Many-body Approach for XAS and XMCD Applied to Ferrites
ORAL
Abstract
X-ray absorption spectroscopy is an important tool to extract element-specific information about the electronic structure, magnetism and in particular electronic correlation effects.
Ab initio calculations have a hard time reproducing the 2p to 3d excitation, in particular for strongly correlated materials and significant influences due to the core-hole. In this work, a combination of density functional theory and multiplet ligand field theory is used to bridge this gap. For this, we calculate parameters from first principles and use them to construct a single-impurity Anderson model by projecting the local Hamiltonian and the hybridization function onto the 3d states. We apply this method among other things NiFe2O4, CoFe2O4 and Fe3O4 and find systematically good agreement with the experiment for both XAS and XMCD spectra.
Ab initio calculations have a hard time reproducing the 2p to 3d excitation, in particular for strongly correlated materials and significant influences due to the core-hole. In this work, a combination of density functional theory and multiplet ligand field theory is used to bridge this gap. For this, we calculate parameters from first principles and use them to construct a single-impurity Anderson model by projecting the local Hamiltonian and the hybridization function onto the 3d states. We apply this method among other things NiFe2O4, CoFe2O4 and Fe3O4 and find systematically good agreement with the experiment for both XAS and XMCD spectra.
*Financial support from Vetenskapsrådet, and the Knut and Alice Wallenberg foundation is acknowledged.Computations were enabled by resources provided by the Swedish National Infrastructure for Computing (SNIC) at NSC, partially funded by the Swedish Research Council.
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Presenters
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Felix Sorgenfrei
- Uppsala University, Sweden
- Uppsala University