From x-ray-absorption near-edge structures to the<i>d</i>-hole population in Pd-Ag alloys

Abstract

The charge transfer upon alloying and the screening of the core hole in the x-ray absorption process in Pd-Ag alloys are discussed according to different models and with respect to different quantities. The charge transfers are analyzed using the first-principles electronic structure and spectrum calculations based on the linear muffin-tin orbitals method. Experimentally, both Pd and Ag gain d charge and lose non-d charge in Pd-Ag compared to pure Pd and Ag. The theoretical result agrees with the experimental one for Pd whereas the calculated charge transfer for Ag is in contradiction with the experimental result. This discrepancy is attributed to the differences in the electronic structure of Pd and Ag requiring new interpretation of the Ag x-ray-absorption near-edge structures of Pd-Ag alloys.