Gallium tracer diffusion and its isotope effect in germanium

Abstract The bulk diffusion of Ga in single crystals of Ge has been studied over a wide temperature range, 827-1189 K. The evaluation was performed using secondary-ion mass spectrometry (SIMS). The diffusion coefficients obtained ranged between the very low value of 9·6 × 10−23 and 1·5 × 10−16m2s−1. The results are expressed in the Arrhenius representation by the pre-exponential factor D0=(1·4±0·7) × 10−2 m2s−1 and the activation energy Q = 319·5±3·4kJmol−1. Secondary-ion mass spectrometry measurements also yielded the isotope effect of Ga in Ge, whose mean value was found to be E=0·240±0·045. This value is nearly equal to, or slightly lower than, the isotope effect of self-diffusion in Ge.