THERMODYNAMICAL PROPERTIES OF IONIZED LITHIUM-OXIDE CLUSTERS, LI2N+PON+

Lithium oxide clusters Li2n+pOn+ are generated by combining reactive n ucleation in a gas aggregation source and photoionization. Unimolecula r dissociation of mass selected cluster ions provides evidence that th e excess of metal atoms evaporates first leading to the most stable sp ecies Li+(Li2O)n, which then evaporate Li2O Molecules. The evaporation rate behavior as a function of cluster size demonstrates that Li+(Li2 O)n can be prepared with different temperatures. It is discussed how m etal evaporation from metal-rich oxide clusters leads to oxygen satura ted clusters with a lower temperature. An estimate of the dissociation energies of Li+(Li2O)n are given for small sizes n less-than-or-equal -to 10 from photoevaporation experiment.