ELECTRONIC-STRUCTURE OF TUNGSTEN AND MOLYBDENUM GERMANIDES SYNTHESIZED AT HIGH-PRESSURES

X-ray emission spectroscopy. (XES), X-ray absorption spectroscopy (XAS ), and X-ray photoelectron spectroscopy (XPS) methods were used to stu dy the electronic structure of WGe2, W5Ge3, and MoGe2 compounds formed in a high temperature-high pressure treatment. Transformations of the electronic structure after termination of the alpha-->beta irreversib le polymorphic transitions in the tungsten and molybdenum digermanides have been investigated. The XES bands and XAS edges in all compounds studied have been derived and compared in a single energy scale. The X PS core-level binding energies have been determined. In the germanides a small amount of charge transfers from the Ge atoms to the M atoms ( M = W, Mo). In the molybdenum and tungsten germanides the M d(p)-like valence states and Ge 4p-like states are strongly hybridized.