Multiconfigurational approach to XAS and XMCD
Seminário do Grupo Teórico de Materiais - DFMT
Felix Sorgenfrei (PhD Student) - Universidade de Uppsala, Suécia
30/05, 2ª feira, 14h. Ed. Alessandro Volta (Bloco C), sala de seminários José Roberto Leite (nº 110)
L-edge X-ray absorption spectroscopy (XAS) is an important tool to extract element-specific information about the electronic structure, magnetism and in particular electronic correlation effects. Ab initio calculations typically struggle to reproduce the 2p to 3d excitation, in particular for materials with strong electron correlations and significant core-hole effects. The combination of density functional theory and multiplet ligand field theory is applied to fill this gap. Here, parameters are calculated from first principles and used to construct a single-impurity Anderson model by projecting the local Hamiltonian and hybridization function onto the 3d states. In this talk, this method is applied to NiFe2O4, CoFe2O4 and Fe3O4. We find systematically good agreement with experiment for both XAS and XMCD spectra.
