The diffusion of Al in α-Hf was studied at 973 to 1298K by using the nuclear resonance technique. The measurements show that the diffusion coefficient exhibited Arrhenius behavior,

D (m2/s) = 3 x 10-4 exp[-337(kJ/mol)/RT]

The activation energy was typical of a substitutional mechanism of diffusion, as could be deduced from self-diffusion measurements. On the other hand, differences between the present and previous published results could be attributed to the different purity of the samples used in each experiment.

F.Bernardi, M.Behar, J.H.R.dos Santos, F.Dyment: Applied Physics A, 2005, 80[1], 69-72

Table 116

Activation Energy for H Diffusion in HfHx