The diffusion coefficients in the core of boundary regions were 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:

D (m2/s) = 2.5 x 10-10exp[-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