Time resolved valence band photoelectron spectroscopy of liquid palladium and molybdenum

Photoelectron spectroscopy measurements on liquid transition metals are not feasible by conventional steady state experiments because of the elevated vapor pressures of these metals at the melting point. However, dynamic expe riments with surface melting induced by pulsed laser irradiation combined w ith time resolved photoelectron spectroscopy make these experiments possibl e for the first time. Valence band spectra of Pd and Mo have been obtained by this method in both the high temperature solid phase and the liquid phas e under identical experimental conditions. Both the elements reveal distinc t changes in the valence band spectra on melting. The shapes of the 4d band s of the two metals in the liquid phase are in good agreement with the calc ulated spectra based on the ab initio density of states (DOS) calculations. (C) 2000 Elsevier Science B.V. All rights reserved.