Electronic structure of perovskite-type YBRh₃: X-ray photoelectron spectroscopy and ab initio band calculations

The perovskite structure type YBRh₃ was synthesized by the arc melting method. Its electronic structure was studied by XPS and ab initio band calculations. The chemical shifts of the Y and Rh 3d levels from the elements were negative. The experimental and calculated valence band XPS coincided well with each other. The band calculation indicated that the metallic behavior of the compound originates from the Rh 4d electrons. The atomic distance between Y and Rh is 93% of the sum of the radii of the elements. The electron density has a maximum between the Y and Rh atoms, and the distance between the maximum point and center of the Y atom is 77% of its atomic radius. This indicates that charge transfer occurs from Y to Rh. The nearly equal electronegativities of B and Rh result in a covalent bond between them, which is shown as an asymmetric electron distribution in the circumference of the B and Rh atoms. The covalent bond results from hybridization of the B 2p and Rh 4d levels.