STRUCTURE AND PROPERTIES OF NI(110) SURFACE COADSORBING CHLORINE AND OXYGEN

The coadsorption of chlorine with oxygen on Ni(110) surface has been i nvestigated by XPS, UPS, AES and work function measurements. The chlor ine preadsorption drastically inhibits the further uptake of oxygen. O n the contrary, precovered oxygen has hardly any influence on the addi tional adsorption of chlorine due to the incorporation of precovered o xygen into the subsurface driven by the chlorine coadsorption. ARXPS m easurements provide the evidence for this coadsorption model. The ther mal desorption of chlorine and oxygen from the coadsorption surface is very similar to that of both individual adsorbates under the same hea ting conditions, but the desorption temperature of both the adsorbates apparently decreases on the coadsorption surface. The coadsorption an d thermodesorption mechanisms are also discussed in detail.