Small-angle neutron scattering was used to characterize D-trapping at dislocations in deformed single crystals during in situ gas-evolution experiments. Cold-rolling and hydride cycling treatments created differing dislocation arrangements or sub-structures. A reduction in the trapped D concentration at dislocations during evolution was monitored directly by means of small-angle neutron scattering. Exponential decay rates of the trapped concentration were observed in both types of sample; as expected for a bulk diffusion process which was modified by dislocation-trapping interactions. The reduction in D concentration was 1.2 to 1.4 times faster in cold-rolled material than in hydride-cycled material. This was attributed to the presence of a smaller number of dislocation trapping-sites in the cold-rolled material. The binding energy of D at dislocations was deduced by using a diffusion-based model. A binding energy of 0.20eV was found to characterize the trapping interaction in both cold-rolled and hydride-cycled material.

Effect of Dislocation Trapping on Deuterium Diffusion in Deformed, Single-Crystal Pd. B.J.Heuser, J.S.King: Metallurgical and Materials Transactions A, 1998, 29[6], 1593-8