Electron energy loss spectroscopy of the L_(2,3) edge of phosphorus skutterudites and electronic structure calculations

摘要

In this study we report the results of experiments and theoretical calculations on the phosphorus L_(2,3) edges of the skutterudites CoP_3, LaFe_4P_(12), NiP_3, RhP_3, and IrP_3. Phosphorus s and d density of states above the Fermi level was studied by transmission electron energy loss spectroscopy while theoretical calculations were performed using both a real-space multiple-scattering procedure and density-functional theory. Generally, there are good agreements between both types of calculations and the experimental results. The near-edge structure of all the examined compounds shows the same overall features, including the metallic NiP_3 and the metallic filled skutterudite LaFeP_(12), and is well explained by comparison to phosphorus density of states. We also discuss the similarities to previously reported results on Si L_(2,3) edges and interpret the differences of the various skutterudites in terms of the electronegativities of the involved atom species.