ADSORPTION ON OXIDE SURFACES - STRUCTURE AND DYNAMICS

In contrast to metal surfaces, oxide surfaces have only been studied r ather recently with surface science methods. We report on the preparat ion and electron spectroscopic investigations of thin, well ordered su rfaces of clean, adsorbate covered and modified oxide films. We identi fy surface excited states of a NiO(100) surface via electron energy lo ss spectroscopy in the regime of electronic excitations. Adsorption on well ordered terraces and on defects can be distinguished by choosing proper probe molecules. As a model system to study the structure and reactivity of an oxide supported ultrathin metal film we have deposite d Pt onto a thin Al2O3(111) film grown on a NiAl(110) substrate. CO ad sorption and low temperature dissociation in contrast to the bulk Pt h as been observed.