Abstract
Reports results concerning the binding energies of W(100) 4f surface core levels for clean and hydrogen induced reconstructed surfaces. The authors find that at the temperature of the experiments ( approximately 350K), the clean surface is unreconstructed and gives rise to two surface peaks, on the lower binding energy side of the bulk peak. The first one corresponds to surface atoms and the other to the first underlayer ones. In the case of a reconstructed surface, these two peaks appear at higher binding energies (relative to the previous ones). In the intermediate case, all these peaks coexist, which seems to indicate a reconstruction by domains. The energy positions of these peaks are reproduced well by a theoretical model.