Mass spectrometric measurements of isotope fractionation of interstitial Li in rutile were made which indicated, within experimental error, agreement with the expected M-1/2 dependence of the diffusion coefficient, D. The major source of error apparently was the variation of D due to inhomogeneities in the specimen.

Isotopic Mass Dependence of Li Diffusion in Rutile. Johnson, O.W., Krouse, H.R.: Journal of Applied Physics, 1966, 37[2], 668-70