Structure and dynamics of CO overlayers on a hydroxylated metal oxide: the polar ZnO(0001) surface

The adsorption and desorption of CO on the hydroxylated, O-terminated polar ZnO(0001) surface has been studied using He-atom scattering. The experimental results reveal the formation of a physisorbed ordered CO overlayer. In addition to recording angular distributions of elastically scattered He atoms, also the dynamical properties of the CO overlayer have been investigated using inelastic He-atom scattering. With the aid of electronic structure calculations a loss peak with an energy transfer of 7.2 meV is assigned to the frustrated translation of the CO molecule normal to the surface.