CC BY 4.0 UnportedAragón Sánchez, JazmínAmigó, María LourdesBelussi, Cristian HoracioAle Crivillero, María VictoriaSuárez, SergioGuimpel, JulioNieva, GladysGayone, Julio EstebanFasano, Yanina2023-01-312023-01-312022https://oa.tib.eu/renate/handle/123456789/11165http://dx.doi.org/10.34657/10191The electronic properties of Fe-based superconductors are drastically affected by deformations on their crystal structure introduced by doping and pressure. Here we study single crystals of FeSe 1 − x Sx and reveal that local crystal deformations such as atomic-scale defects impact the spectral shape of the electronic core level states of the material. By means of scanning tunneling microscopy we image S-doping induced defects as well as diluted dumbbell defects associated with Fe vacancies. We have access to the electronic structure of the samples by means of x-ray photoemission spectroscopy (XPS) and show that the spectral shape of the Se core levels can only be adequately described by considering a principal plus a minor component of the electronic states. We find this result for both pure and S-doped samples, irrespective that in the latter case the material presents extra crystal defects associated to doping with S atoms. We argue that the second component in our XPS spectra is associated with the ubiquitous dumbbell defects in FeSe that are known to entail a significant modification of the electronic clouds of surrounding atoms.enghttps://creativecommons.org/licenses/by/4.0530atomic scale defectselectronic core levelsFe-based superconductorsSTMXPSArticle