PES of liquid early transition metals with high vapour pressures

The investigation of the electronic structure of liquid elements with photo electron spectroscopy is restricted to some 20 elements of the periodic tab le. This restriction is mainly due to the high vapour pressures of most ele ments in the liquid state and the need of ultra high vacuum conditions in t he spectrometer. To overcome this limit we introduced the new technique of time-resolved photoemission during pulsed laser heating. This technique all owed us to measure several elements in the liquid state, not accessible by conventional photoemission, of which the early transition metals Ti,V, Zr, Nb, Mo, Hf, Ta and W are presented here. The use of eight subsequent time w indows also enabled us to observe the solid-liquid phase transition reveale d by the changes in the valence band spectra. These neighbouring elements w hich nearly cover a square area of the periodic table were chosen to show a n overall trend in the liquid state when going from 3d to 5d metals and var ying the number of d-electrons. Furthermore a well known solid-solid phase transition (hcp --> bcc) could be observed for the elements Ti and Zr. (C) 2001 Elsevier Science B.V. All rights reserved.