Adsorbate-Promoted Tunneling-Electron-Induced Local Faceting of D/Pd{110}-(1x2)

We have utilized tunneling electrons and thiophene adsorption to draw deuterium (D) from within the single-crystal bulk beneath Pd{110} up to subsurface adsorption sites. We found local faceting induced by this process, and determined the energy threshold of drawing bulk D to subsurface sites to be 0.38 +/- 0.02 eV. We show that these facets propagate along the < 1 (1) over bar0 > direction of the substrate, and that Pd{110) adopts the (1 x 1) surface reconstruction on the induced facets, yet maintains the paired row (1 x 2) structure on unaffected regions. After producing subsurface D, the facet plane tilts 3.2 +/- 0.8 degrees off the substrate plane.