Electron energy loss spectroscopy of the L2,3 edge of phosphorus skutterudites and electronic structure calculations

In this study we report the results of experiments and theoretical calculations on the phosphorus L-2,L-3 edges of the skutterudites CoP3, LaFe4P12, NiP3, RhP3, and IrP3. 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 NiP3 and the metallic filled skutterudite LaFeP12, and is well explained by comparison to phosphorus density of states. We also discuss the similarities to previously reported results on Si L-2,L-3 edges and interpret the differences of the various skutterudites in terms of the electronegativities of the involved atom species.