Regensburg 2010 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 33: Poster II

MA 33.10: Poster

Freitag, 26. März 2010, 11:00–14:00, Poster B1

Influence of exchange and correlation on the magnetic ground state of MnO — •Andreas Schrön, Claudia Rödl, and Friedhelm Bechstedt — Institut für Festkörpertheorie und -optik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany

Transition-metal oxides (TMOs) are of great interest for applications in e.g. dilute magnetic semiconductors (DMSs) which are supposed to allow for transparent ferromagnets with critical temperatures around room temperature. Although TMOs have been investigated a long time experimentally, their theoretical description is still unsatisfying. (Semi-)local approximations like local spin-density approximation (LSDA) or generalized-gradient approximation (GGA) to density functional theory (DFT) work well for many materials, but fail for TMOs, since they do not account sufficiently for the electron correlation effects.

We present an ab-initio study of structural, electronic, and magnetic properties of MnO within the DFT framework. Results obtained within GGA are compared with findings taking into account an additional on-site Coulomb interaction U (GGA+U) and results using the non-local hybrid exchange-correlation functional HSE03. Besides the rock-salt structure, which is the natural ground-state structure of MnO, we focus especially on the properties of MnO in the hypothetical wurtzite structure, the ground-state structure of e.g. ZnO, a potential host material for DMSs. We present our results considering six different magnetic orderings for both crystal structures, respectively, and compare them with experimental and other theoretical data.