The diffusivity in the core of boundary regions was deduced from changes in the intensity of the radiation that was emitted by atomic probes, as a function of the annealing time and temperature. The Arrhenius relationship which characterized the temperature dependence of 57Cd diffusion in the core of the so-called crystallite conjugation regions of polycrystalline W was found to be described by:

D (cm2/s) = 2.5 x 10-6exp[-132.9(kJ/mol)/RT]

S.M.Klotsman, M.I.Kurkin, V.N.Kaigorodov, V.V.Dyakin, M.S.Dudarev: Physics of Metals and Metallography, 1996, 82[1], 67-70

The best linear fits to the solute diffusion data ([5] to [25]) yield:

H (sd): Ln[Do] = 1.49E – 21 (R2 = 0.87); W(sd): Ln[Do] = 0.33E – 16.1 (R2 = 0.63)