Surface-Induced Dissociation as a Probe for the Energetics and Structure of Lead Clusters

Abstract

Fragmentation of lead cluster ions (Pb N +: N = 2–20) in low-energy collisions with a highly oriented pyrolytic graphite surface has been investigated by means of a tandem time-of-flight mass spectrometer. At low incident energies, all clusters fragment dominantly by an atom loss process. This behavior is characteristic for clusters of metallic elements, but in contrast to Si N +, Ge N + and Sn N + clusters. The results therefore demonstrate differences in the electronic and geometric structure between lead clusters and the lighter group-14 element clusters. The low energy dissociation patterns were compared successfully with a recent theoretical study on lead cluster fragmentation, supporting the idea, that lead clusters cations already show signatures of metallic behavior unlike Si N +, Ge N + and Sn N + clusters of the same size.