Investigation of a two-dimensional dysprosium germanide on Ge(111): A medium-energy ion-scattering study including direct observation of a reversal of top-layer buckling upon adsorption of hydrogen
Dj. Spence et al., Investigation of a two-dimensional dysprosium germanide on Ge(111): A medium-energy ion-scattering study including direct observation of a reversal of top-layer buckling upon adsorption of hydrogen, PHYS REV B, 62(8), 2000, pp. 5016-5020
A two-dimensional dysprosium germanide of stoichiometry DyGe2 on the Ge(111
) surface, with a nominal Dy coverage of one monolayer, has been investigat
ed using medium-energy ion scattering. A quantitative structural analysis h
as revealed that the Dy atoms reside beneath a well-ordered Ge(111) bilayer
, rotated by 180 degrees with respect to the bulk. Upon adsorption of hydro
gen, the buckling of the top layer was seen to reverse with a corresponding
expansion of the Dy-Ge bond length. Possible generalizations for other rar
e earth/semiconductor systems are discussed.