Tailoring the interaction strength between gold particles and silica thin films via work function control.

The possibility to modify the adsorption properties of a porous silica/Mo(112) film by controlling its work function has been studied by a combined STM and density-functional theory approach. While the original film is inert towards metal adsorption, Au atoms and clusters can be stabilized on the surface after Li doping. The Li atoms penetrate the topmost silica layer and bind as Li+ cations at the metal-oxide interface, thereby reducing the oxide work function. This induces a charge transfer into Au adatoms, which in turn enables strong Au-silica interaction mediated by a polaronic distortion of the oxide lattice.