A mechanism for self-diffusion and impurity diffusion in vanadium

Using a classical analysis of diffusion data in combination with results obtained from positron annihilation, Mössbauer spectroscopy and N.M.R. experiments, the change in slope of the Arrhenius curve reported to occur for diffusion in vanadium has been quantitatively interpreted in the cases of self-diffusion and Mn, Fe, Co, Ni and Cu impurity diffusion. It has been shown that three kinds of ‘point defects’ contribute to atomic transport: (i) free single vacancies whose efficiency culminates around 1200–1550°C; (ii) divacancies, especially in the high-temperature regime; (iii) interstitial impurity-vacancy complexes whose strongest influence is visible in the low-temperature range.