Experiments were carried out by using couples between pure Zr and dilute binary alloys which contained Ag. The impurity diffusion coefficients were determined by using Darken’s relationship. It was found that the experimental results supported the occurrence of a size effect for impurity diffusion in -Zr and -Zr. The temperature ranges used were relatively narrow (1173 to 1290K for -Zr, 1028 to 1104K for -Zr), and the results could be described by:

:     D (cm2/s) = 1.7 x 10-2exp[-48.6(kcal/mol)/RT]

:     D (cm2/s) = 2.5 x 10-4exp[-30.5(kcal/mol)/RT]

Y.Iijima, O.Taguchi: Journal of Materials Science Letters, 1995, 14[7], 486-9