ELECTRONIC-STRUCTURE OF NBXMO100-X SOLID-SOLUTIONS

NbxMo100-x solid solutions (0 less than or equal to x less than or equ al to 100) have been studied by means of photoelectron spectroscopy in order to obtain direct information concerning the electronic density of states of the alloy. Detailed knowledge of the density of states is relevant to the discussion of electronic properties such as the super conducting transition temperature. Changes observed in the valence-ban d spectra as a function of systematic changes in x follow a very simpl e law proposed in the early days of solid-state physics known as the r igid-band model (RBM). The observed binding energy shifts of the ''rig id'' valence band on alloying agree fairly well with predictions based on modern band-structure calculations for the pure components, verify ing that this simple model can be used even quantitatively as has been assumed in the past. The dependence of the superconducting transition temperature on the concentration can be very well understood on the b asis of this RBM description of the electronic structure.