Marli Dos Reis Cantarino (European Synchrotron Radiation Facility, Grenoble)
Title: Spin Excitations and Disorder in Cr-doped BaFe₂As₂ Probed by RIXS
Institut Néel, Room E424 (Salle Louis Weil)
Abstract: BaFe₂As₂ is a prototypical Hund’s metal, where Hund’s coupling enhances electronic correlations and stabilizes local moments. Hole doping toward half-filling is expected to further increase correlations, but in the case of Mn and Cr substitution, the impurities also directly perturb the Fe magnetic lattice. Using high-resolution Resonant Inelastic X-ray Scattering (RIXS) and Angle-Resolved Photoemission Spectroscopy (ARPES), we investigate the effects of Cr substitution on spin excitations and electronic structure. We show that Fe-derived magnons are strongly damped by disorder from Cr impurities, becoming overdamped at higher doping, while ARPES reveals contrasting behavior between Cr and Mn substitutions. A localized spin model including disorder reproduces the observed damping, highlighting the dominant role of spatial inhomogeneity. In the second part of the talk, the RIXS capabilities at the ID32 ESRF beamline will be presented, emphasizing the instrumental developments and their potential for addressing broader questions in quantum materials.
