The rate of absorption of H was measured by using steady-state and unsteady-state gas-liquid metal diffusion cell techniques. The absorption process was considered to be diffusion-controlled. The data for temperatures ranging from 985 to 1208C fitted:

D (cm2/s) = 4.54 x 10-2 exp[-1.359(kcal/mol)/RT]

E.M.Sacris, N.A.D.Parlee: Metallurgical Transactions, 1970, 1[12], 3377-82

Table 7

Pipe Diffusivity of Ag Isotopes in Ag Polycrystals