A new structure for the fundamental excitation of the reconstructed 30° partial dislocation was proposed on the basis of ab initio calculations. This soliton had a rare structure which involved a 5-fold coordinated atom near to the dislocation core. The unique electronic structure of this defect was consistent with the electron spin resonance signature of the previously puzzling thermally stable R centre of plastically deformed Si. A first ab initio determination of the free energy of the soliton was presented which was also in agreement with experimental observations. This suggested the possibility of the experimental determination of the density of solitons.

New Physics of the 30° Partial Dislocation in Silicon Revealed through ab initio Calculation. G.Csányi, T.D.Engeness, S.Ismail-Beigi, T.A.Arias: Journal of Physics - Condensed Matter, 2000, 12[49], 10029-37