A new approach of the SIMS method for metal clusters

The size distributions of (CsICs+, (MgO)(n)(+) (MgOMg+, and (Hg)(n)M(j)(+) (M: alkali metal, j = 1, 2, 3, 4, 5) clusters were obtained using secondary-ion mass spectrometry. The sizes of stable neutral clusters (CsI)(n) and (Hg)(n) clusters were determined from the mass spectra of cluster ions (CsICs+ and (Hg)(n)M(+). The magic numbers of (Hg)(n)K-3(+) clusters were identical to those of van der Waals type clusters. It is believed that the shell closing cluster K-3(+) is at the center of complex clusters (Hg)(n)K-3(+). The (Hg)(n)K-4(+) clusters were believed to have electronic shell structures from the magic numbers.