Electronic structure of liquid transition metals studied by time resolved photoelectron spectroscopy

The electronic structure of liquid transition metals has been studied by time resolved photoelectron spectroscopy. Distinct changes in the valence band structure across the solid-liquid phase transitions have been observed for Pd, Mo and W. In the case of Pd the changes on melting are caused by a change in the photoemission process itself. For Nb, Mo, Ta and W we suggest a change in the atomic short range order from the bcc structure to an fcc-like short range order in the liquid state which causes a marked change in the valence band spectra of Mo and W due to the ailing up of the pronounced gap in the density of states near the Fermi level. The measurements show that time resolved photoelectron spectroscopy can be used to study high temperature oxidation processes on the microsecond time scale.