Topological Quasi-2D Semimetal Co3Sn2S2: Insights into Electronic Structure from NEXAFS and Resonant Photoelectron Spectroscopy.

The electronic structure of the natural topological semimetal Co3Sn2S2 crystals was studied by using near-edge X-ray absorption spectroscopy (NEXAFS) and resonant photoelectron spectroscopy (ResPES). Although, the significant increase of the Co 3d valence band emission is observed at the Co 2p absorption edge in the ResPES experiments, the spectral weight at these photon energies is dominated by the normal Auger contribution. This observation indicates the delocalized character of photoexcited Co 3d electrons and is supported by the first-principle calculations. Our results on the investigations of the element- and orbital-specific electronic states near the Fermi level of Co3Sn2S2 are of importance for the comprehensive description of the electronic structure of this material, which is significant for its future applications in different areas of science and technology, including catalysis and water splitting.