Stern-Gerlach Deflection of Metallic-Cluster Beams

Supersonic argon beams containing clusters of from 1 to 100 potassium atoms show magnetic deflection patterns with three components: atoms, undeflectable clusters comprising mainly even numbers of atoms, and clusters with odd numbers of atoms. The magnetic moments of the light odd clusters are approximately 1${\mathrm{\mu }}_{\mathrm{B}}$.