Journal of physics-condensed matter vol:10 issue:27 pages:L465-L472
The observation of the electron spin resonance hyperfine (hf) spectra associated with the unpaired electron of the For interface defect in thermal (100)Si/SiO2 shows that the dominant interaction arises from a single Si-29 isotope. The hf tensor displays weakly monoclinic I (nearly axial) symmetry, with the principal axes of the g and hf tensors coinciding. A molecular orbital analysis indicates that the unpaired electron resides for similar to 58% in a single unpaired Si hybrid orbital, found to be 14% s-like and 86% p-like, with the p-orbital markedly pointing closely along a  direction at 35.26 degrees with the  interface normal. With oxygen not constituting an immediate part of the defect, the results firmly establish the key part of the P-b1 defect as a tilted (similar to 20 degrees about ) Si-3=Si unit.