The diffusivity of H in α-phase films was measured, at temperatures of between 278 and 323K, by using an electrochemical stripping method. The films were deposited onto Fe substrates by means of radio-frequency sputtering. The diffusion coefficients which were found for 0.00068 and 0.00136mm films were some 2 orders of magnitude lower than the values reported for bulk specimens. The results could be described by the expression:
D (m2/s) = 4.16 x 10-9exp[-25.7(kJ/mol)/RT]
Diffusion Coefficient of Hydrogen in Palladium Films Prepared by RF Sputtering. H.Hagi: Journal of the Japan Institute of Metals, 1989, 53[11], 1085-8. See also: Materials Transactions, 1990, 31[11], 954-8
Table 129
Diffusivity of H through Pd Membranes
with Various Surface Treatments
H/Pd | Temperature (K) | Treatment | D (cm2/s) |
0.015 | 423 | oxidized, 122 | 6.14 x 10-6 |
0.020 | 423 | oxidized, 122μ | 6.08 x 10-6 |
0.020 | 423 | palladized, 104μ | 6.11 x 10-6 |
0.020 | 423 | polished, 119μ | 5.24 x 10-6 |
0.025 | 423 | oxidized, 122μ | 6.03 x 10-6 |
0.025 | 423 | palladized, 104μ | 6.10 x 10-6 |
0.025 | 423 | polished, 119μ | 5.28 x 10-6 |
0.030 | 423 | oxidized, 122μ | 5.96 x 10-6 |
0.030 | 423 | palladized, 104μ | 5.95 x 10-6 |
0.030 | 423 | polished, 119μ | 5.15 x 10-6 |
0.035 | 423 | oxidized, 122μ | 5.69 x 10-6 |
0.035 | 423 | palladized, 104μ | 5.72 x 10-6 |
0.035 | 423 | polished, 119μ | 4.91 x 10-6 |
0.040 | 423 | oxidized, 122μ | 5.49 x 10-6 |
0.040 | 423 | palladized, 104μ | 5.54 x 10-6 |
0.040 | 423 | polished, 119μ | 4.85 x 10-6 |
0.045 | 423 | oxidized, 122μ | 5.33 x 10-6 |
0.010 | 473 | oxidized, 122μ | 1.31 x 10-5 |
0.015 | 473 | oxidized, 122μ | 1.28 x 10-5 |
continued
Table 129 (continued)
Diffusivity of H through Pd Membranes
with Various Surface Treatments
H/Pd | Temperature (K) | Treatment | D (cm2/s) |
0.015 | 473 | palladized, 104μ | 1.34 x 10-5 |
0.015 | 473 | polished, 119μ | 1.15 x 10-5 |
0.020 | 473 | oxidized, 122μ | 1.28 x 10-5 |
0.020 | 473 | palladized, 104μ | 1.33 x 10-5 |
0.020 | 473 | polished, 119μ | 1.15 x 10-5 |
0.025 | 473 | oxidized, 122μ | 1.26 x 10-5 |
0.025 | 473 | palladized, 104μ | 1.33 x 10-5 |
0.025 | 473 | polished, 119μ | 1.13 x 10-5 |
0.010 | 523 | oxidized, 122μ | 2.29 x 10-5 |
0.010 | 523 | palladized, 104μ | 2.35 x 10-5 |
0.010 | 523 | polished, 119μ | 2.06 x 10-5 |
0.015 | 523 | oxidized, 122μ | 2.29 x 10-5 |
0.015 | 523 | palladized, 104μ | 2.34 x 10-5 |
0.015 | 523 | polished, 119μ | 2.05 x 10-5 |
0.020 | 523 | oxidized, 122μ | 2.29 x 10-5 |
0.020 | 523 | palladized, 104μ | 2.32 x 10-5 |
0.020 | 523 | polished, 119μ | 2.05 x 10-5 |
0.025 | 523 | oxidized, 122μ | 2.29 x 10-5 |
0.025 | 523 | palladized, 104μ | 2.32 x 10-5 |
0.025 | 523 | polished, 119μ | 2.03 x 10-5 |