Dresden 2009 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 11: Magnetic Materials
MA 11.2: Vortrag
Montag, 23. März 2009, 15:30–15:45, HSZ 103
Electronic and magnetic properties of Gd-based materials: Beyond the LDA — •Samir Abdelouahed1, Mebarek Alouani2, and Jürgen Henk1 — 1Max Planck Institute of Microstructure Physics, Halle, Germany — 2Institut de Physique et de Chimie des Matériaux de Strasbourg (IPCMS), France
The FLAPW method has been used to study the electronic structure of gadolinium-based materials. The 4f electron-electron interaction was treated by the LDA+U method to improve the description of electronic and magnetic properties. For gadolinium, x-ray absorption spectroscopy (XAS) and x-ray magnetic circular dichroism (XMCD) spectra calculated including U agree better with experiment, as compared to those of the standard LDA (GGA) treatment. Furthermore, the XMCD spin and orbital moments, obtained from the sum rules, compare favorably to the self-consistent results.
The tiny magnetocrystalline anisotropy energies (MAE's) of bulk Gd, GdN, and GdFe2 have been calculated by means of the magnetic-force theorem. The energy position of the 4f-state affects significantly the MAE's. For example, the magnetic anisotropies in GGA and in GGA-core calculations are factors of about 10 and 3 larger than that of the GGA+U approach, indicating the importance of hybridization in these systems.