The pressure dependence of the diffusivity of the transition element was studied by using the radio-tracer method, with serial sectioning by microtome. Diffusion annealing was carried out under Ar pressures of up to 0.8GPa. The activation volumes for diffusion were determined by isothermal annealing, giving:

D (cm2/s) = 1.93 x 102 exp[-40.1(kcal/mol)/RT]

G.Rummel, T.Zumkley, M.Eggersmann, K.Freitag, H.Mehrer: Zeitschrift für Metallkunde, 1995, 86[2], 131-40