ONE-DIMENSIONAL AND 2-DIMENSIONAL SURFACE-STATES ON METALS

The influence of surface states on the physics and chemistry of metal surfaces is demonstrated by a few examples. An introduction is given to surface state models and general symmetry properties of their wavefunctions with focus on Shockley surface states of fee transition and noble metal surfaces. Their role in the adsorbate induced reconstruction is studied on the system Na/Cu(110). The existence of one-dimensional (1D) surface states in the 1D-disordered system H/Ni(110) is demonstrated and mechanisms for the localization are discussed. Finally, it is shown that surface states influence the charge density outside a surface and thereby determine the strength of the physisorption potential and the barrier height for dissociative adsorption. As a consequence, a new mechanism is proposed for the promotion of catalytic reactions.