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.