UCd: A Strongly localized material

Sunermann, M.*; Fujimori, Shinichi   ; Severing, A.*; 12 of others*

UCd is an antiferromagnetic uranium intermetallic compound () with enhanced electron mass and uranium-uranium spacings nearly twice the Hill limit, suggesting a weakly hybridized electronic character. Various X-ray spectroscopy techniques indicate that uranium in UCd adopts the formal U configuration, while core-level photoemission spectroscopy (PES) data of UCd reveal only a weak satellite feature, typically interpreted as a signature of itinerancy. In this work, we present density functional theory (DFT) combined with dynamical mean-field theory (DMFT) calculations of UCd, using material-specific parameters tuned to reproduce valence-band PES spectra at different photon energies, thereby exploiting the energy dependence of photoionization cross-sections. Our results demonstrate that UCd is a highly localized uranium system. Furthermore, core-level spectra obtained from a DFT+DMFT Anderson impurity model reveal that, contrary to common assumptions, the presence or absence of satellite structures is not a reliable indicator of strong correlations or itinerant behavior.