TY - JOUR
T1 - Structure of the self-interstitial in diamond
AU - Smith, H E
AU - Davies, G
AU - Newton, M E
AU - Kanda, H
PY - 2004/1
Y1 - 2004/1
N2 - We report on a study of the structure of the neutral self-interstitial I-0 in diamond, through the use of uniaxial stress measurements and isotope-substitution effects on the optical absorption lines near 1685 and 1859 meV. The stress perturbations are explicable in terms of a center with D-2d symmetry, and the dominant stress-induced perturbations are found to be interactions between the states of the center. The interstate couplings establish that the excited electronic state of the transitions is a doublet, of 5.0+/-0.1 meV splitting, revealing the existence of another electronic state at I-0 that has not been discussed within existing models of the center. The excited-state doublet couples through B-2 deformations, while the well-known ground-state doublet, whose splitting is measured spectroscopically at 7.6+/-0.1 meV, is coupled by B-1 deformations of the center. The data are quantitatively consistent with I-0, in its ground electronic state, tunneling rapidly in a B-1 vibrational mode between equivalent D-2-symmetry configurations, and in its excited electronic state tunneling in a B-2 mode between equivalent C-2v-symmetry configurations; in both cases, the motion is sufficiently rapid for I-0 to have the observed effective D-2d point group.
AB - We report on a study of the structure of the neutral self-interstitial I-0 in diamond, through the use of uniaxial stress measurements and isotope-substitution effects on the optical absorption lines near 1685 and 1859 meV. The stress perturbations are explicable in terms of a center with D-2d symmetry, and the dominant stress-induced perturbations are found to be interactions between the states of the center. The interstate couplings establish that the excited electronic state of the transitions is a doublet, of 5.0+/-0.1 meV splitting, revealing the existence of another electronic state at I-0 that has not been discussed within existing models of the center. The excited-state doublet couples through B-2 deformations, while the well-known ground-state doublet, whose splitting is measured spectroscopically at 7.6+/-0.1 meV, is coupled by B-1 deformations of the center. The data are quantitatively consistent with I-0, in its ground electronic state, tunneling rapidly in a B-1 vibrational mode between equivalent D-2-symmetry configurations, and in its excited electronic state tunneling in a B-2 mode between equivalent C-2v-symmetry configurations; in both cases, the motion is sufficiently rapid for I-0 to have the observed effective D-2d point group.
UR - http://www.scopus.com/inward/record.url?scp=1542411661&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.69.045203
DO - 10.1103/PhysRevB.69.045203
M3 - Article
SN - 1550-235X
SN - 2469-9969
VL - 69
SP - 452031
EP - 452039
JO - Physical Review B (Condensed Matter and Materials Physics)
JF - Physical Review B (Condensed Matter and Materials Physics)
IS - 4
M1 - 045203
ER -