Berlin 2012 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 46: MagneticThin Films II

MA 46.7: Vortrag

Donnerstag, 29. März 2012, 16:30–16:45, EB 202

All-Electron Hybrid-Functional Calculations of the Europium Chalcogenides — •Martin Schlipf, Markus Betzinger, Marjana Ležaić, Christoph Friedrich, and Stefan Blügel — Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425 Jülich, Germany

High spin polarization in the Eu chalcogenides offers the prospect of efficient spin filters in semiconductors. EuO is particularly suited as it exhibits the highest Curie temperature among these materials and can be grown epitaxially on Si, GaN, and GaAs. Throughout the EuX (X = O, S, Se, Te) series, as the chalcogenide atoms become bigger, the band gaps increase whereas the magnetic coupling constants decrease, giving rise to a FM to AFM transition. For our theoretical investigation, we employ the hybrid exchange-correlation functionals PBE0 and HSE, which incorporate a fraction of nonlocal Hartree-Fock exchange and thus extend the realm of density functional theory (DFT) to strongly correlated materials. We present the electronic, structural, and magnetic ground state as predicted from first-principle calculations using the FLAPW method FLEUR, in which recently hybrid functionals were implemented [1,2]. The results show an excellent agreement with experimental observations from the literature. We investigate trends across the series and focus in particular on how the material properties are modified when the chalcogenide atom is changed.
We acknowledge funding by HGF-YIG, contract VH-NG-409.
[1] M. Betzinger, et al., Phys. Rev. B 81, 195117 (2010).
M. Schlipf, et al., Phys. Rev. B 84, 125142 (2011).