Response of metal clusters to elastic electron impact

Abstract

We perform a theoretical study of the response of neutral and ionized metal clusters to the elastic impact of slow electrons. We center our attention on Na40 and Na4q+ closed-shell clusters. A phaseshift analysis is performed for both systems. The total cross section for the neutral cluster presents resonances related with the existence of quasibound states when studied as a function of incident energy. For the ionized cluster we show the calculated ratio of the angular distribution to the Rutherford differential cross section, near and far from a resonance. The existence of resonances as well as the associated energies are very sensitive to the mean interaction potential. As a consequence, elastic scattering of slow electrons on clusters could be a useful tool in the study of the electronic structure of clusters. PACS number(s): 36.40.c, 34.80.i

Resonance and Threshold Phenomena in Low-Energy Electron Collisions with Molecules and Clusters

“…Although not dealt with in this review, we mention metal clusters as another object for future studies. One-electron shape resonances in elastic scattering (Bernath et al, 1995;Ipatov et al, 1998a) and collective plasmon resonances in elastic and inelastic electron collisions with metal clusters (Gerchikov et al, 1998;Ipatov et al, 1998b;Connerade et al, 2000) have been predicted in theoretical calculations and wait for experimental confirmation. Measurements of electron capture by sodium clusters (Kasperovich et al, 2000a, b) indicate the validity of the Langevin formula for capture, as modified by employing the full image-charge interaction potential which accounts for the finite size of the cluster (Kasperovich et al, 2000b).…”

Resonance and Threshold Phenomena in Low-Energy Electron Collisions with Molecules and Clusters

“…One-electron shape resonances in elastic scattering (Bernath et al, 1995;Ipatov et al, 1998a) and collective plasmon resonances in elastic and inelastic electron collisions with metal clusters (Gerchikov et al, 1998;Ipatov et al, 1998b;Connerade et al, 2000) have been predicted in theoretical calculations and wait for experimental confirmation. Measurements of electron capture by sodium clusters (Kasperovich et al, 2000a, b) indicate the validity of the Langevin formula for capture, as modified by employing the full image-charge interaction potential which accounts for the finite size of the cluster (Kasperovich et al, 2000b).…”

Image states in metal clusters

“…While the effect of the cluster polarization potential on the scattering [11] and capture [12] cross section has been studied with a variety of different approaches, we will focus in this paper specifically on the bound states that arise from the interaction of the excess electron with its image charges. We report first-principles calculations for jellium clusters with sodium densities as a prototype system for isolated nanoclusters.…”