PULSED-FIELD IONIZATION ZERO KINETIC-ENERGY PHOTOELECTRON-SPECTROSCOPY OF SMALL VANADIUM CLUSTERS - USING VELOCITY SLIP AS A MASS SELECTOR

The pulsed field ionization zero kinetic energy photoelectron spectros copy technique has been used to determine accurate ionization potentia ls for the small metal clusters V-3 and V-4. Direct single-photon lase r ionization was used. Assignment of the carrier of the photoionizatio n spectra is aided by the velocity slip of the seeded cluster beam whi ch provides a degree of mass separation in the neutral cluster molecul es prior to ionization and, thereby, the ability to cross-correlate th e PFI-ZEKE spectra with particular cluster species.