Size Distribution of Zinc-Cesium and Cadmium-Cesium Positive Cluster Ions Using Secondary Ion Mass Spectrometry

Abstract

Abundance distributions were studied for cadmium-cesium and zinc-cesium positively charged cluster ions. The cluster ions were produced by Cs⁺ ion bombardment on initially pure metal sheets of either cadmium or zinc, and mass analysis was performed using a grand-scale sector mass spectrometer. Mass spectra revealed the abundance distributions indicating that specific clusters having 8, 20, 34, 40, and 58 valence electrons were particularly stable. Observed abundances of [Cd_nCs]⁺, [Zn_nCs]⁺, and [Zn_n-2Cs₂]⁺ can be fully explained in terms of the electronic-shell structures of the metals studied. It was found that the origin of the “magic numbers” are different from those of Hg_nCs⁺ cluster.