PARTIAL DENSITIES OF STATES IN AMORPHOUS PD0.81SI0.19

Photoemission and Auger spectra involving both core and valence electrons have been measured for Pd, Si, and a-Pd0.81Si0.19. Partial Pd 4d, Si 3p, and Si 3s densities of states (PDOS) have been derived from these measurements. The Pd 4d PDOS shows a filling of the 4d shell in the amorphous alloy which is accompanied by characteristic changes in the spectral shape of the 4d bands when compared to Pd. The Si PDOS can be divided into 3p derived states that overlap the Pd 4d PDOS and a corelike 3s portion that is located 7 eV below the center of the Pd 4d PDOS. The Si 3p PDOS is bifurcated as a result of Pd 4d-Si 3p hybridization with a local maximum at EF. The Si PDOS is well described by an extension of the virtual-bound-state model of Friedel and Anderson owing to Terakura. Core-level shifts of the order of 0.35 eV reflect changes in relaxation rather than a charge transfer from Si to Pd. © 1979 The American Physical Society.