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