The 1H(15N, )12C nuclear reaction was used to measure H profiles in anodically oxidized specimens which contained various amounts of Nb. The profiles were correlated with O profiles that had been obtained by using a scanning Auger microprobe, and with X-ray diffraction patterns. Non-oxidized Zr-2.5wt%Nb samples were also implanted with O and H in order to study the interaction between these 2 species. It was found that all of the anodically oxidized specimens, except pure Zr and single-phase Zr-20wt%Nb, exhibited H peaks beneath the oxide layer. These results indicated that the H migrated to the sub-oxide region, under the influence of a stress gradient, where the metal lattice was expanded by the surface oxide growth. The results showed that dissolved O sites in the Zr-2.5Nb alloy did not trap H.

D.Khatamian: Journal of Alloys and Compounds, 1995, 231, 722-9