NA6PB - A BIMETALLIC CLUSTER OF STRIKING STABILITY

During the course of mass spectral studies on the stability of bimetal lic systems, an exceptionally abundant and stable Na6Pb cluster was di scovered. For given experimental conditions, an intense molecular beam consisting exclusively of the particle Na6Pb is generated via self-as sembly from a mixed vapor of sodium and lead. While this observation i s reminiscent of the discovery of C-60 or Tl8C12, Na6Pb represents the first example of a binary finite-size 'alloy' (approximate to 0.5 nm diameter) exhibiting such extraordinary stability.