Secondary ion mass spectrometry was used to measure diffusion profiles in monocrystalline specimens of nominally pure α-phase (with about 50ppm), or polycrystalline (1-2mm) samples of ultra-pure material (less than 1ppm) and Fe-doped material (50ppm). The results for ultra-pure material could be described by:

D (m2/s) = 2.6 x 10-5exp[-3.1(eV)/kT]

On the basis of the results (tables 93 and 94), it was concluded that intrinsic substitutional diffusion was normal, and that Fe was responsible for the enhanced substitutional diffusion which was observed in nominally pure Zr.

G.M.Hood, H.Zou, R.J.Schultz, J.A.Roy, J.A.Jackman: Journal of Nuclear Materials, 1992, 189[2], 226-30