Zur Struktur der Leitungsbänder der kubisch-raumzentrierten Übergangsmetalle

Abstract

X-ray isochromats of Tantalum, Niobium and Tungsten for different temperatures are presented. They allow a localization of the Fermi edge in the conduction band and show, that the fine structure softens with increasing temperature. This is attributed to a change in the density of states in the conduction band. A modified rigid band model of the density of states for the bcc transition metals is constructed. It agrees well with our isochromats and with published calculations of the density of states for Tungsten. Other electronic properties also fit well into this model. In connection with the interpretation of our isochromats a short discussion of precision experiments for the evaluation ofh/e is added.