Formation mechanisms of high-entroopy spinels studied by coupled X-ray diffraction, total scattering and absorption spectroscopy

Using combined X-ray diffraction (XRD), total scattering (TS), and X-ray absorption spectroscopy (XANES) experiments, we want to study the formation of high entropy oxides (HEO) in a sol-gel synthesis. HEOs are a new type of material containing five or more metal cations in a single-phase crystal structure. We have synthesized a series of HEOs in a spinel structure based on 1st-row transition metals (Cr, Mn, Fe, Co, Ni, Cu), which have immense potential as e.g., catalysts for oxygen evolution reaction (OER). We aim to obtain a mechanistic understanding of the oxide formation pathways in these multi-metallic systems. The combined in situ XRD, TS, and XANES studies will allow us to simultaneously follow changes in the average and local structures as well as oxidation states during the transformation of the amorphous precursors into crystalline products. Such studies have previously shown to give unique insight into the materials formation pathways of novel high entropy materials.