The molecular adsorption of CO on the Ru(1 1 2̄ 0) surface

The molecular adsorption of CO was studied on the Ru(1 1 2̄ 0) surface using low energy electron diffraction, high resolution electron energy loss spectroscopy and thermal desorption spectroscopy at room temperature. Two ordered CO phases were observed, a p(1×2) phase formed at θCO=0.25 and a (1×2)p2mg phase formed at θCO=0.5 (saturation). In both phases, the CO molecules occupy the on-top sites. Two structural models are suggested.