Transformation of bonds and redistribution of partial states of valence electrons at α(С23)-WGe 2 →β(С11 b )-WGe 2 high-pressure polymorphic transformation

Abstract

The electronic properties and phase transition of β(C11b)-WGe2 and α(C23)-WGe2 phases were investigated via x-ray emission spectroscopy method and first-principles calculations. The analysis of the comparison of the partial energy distributions of the valence electrons of the β(C11b)-WGe2 and α(C23)-WGe2 phases was also studied. The transformation of interatomic bonds during the polymorphic transition α(C23)-WGe2→β(C11b)-WGe2 under comprehensive compression was proposed. The first-principles calculations showed that the phase transition from the α(C23)-WGe2 phase to the β(C11b)-WGe2 phase occurs under high pressure. Furthermore, the electronic structure calculations indicate that the considered phases are metallic in nature. The results have revealed that the fine-structure peculiarities of the WLβ 5- and GeKβ 2-emission bands match well with the main peaks of the partial densities of the W d- and Ge p- electronic states for the both phases.