Home

About

Advanced Search

Browse by Discipline

Scientific Societies

E-print Alerts

Add E-prints

E-print Network
FAQHELPSITE MAPCONTACT US


  Advanced Search  

 
Surface Diffusion of Potassium Coadsorbed with CO on Ru(001): A Coverage Grating-Optical Second Harmonic Diffraction Study
 

Summary: Surface Diffusion of Potassium Coadsorbed with CO on Ru(001): A Coverage
Grating-Optical Second Harmonic Diffraction Study
I. M. Danziger, B. Hallac, and M. Asscher*
Department of Physical Chemistry and the Farkas Center for Light Induced Processes, The Hebrew UniVersity,
Jerusalem 91904, Israel
ReceiVed: February 16, 2004; In Final Form: July 6, 2004
The effect of coadsorbed CO on potassium surface diffusion on Ru(001) has been studied using coverage
grating-optical second harmonic diffraction method. The enhancement of the first-order diffraction peak at
0.06 ML of CO coadsorption coverage demonstrates the very strong electronic interaction between these
coadsorbates. At an initial potassium coverage of 1.0 ML, the activation energy for the diffusion of K increases
from 2.7 kcal/mol on the clean ruthenium surface to 17.0 kcal/mol in the presence of 0.06 ML CO. At 280
K, the diffusion rate coefficient drops from D ) 6.4 10-10 cm2/s on clean ruthenium to D ) 1.5 10-14
cm2
/s as a result of CO coadsorption. CO and K stabilize each other upon the formation of Ky-COx surface
complexes that increase the apparent activation energy for potassium diffusion, thereby slowing its diffusion
rate.
1. Introduction
Surface diffusion has become a popular subject for research
with the development of scanning-probe microscopy, such as
STM and AFM. Studies of diffusion have primarily emphasized

  

Source: Asscher, Micha - Institute of Chemistry, Hebrew University of Jerusalem

 

Collections: Chemistry