The thermotransport of the isotopes in V-based alloys was found to be slower than that in pure V. The addition of V to Nb also increased the thermotransport of D and H, with respect to that in pure Nb. The heat of transport was positive, and was markedly greater for D than for H (table 185). It was concluded that the results were consistent with an atomistic model in which the temperature-dependence of the atomic jump frequencies was the predominant factor. There was a small bias in the direction of the atomic jumps. It was proposed that the differences between the heats of transport, for H and D, were related to an isotope-effect in the activation energy for diffusion.
D.T.Peterson, M.F.Smith: Metallurgical Transactions A, 1983, 14[5], 871-4
Table 185
Thermotransport of D and H in V
Material | Migrating Species | H (kJ/mol) |
Nb | H | 9.4 |
Nb | D | 16.3 |
V | H | 1.8 |
V | D | 6.1 |
V-10at%Cr | H | 4.8 |
V-10at%Cr | D | 9.2 |
V-20at%Cr | H | 5.8 |
V-20at%Cr | D | 10.0 |
V-10at%Nb | H | 8.5 |
V-10at%Nb | D | 12.5 |
V-25at%Nb | H | 13.1 |
V-25at%Nb | D | 16.5 |
V-50at%Nb | H | 15.8 |
V-50at%Nb | D | 18.8 |
V-75at%Nb | H | 16.9 |
V-75at%Nb | D | 20.0 |
V-90at%Nb | H | 15.8 |
V-90at%Nb | D | 20.4 |
V-1at%Ti | H | 3.5 |
V-1at%Ti | D | 7.6 |
V-5at%TI | H | 7.7 |
V-5at%Ti | D | 10.9 |
V-10at%Ti | H | 10.4 |
V-10at%Ti | D | 13.4 |
V-20at%Ti | H | 12.2 |
V-20at%Ti | D | 14.2 |
V-30at%Ti | H | 12.1 |
V-30at%Ti | D | 13.2 |