Abstract
The chemisorption of N2O on thin Cs films has been studied by monitoring the time evolution of the sticking probability as well as the kinetics of the low-energy electron emission. By combining the data sets, two time domains become distinguishable: the initial chemisorption stage is characterized by a high sticking probability (0.1,S,1) and by a rather weak low-energy electron emission. The opposite is the case within the late stage where the chemisorption saturates, a very intense electron emission is accompanied by the negligibly low sticking probability of less than 0.01. Such evident anticoincidence between the exoemission and the chemisorption excludes the model of surface harpooning as the elementary process responsible for the electron emission in the late chemisorption stage. A long-term emission decay has also been observed after turning off the flux of chemisorbing molecules. A model is proposed that attributes both, the late chemisorptive and the nonchemisorptive electron emission to the relaxation of a narrow state originated from an oxygen vacancy in the Cs oxide layer terminating the surface. The presence of such a state has been confirmed by the metastable de-excitation spectroscopy @MDS, He*(2S)# .
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
