The evolution of electronic structure in lanthanide metal clusters: Threshold photoionization spectra of $\sf Ce_{ n}$ and $ \sf Pr_{ n}$

Abstract

The photoionization spectra of Pr2-Pr21 and Ce2-Ce17 have been measured near threshold. The ionization potentials (IPs) of \(\) and \(\) vary discontinuously with size, but trend downward toward the work function of the bulk metals. In general, the IPs of cerium clusters display more variation than those of praseodymium clusters. The sudden discontinuities observed in the IPs of both \(\) and \(\) is akin to that displayed by clusters of transition metal atoms, suggesting that as in transition metal clusters, the rapid evolution in geometric structure with size is the source of these discontinuities.