VALENCE-BAND PHOTOEMISSION FROM DEPOSITED METAL-CLUSTERS - CASE-STUDIES

Metal clusters (Pb(N), Au(N)) grow in a pulsed arc cluster ion source (PACIS). After supersonic expansion in the helium carrier gas the resu lting beam is soft-landed under UHV conditions on either cold polycris talline silver, Si(111) or natural SiO2. Photoemission measurements wi th light from the synchrotron BESSY serve to investigate the electroni c structure of the clusters. In this communication, valence band photo emission is presented for Pb(N) on Ag, Pb(N) on Si/SiO2 and Au(N) on A g. After lead deposition, the valence band region exhibits only low, w eakly structured intensity, whereas deposited gold clusters lead to th e formation of a resolved narrow peak at 3.52 eV below epsilon(F), whi ch we attribute to Au 5d5/2.