A Study of Lithium Clusters by Means of a Quadrupole Mass Analyzer

Lithium clusters were prepared by evaporating lithium in argon at a pressure of 10 -4 ∼10 -2 Torr and the mass numbers of these clusters containing up to 15 atoms and their relative abundances were measured by a quadrupole mass analyzer. In good vacuum lithium was detected as single, electrically neutral atoms. When argon was present, clusters composed of an even number of atoms were always detected. Li 3 and Li 5 were never detected and in the range Li 7 to Li 15 , clusters composed of an odd number of atoms were detected in smaller amounts than was the case for neighbouring clusters containing an even number of atoms.