It was found that a preferential alignment of the NL8 thermal double-donors was produced when an uniaxial stress was applied during their formation at about 450C. The recovery kinetics revealed that they could reorient themselves easily at the time-scale of their own lifetime, and that their individual alignments therefore reflected the strain fields that each of them introduced into the lattice. Further analysis revealed that each of the donor cores produced a large compressional strain along its C2v [001]’ axis. The magnitude of the latter decreased monotonically with progression in the series of thermal double-donors species. This suggested that strain relief was the mechanism that was responsible for nearby O accumulation. The rate of, and activation energy for, reorientation suggested that the process was limited by diffusional motion of the nearby interstitial O atoms. Here, some 5 jumps were required for TDD3 (the third in the series); with more and more being required for subsequent ones.

J.M.Trombetta, G.D.Watkins, J.Hage, P.Wagner: Journal of Applied Physics, 1997, 81[3], 1109-15