A study was made of recombination-enhanced Fe atom jumps between the first- and second-nearest neighbor sites of Fe-Al and Fe-B pairs. Specimens were first annealed at 80C in order to generate Fe acceptor pairs after Fe doping. The concentrations of the first- and second-nearest neighbor Fe-acceptor pairs were determined by performing electron spin resonance measurements after annealing at about 150K under optical excitation. It was found that the concentration of the first-nearest neighbor pairs decreased, while that of the second-nearest neighbor pairs increased, during annealing. The activation energy for the above changes was equal to about 0.11eV in the case of Fe-Al pairs. This was much smaller than that (0.8eV) for thermal annealing alone. In the case of Fe-B pairs, the electron spin resonance signals from the second-nearest-neighbor pairs could be detected due to annealing at about 160K under optical excitation.

S.Sakauchi, M.Suezawa, K.Sumino, H.Nakashima: Journal of Applied Physics, 1996, 80[11], 6198-203