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Wagner, P., Ewels, C. P., Suarez-Martinez, I., Guiot, V., Cox, S. F. J., Lord, J. S. & Briddon, P. R. (2011) Behavior of hydrogen ions, atoms, and molecules in alpha-boron studied using density functional calculations. Phys. Rev. B, 83 024101.
Added by: Laurent Cournède (2016-03-10 21:32:21) |
| Type de référence: Article DOI: 10.1103/PhysRevB.83.024101 Numéro d'identification (ISBN etc.): 1098-0121 Clé BibTeX: Wagner2011a Voir tous les détails bibliographiques  |
Catégories: PMN Mots-clés: hydrides, icosahedral clusters, nanotubes, orbitals, Pressure, Stability Créateurs: Briddon, Cox, Ewels, Guiot, Lord, Suarez-Martinez, Wagner Collection: Phys. Rev. B |
Consultations : 6/492
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| Résumé |
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We examine the behavior of hydrogen ions, atoms, and molecules in alpha-boron using density functional calculations. Hydrogen behaves as a negative-U center, with positive H ions preferring to sit off-center on interlayer bonds and negative H ions sitting preferably at in-plane sites between three B(12) icosahedra. Hydrogen atoms inside B(12) icosahedral cages are unstable, drifting off-center and leaving the cage with only a 0.09 eV barrier. While H(0) is extremely mobile (diffusion barrier 0.25 eV), H(+) and H(-) have higher diffusion barriers of 0.9 eV. Once mobile, these defects will combine, forming H(2) in the interstitial void space, which will remain trapped in the lattice until high temperatures. Based on these results we discuss potential differences for hydrogen behavior in beta-boron and compare with experimental muon-implantation data.
Added by: Laurent Cournède |