Abstract
We present a quantitative analysis on the electron energy loss spectra (EELS) of potassium (K) doped C-60 thin films collected as a function of time to explore the diffusion of K atoms at and near the surface at 100 K. The spectral features of K3C60, K4C60, K6C60 and pure C-60 phases were observed to coexist before reaching saturation doping. The ratio of these phases can be controlled by the K deposition rate. At low deposition rate, we found no trace of K3C60 at the surface. A quantitative analysis, based on fits using Lorentzian functions characteristic of each structural phase, is used to monitor the time and dose variation of the multiphase-film. The analysis gives the dissipation rates of K4C60 and K6C60 phases at the surface together with the peak broadening of the LUMO-LUMO+1 transitions of K4C60 and K6C60 structures as a function of grain size. The results give insights into the relative kinetic stability of KxC60 grains, as x is varied. (C) 2002 Elsevier Science B.V. All rights reserved.
Original language | English |
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Pages (from-to) | 168-178 |
Number of pages | 11 |
Journal | Surface Science |
Volume | 523 |
DOIs | |
Publication status | Published - 10 Jan 2003 |
Keywords
- fullerenes
- adsorption kinetics
- electron energy loss spectroscopy (EELS)
- alkali metals