Production and mass spectroscopic characterization of multiple metal-rich alkali halide clusters

Abstract

Multiple metal-rich alkali halide clusters and ammonium halide clusters from solid crystals of NaF, CsI and NH 4I have been produced and characterized by a newly developed high-pressure laser-vaporization cluster source. The observed metal-rich clusters, Na n F m + ( n∼40, n− m=1–9) and Cs n I m + ( n∼60, n− m= 0–5), have enhanced species at n=14 being independent of m, which implies the existence of multiple excess electrons. Furthermore, the ammonium halide clusters, NH 4 +(NH 4I) n ( n∼32), have a similar stoichiometry to typical alkali halide clusters. These results indicate that the present high-pressure laser-vaporization cluster source is suitable for producing these unstable clusters with unique stoichiometry.