Frank de Groot1
Utrecht University1
Transition metal K edges are related to excitations of the transition metal 1s core electron to empty states. The K edges can be divided into the excitonic 3d pre-edges and the main edge that describes the excitations to the empty metal p-states.Using High-Energy-Resolution-Fluorescence-Detection (HERFD), one can sharpen the pre-edge structures revealing their multiplet nature. They can be calculated from the transition from the 3d<sup>N</sup> ground state to the 1s<sup>1</sup>3d<sup>N+1</sup> final state [1]. The main edge is usually interpreted from the calculation of the transitions to empty states, using DFT theory, for example multiple scattering (FEFF). The 1s XPS spectra of transition metal oxides show multiple peaks, implying that one photon energy gives rise to electrons with multiple kinetic energies. This implies that the 1s XAS spectral shape must be described as the convolution of the empty states with the 1s XPS spectral shape [2].<br/> We measured the iron, cobalt and nickel K edges of thin film perovskite-based electrodes at the solid-liquid interface to probe the oxygen evolution reaction (OER). The 3 nm thin perovskite films are measured in fluorescence yield through the backside of the membrane electrodes.<br/>----------------------------------------------------<br/>de Groot et al. J. Phys. Cond. Matt. 21, 104207 (2009)<br/>Ghiasi et al., Phys. Rev. B. 100, 075146 (2019)