ISSN:
1089-7690
Quelle:
AIP Digital Archive
Thema:
Physik
,
Chemie und Pharmazie
Notizen:
Using the coverage grating-optical second-harmonic diffraction method, we have measured the diffusion rate of potassium on Re(001) in the coverage range of 0.6–1 ML. We observe a minimum in both the activation energy for diffusion and the diffusion preexponential at an initial potassium coverage of 0.75 ML. For potassium coverages of 0.93, 0.84, 0.73, and 0.59 ML, the activation energies for diffusion are determined to be 5.0±0.2, 3.9±0.7, 3.6±0.2, and 5.0±1.0 kcal/mol, and D0 is 5.6×10−3±0.3, 3.5×10−4±1.1, 5.8×10−4±0.3, and 3.7×10−1±1.9 cm2/s, respectively. The results are discussed in terms of electrostatic dipole–dipole repulsive interactions among neighboring adsorbates. © 1997 American Institute of Physics.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1063/1.474231