Reversible loading of epitaxial Y(00.1) films with hydrogen
Abstract
Yttrium can be loaded with hydrogen up to high concentrations causing dramatic structural and electronic changes of the host lattice. We report on the reversibility of hydrogen loading in thin, monocrystalline Y-films grown by MBE on Nb/Al_2O3 substrates. During hydrogen loading, the Yttrium film undergoes structural transitions from the cubic dihydride to the hexagonal trihydride phase, while the structural coherence and the in-plane epitaxial relation to the Nb buffer layer is maintained. The transition from YH2 to YH3 occurs at room temperature at a hydrogen pressure of 10 mbar and is completely reversible. Reversibility is also observed for deuteration of Y. However, the kinetics is more sluggish. Although the YH2 structure is chemically stable, isotope exchange with deuterium takes place rapidly. (A. Remhof, G. Song, K. Theis-Bröhl, H. Zabel, Phys. Rev. B 56) R2897 (1997)
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 1998
- Bibcode:
- 1998APS..MAR.X2307R