Comparative photoemission study of amorphous and crystalline As

Abstract
Careful photoemission (ultraviolet, UPS and x-ray, XPS) studies were performed for amorphous and crystalline As in order to terminate the long-standing controversy upon the feature of the 4p-derived portion of the density of valence states of rhombohedral As. The 4p band of rhombohedral As exhibits a twin-peak structure as in the case of amorphous As. The present results are in line with Shevchik's data rather than those of Ley et al., in which only one broad band is observed in the 4p-derived portion in the spectrum of rhombohedral As.