Direct experimental evidence for dipolar interactions within the 2-dimensional Pb defect system at the interface was provided by observations of an anisotropy in the electron spin resonance spectra. This was made possible by means of careful interface degradation via post-oxidation annealing in H2. This led to an increased Pb density. The results were interpreted in terms of a computational model which was based upon a magnetostatic approximation to the local field. The results suggested that Pb defects exhibited a self-avoiding behaviour, and confirmed their occurrence to be related to the release of interface stresses.

Dipolar Interactions between Unpaired Si Bonds at the (111)Si/SiO2 Interface. A.Stesmans, B.Nouwen: Materials Science and Engineering B, 1999, 58[1-2], 52-5