A calculation of the influence of isolated dislocations on self-diffusion measurements in F.C.C. metals at lower temperatures

Calculations are made of the influence of dislocations on self-diffusion measurements in f.c.c. metals at lower temperatures by a tracer sectioning technique, using a model of isolated dislocation pipes following Mimkes and Wuttig. It is found that under experimental circumstancesat lower temperatures the influence of a dislocation is restricted to a relatively small area around the pipe. If sectioning is performed until the activity of a stripped layer is 1/10 of the activity of the first layer, the influence on the penetration plot is scarcely perceptible for the case of a dislocation density of 106 to 107/cm2, these densities usually being found in well annealed f.c.c. single crystals. This outcome is not incompatible with experimental results.