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

Multiple metal-rich alkali halide clusters and ammonium halide clusters from solid crystals of NaF, CsI and NH4I have been produced and characterized by a newly developed high-pressure laser-vaporization cluster source. The observed metal-rich clusters, NanFm+ (n∼40, n−m=1–9) and CsnIm+ (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, NH4+(NH4I)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.