The study on the state of hydrogen dissolved in metals by means of the channelling method

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/mm2, the H atoms are displaced from T sites by about 0.44 A 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 0.6 A towards the nearest neighbour lattice points at room temperature and become located at the T sites at 373 K, 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. (author)