Eur. Phys. J. D 11, 403-411 (2000)
https://doi.org/10.1007/s100530070069

The influence of O and C doping on the ionization potentials of Li-clusters

Laboratorium voor Vaste-Stoffysica en Magnetisme, K. U. Leuven, Celestijnenlaan 200D, 3001 Leuven, Belgium

Received: 9 September 1999
Revised: 7 February 2000
Published online: 15 September 2000

Abstract

The influence of doping of Li-clusters by electronegative O and C atoms on the ionization potentials was investigated. Experimentally, we report ionization potentials for bare Li_n clusters (10 ≤ n ≤ 70) deduced from photoionization efficiency spectra. The values are compared with the results for Li_nO and Li_nC clusters. Observed differences are largely attributed to a quantum size effect caused by the segregated molecular part around the impurity, which changes the electron work function. Theoretically, the Fermi and exchange-correlation energies which enter the work function, are calculated in the frame of the augmented plane wave (APW) method by taking explicitly into account the presence of the molecular core. The other contribution to the work function, the moment of the double layer at the cluster surface, is computed by solving the corresponding Poisson's equation.