Temperature‐dependent electronic properties for 4f states in cerium mononitride

Abstract

AbstractIn order to elucidate the temperature‐dependent occupancy number of Ce 4f electrons and valence state of Ce ions in cerium mononitride (CeN), we perform an ab initio calculation by using a many‐body scheme combing density functional theory with dynamical mean field theory, taking into account the spin‐orbit coupling (SOC) interaction and on‐site Coulomb repulsion between Ce 4f electrons. Results demonstrate that Ce 4f j = 5/2 and j = 7/2 manifolds undergo insulating‐metallic transition with increasing of temperature. Ce 4f‐conduction electrons hybridization, f‐f correlation, SOC interaction and final state effects yield a complicated spectrum function in CeN. Ce 4f atomic configuration transition and hybridization might be responsible for the temperature‐dependent occupancy number of Ce 4f electrons and the mixed‐valence state in CeN. A fact that localization of Ce 4f electrons, that is, 4f1 configuration or Ce3+ valence, increases with increasing of temperature could account for the experimentally observed lattice constant versus temperature data. Finally, the so‐called quasiparticle band structure is also discussed for comparison with experimental angle‐resolved photoemission spectrum.