The diffusion of T was studied by using time-lag techniques. The β-radiation which originated from T decay within a thin layer near to the external surface was used to monitor changes in T concentration with time in this layer. No passage of T atoms through the phase boundary was necessary, and no energy barriers which might retard their passage could therefore interfere. The results for Ta at 25C indicated a diffusivity of 5 x 10-7cm2/s.

G.Sicking, H.Buchold: Zeitschrift für Naturforschung A, 1971, 26[12], 1973-80

Table 165

Heat of Transport of H and D in Ta