Exploiting energy-dependent photoemission in Si d-metal interfaces: the Si(111)-Pd case

The authors present a synchrotron radiation photoemission results from Si(111) with increasing Pd coverages theta (in monolayer units from 0. 5 to 23 monolayers). The authors have measured photoemission spectra in the Cooper minimum for the Pd 4d electrons (hv equals 130 ev) and outside this region (hv equals 80 ev) where the d emission is strong. By comparing the two cases, one obtains information on the Si(sp) and Pd(d) states. Making use of this, a discussion is presented regarding the coverage dependence of the spectra in connection with the nature of the chemical bond between Si and Pd and the structure of the Si-silicide interface.