J. Hayoz et al., OBSERVATION OF THE REVERSIBLE H-INDUCED STRUCTURAL TRANSITION IN THINY-FILMS VIA X-RAY PHOTOELECTRON DIFFRACTION, Physical review. B, Condensed matter, 58(8), 1998, pp. 4270-4273
Yttrium can be loaded with hydrogen up to high concentrations causing
dramatic structural and electronic changes of the host lattice. We rep
ort on the reversibility of hydrogen loading in thin single-crystallin
e Y films grown by vapor deposition on W(110). Under a H-2 partial pre
ssure of 1x10(-5) mbar the hexagonal-closed-packed Y films convert to
the face-centered-cubic Y dihydride. Unloading is accomplished by anne
aling the dihydride to 1000 K. No loss of crystallinity is observed du
ring these martensitic transformations of the Y lattice. Moreover, we
demonstrate a model to determine the H concentration in Y in situ.