The cobalt and iron clusters CoN, FeN (20 < N < 150) measured in a cryogenic molecular beam are found to be bistable with magnetic moments per atom both {mu}N/N 2{mu}B in the ground states and {mu}N */N {mu}B in the metastable excited states (for iro
n clusters, {mu}N ~3N{mu}B and {mu}N* N{mu}B). This energy gap between the two states vanish for large clusters, which explains the rapid convergence of the magnetic moments to the bulk value and suggests that ground state for the bulk involves a superposition of the two, in line with the fluctuating local orders in the bulk itinerant ferromagnetism.
Water clusters embedding a nitric acid molecule HNO3(H2O)_{n=1-10} are investigated via electrostatic deflection of a molecular beam. We observe large paraelectric susceptibilities that greatly exceed the electronic polarizability, revealing the cont
ribution of permanent dipole moments. The moments derived from the data are also significantly higher than those of pure water clusters. An enhancement in the susceptibility for n=5,6 and a rise in cluster abundances setting in at n=6 suggest that dissociation of the solvated acid molecule into ions takes place in this size range.
