Copper interface induced relaxation of TiO2(110)-1X1

Surface x-ray diffraction has been used to examine the effect of a Cu overl ayer on the bulk structural relaxations of TiO2(110) 1 x 1). The Ti atoms a t this buried interface are at close to their bulk-terminated positions, re presenting a derelaxation from the clean surface positions by up to about 0 .2 Angstrom. In contrast, O atom vertical and lateral displacements are enh anced, with values of up to 0.4 +/- 0.1 Angstrom and 0.6 +/- 0.1 Angstrom, respectively. This enhanced relaxation is consistent with Cu-O bonding.