Goss, J. P., Ewels, C. P., Briddon, P. R. & Fritsch, E. (2011) Bistable N(2)-H complexes: The first proposed structure of a H-related colour-causing defect in diamond. Diam. Relat. Mat. 20 896–901.
Added by: Laurent Cournède (2016-03-10 21:32:20)
|Type de référence: Article
Numéro d'identification (ISBN etc.): 0925-9635
Clé BibTeX: Goss2011
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Mots-clés: ab-initio, boron-doped diamond, Chameleon, chameleon diamonds, Conductivity, dft, diamond, elastic band method, hydrogen, hydrogen complex, Infrared, minimum energy paths, n-type diamond, nitrogen, saddle-points, Semiconductor
Créateurs: Briddon, Ewels, Fritsch, Goss
Collection: Diam. Relat. Mat.
Consultations : 3/439
Indice de consultation : 2%
Indice de popularité : 0.5%
We examine the hydrogenated substitutional nitrogen pair defect, N(2)-H, in diamond, with different charge states using density functional theory calculations. Neutral N(2)-H is predicted to exhibit optical absorption in the 600 nm to near infrared range, hence contributing to colour. We suggest that it may be representative of a family of nitrogen-hydrogen complexes, which due to covalent nitrogen-hydrogen bonding could explain several observed absorptions. Changing the charge state leads to spontaneous geometric rearrangements, and we find the neutral charge state is thermodynamically metastable. The resultant negative-U behaviour suggests it is unstable as a donor. The structural changes with charge state may contribute to the thermochromic and photochromic behaviour of the so-called "chameleon" diamonds. (C) 2011 Elsevier B.V. All rights reserved.
Added by: Laurent Cournède