The lattice locations of hydrogen dissolved in V, Nb, Ta and Nb-Mo alloys are investigated by the channelling method utilizing a nuclear reaction
1H(
11B, α) αα with a
11B beam. The H atoms are located at tetrahedral (
T) sites in V, Nb and Ta. In V, under the [001] compressive stress of 7 kg/mm
2, the H atoms are displaced from
T sites by about 0.44Å towards octahedral (
O) sites, and after the release of the stress they return to the
T sites. In Nb-3 at%Mo alloys the H atoms are located at the sites displaced from the
T sites by about 0.6Å towards the nearest neighbour lattice points at room temperature and become located at the
T sites at 373K, indicating the trapping of H by Mo atoms at room temperature. With increasing Mo concentration, the fraction of the H atoms located at the trapped sites decreases, and most of them are located at the
T sites and some portion of them are at the
O sites.
View full abstract