hyperfine structure of the interface defect in thermal

The observation of the electron spin resonance hyperfine (hf) spectra associated with the unpaired electron of the interface defect in thermal shows that the dominant interaction arises from a single 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 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 with the [100] interface normal. With oxygen not constituting an immediate part of the defect, the results firmly establish the key part of the defect as a tilted ( about ) unit.