PARAMAGNETIC STRUCTURE OF THE SOLITON OF THE 30-DEGREES PARTIAL DISLOCATION IN SILICON

Based on ab initio calculations, we propose a new structure for the fu ndamental excitation of the reconstructed 30 degrees partial dislocati on in silicon. This soliton has a rare structure involving a fivefold coordinated atom near the dislocation con. The unique electronic struc ture of this defect is consistent with the electron spin resonance sig nature of the hitherto enigmatic thermally stable R center of plastica lly deformed silicon. This identification suggests the possibility of an experimental determination of the density of solitons, a key defect in understanding the plastic flow of the material.