ULTRATHIN METAL-FILM GROWTH ON TIO2(110) - AN OVERVIEW

The interface between an oxide substrate and a metal overlayer may cru cially influence the macroscopic behavior of technological devices suc h as sensors, catalysts, ceramics, and semiconductor chips. Hence inve stigations of adsorption, nucleation and growth of ultrathin metal fil ms on metal oxide surfaces have attracted increasing interest during r ecent years. Experimental results on the growth of metal overlayers on a model oxide, TiO2(110), are reviewed. The emphasis is on the very i nitial stages of overlayer growth and on extracting general trends on metal/metal-oxide interaction by comparing results from different meta l overlayers. The electronic and geometric structure, growth mode, int erface formation, and thermal stability of metal films are discussed. The strength of the oxidation/reduction reaction at the interface, the wetting ability and the tendency to form a disordered layer are all r elated to the reactivity of the overlayer metal towards oxygen. We pro pose that 'reactive adsorption' accounts for the observed trends.