphene
interstitials
Visualization
fragments

Cite this

Cox, S. F. J., Cottrell, S. P., Charlton, M., Donnelly, P. A., Ewels, C., Heggie, M., & Hourahine, B. (2001). A molecular radical model for hydrogen and muonium in graphite. Journal of Physics: Condensed Matter, 13(10), 2169-2175. https://doi.org/10.1088/0953-8984/13/10/312
Cox, S F J ; Cottrell, S P ; Charlton, M ; Donnelly, P A ; Ewels, C ; Heggie, M ; Hourahine, B. / A molecular radical model for hydrogen and muonium in graphite. In: Journal of Physics: Condensed Matter. 2001 ; Vol. 13, No. 10. pp. 2169-2175.
@article{b319209703bb4ca4960eff0619aa9789,
title = "A molecular radical model for hydrogen and muonium in graphite",
abstract = "Detection of muon spin relaxation in graphite above room temperature, together with reports of a temperature-dependent muon Knight shift, suggest that the muon state in graphite is not electronically diamagnetic, as previously supposed. The involvement of a molecular radical formed by the chemical reaction and bonding of interstitial muonium is proposed. These considerations should, with due regard for isotope effects, apply similarly to hydrogen and are supported by simulations of hydrogen addition to a graphene fragment. Density functional calculations provide hyperfine parameters as well as a visualization of the singly occupied molecular orbital. This allows interpretation of the data in terms of the temperature-dependent occupancy of this orbital and its rate of exchange with conduction electrons.",
author = "Cox, {S F J} and Cottrell, {S P} and M Charlton and Donnelly, {P A} and C Ewels and M Heggie and B Hourahine",
year = "2001",
doi = "10.1088/0953-8984/13/10/312",
language = "English",
volume = "13",
pages = "2169--2175",
journal = "Journal of Physics: Condensed Matter",
issn = "0953-8984",
number = "10",

}

Cox, SFJ, Cottrell, SP, Charlton, M, Donnelly, PA, Ewels, C, Heggie, M & Hourahine, B 2001, 'A molecular radical model for hydrogen and muonium in graphite' Journal of Physics: Condensed Matter, vol. 13, no. 10, pp. 2169-2175. https://doi.org/10.1088/0953-8984/13/10/312

A molecular radical model for hydrogen and muonium in graphite. / Cox, S F J; Cottrell, S P; Charlton, M; Donnelly, P A; Ewels, C; Heggie, M; Hourahine, B.

In: Journal of Physics: Condensed Matter, Vol. 13, No. 10, 2001, p. 2169-2175.

Research output: Contribution to journalArticle

TY - JOUR

T1 - A molecular radical model for hydrogen and muonium in graphite

AU - Cox, S F J

AU - Cottrell, S P

AU - Charlton, M

AU - Donnelly, P A

AU - Ewels, C

AU - Heggie, M

AU - Hourahine, B

PY - 2001

Y1 - 2001

N2 - Detection of muon spin relaxation in graphite above room temperature, together with reports of a temperature-dependent muon Knight shift, suggest that the muon state in graphite is not electronically diamagnetic, as previously supposed. The involvement of a molecular radical formed by the chemical reaction and bonding of interstitial muonium is proposed. These considerations should, with due regard for isotope effects, apply similarly to hydrogen and are supported by simulations of hydrogen addition to a graphene fragment. Density functional calculations provide hyperfine parameters as well as a visualization of the singly occupied molecular orbital. This allows interpretation of the data in terms of the temperature-dependent occupancy of this orbital and its rate of exchange with conduction electrons.

AB - Detection of muon spin relaxation in graphite above room temperature, together with reports of a temperature-dependent muon Knight shift, suggest that the muon state in graphite is not electronically diamagnetic, as previously supposed. The involvement of a molecular radical formed by the chemical reaction and bonding of interstitial muonium is proposed. These considerations should, with due regard for isotope effects, apply similarly to hydrogen and are supported by simulations of hydrogen addition to a graphene fragment. Density functional calculations provide hyperfine parameters as well as a visualization of the singly occupied molecular orbital. This allows interpretation of the data in terms of the temperature-dependent occupancy of this orbital and its rate of exchange with conduction electrons.

U2 - 10.1088/0953-8984/13/10/312

DO - 10.1088/0953-8984/13/10/312

M3 - Article

VL - 13

SP - 2169

EP - 2175

JO - Journal of Physics: Condensed Matter

T2 - Journal of Physics: Condensed Matter

JF - Journal of Physics: Condensed Matter

SN - 0953-8984

IS - 10

ER -

Cox SFJ, Cottrell SP, Charlton M, Donnelly PA, Ewels C, Heggie M et al. A molecular radical model for hydrogen and muonium in graphite. Journal of Physics: Condensed Matter. 2001;13(10):2169-2175. https://doi.org/10.1088/0953-8984/13/10/312