Membranes of Marz-grade material were prepared by rolling to a thickness of 0.109mm and annealing (1273K, 20h) in vacuum. The diffusivity was then measured by using an electrolytic double-cell method. It was found that the results (table 68) could be described by:

D (m2/s) = 9.271 x 10-8 exp[-23.28(kJ/mol)/RT]

It was concluded that the simple classical model for H diffusion was sufficient to explain diffusion in this material at temperatures of between 280 and 1690K.

P.Sutter, R.B.McLellan: Scripta Metallurgica, 1985, 19[7], 879-80

 

Table 68

Diffusivity of H in Co

 

Temperature (K)

D (m2/s)

278.4

3.382 x 10-12

287.1

6.613 x 10-12

290.2

5.457 x 10-12

293.8

9.281 x 10-12

294.7

1.075 x 10-11

317.5

1.239 x 10-11

317.6

1.289 x 10-11

319.4

8.136 x 10-12

324.2

1.910 x 10-11

332.2

1.816 x 10-11