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MA: Fachverband Magnetismus

MA 29: Magnetic Semiconductors I

MA 29.6: Vortrag

Donnerstag, 25. März 2010, 16:30–16:45, H22

Analysis of electric dipolar and quadrupolar transitions in X-ray absorption spectroscopy for Co doped ZnO — •Mehmet Kaya, Andreas Ney, Carolin Antoniak, and Heiko Wende — Fakultät für Physik and CeNIDE, Universität Duisburg-Essen, Duisburg, Germany

Co doped ZnO (Co:ZnO) is a promising candidate for dilute magnetic semiconductor devices. To realize a practical device, it is essential that a magnetic order is present above room temperature. Co:ZnO has been intensively investigated and there exist controversial results regarding its magnetic behavior. The authors in [1] report an absence of intrinsic ferromagnetic interactions of isolated and paired Co dopant atoms in Co:ZnO.
For optimum magnetic properties the analysis of the local structure is vital. The local structure can be studied by the linear dichroism in the X-ray absorption spectroscopy. We present an ab-initio study of XANES spectra of Co:ZnO using self-consistent potentials and full multiple scattering calculations. The calculations were made using the FEFF 8.4 code [2]. The results show a good agreement to experimental data. We present also an analysis of electric dipolar and quadrupolar transitions in the calculated spectra by comparison with the angular momentum resolved density of states. Furthermore our calculations will be compared to simulations obtained with the FDMNES code [3].

1 Ney, A., et al. Phys. Rev. Lett. 100, 157201, (2008).

2 Ankudinov, A. L., et al. Phys. Rev. B. 58, 7565, (1998).

3 Joly, Y. Phys. Rev. B. 63, 125120, (2001).