Quasielastic neutron scattering studies of H motion in Laves-phase compounds
Abstract
The results of our quasielastic neutron scattering measurements for a number of cubic Laves-phase hydrides AB2Hx are consistent with the coexistence of two types of H motion: the fast localized jumps within the hexagons formed by interstitial g (A2B2) sites and the slower hopping from one hexagon to another. The analysis of these results has revealed the relation between the hydrogen-hopping rates, the g-g distances, and the ratio of the metallic radii RA and RB of the elements A and B forming the AB2 compound. We conclude that the behavior of the two frequency scales of H motion is determined mainly by RA/RB. A new type of localized H motion is predicted for compounds with RA/RB>1.35.
- Publication:
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Applied Physics A: Materials Science & Processing
- Pub Date:
- 2002
- DOI:
- 10.1007/s003390201559
- Bibcode:
- 2002ApPhA..74S.948S
- Keywords:
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- PACS: 66.30.-h;
- 78.70.Nx