Abstract
The local adsorption structure of the coadsorption phase of K and CO on Co(0001) has been determined at 160 K using dynamical low-energy electron diffraction. The K atoms in the overlayer adopt the on-top sites as in the -K structure, but the bond length to the nearest Co atom increases by 0.2 Å to The CO molecules are shifted from the on-top sites of the -CO structure to the fcc and hcp three-fold hollow sites. The axis of the CO molecule is perpendicular to the surface. The adsorption induce buckling in the top Co layer, pushing the Co atom beneath the K by towards the bulk. The optimum length for the C-O bond is and that for the C-Co bond The obtained structure is compared to other known CO+K coadsorption structures on transition metals, as well as to the -CO and -K structures on Co(0001).
- Received 20 October 2000
DOI:https://doi.org/10.1103/PhysRevB.63.155402
©2001 American Physical Society