Self-diffusion in chromium

Self-diffusion in chromium single crystals has been measured over the temperature range 1073 to 1446 K. These data, when combined with earlier measurements from this laboratory over the range 1370-2090 K, yield a plot of $\ln D$ vs $\frac{1}{T}$, which is straight over ten orders of magnitude in the diffusion coefficient $D$. The high values of the preexponential factor (1280±230 ${\mathrm{cm}}^2$ ${\mathrm{s}}^{-1\mathrm{}}$) and activation enthalpy (4.58±0.03 eV) are not readily interpreted in terms of a specific diffusion mechanism. They appear to be too high to be interpreted in terms of a monovacancy mechanism. The possible contribution of divacancies and self-interstitials are discussed.