DIET in the Second Layer: An ESDIAD (Electron Stimulated Desorption Ion Angular Distribution) Study of NH3 on a CO Layer on Ni(111) and Ni(110)

摘要

We have recently reported on the interactions of CO and NH3 on nickel surfaces, as determined by the electron stimulated desorption ion angular distribution (ESDIAD) method. In this paper we review that work and present the results of calculations that show the role of the CO layer in DIET phenomena. Tochihara et al. have also studied this system using MQS spectroscopy, and their results are of importance in our conclusions. Our interest here concerns ESDIAD from ammonia absorbed on top of the saturated layer of CO on both the (111) or (110) surfaces of nickel. The work of Tochihara et al. was the first to demonstrate that ammonia adsorbs on the surface of a CO monolayer. This observation was also confirmed by this laboratory where it was found that strong H signals arose from the ESD of adsorbed NH3 above the CO monolayer. Reprints. (jes)