INITIAL-STAGES IN THE FORMATION OF A CSAU SURFACE ALLOY

Threshold photoemission spectroscopy is used to study the formation of a CsAu alloy during deposition of Cs on an Au substrate. It is shown that both the Cs surface layer and the CsAu near-surface alloy undergo indirect photoexcitation. It is found that the formation of a CsAu al loy is accompanied by a sharp rise (by several factors of ten) in the photoemission current while the photoemission threshold remains almost constant. This behavior is attributed to the formation of a band of e lectronic states near the Fermi level. (C) 1998 American Institute of Physics. [S1063-7850(98) 02605-6].