Dresden 2011 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
DS: Fachverband Dünne Schichten
DS 42: Poster I: Progress in Micro- and Nanopatterning: Techniques and Applications (jointly with O); Spins in Organic Materials; Ion Interactions with Nano Scale Materials; Organic Electronics and Photovoltaics; Plasmonics and Nanophotonics (jointly with HL and O); High-k and Low-k Dielectrics (jointly with DF); Organic Thin Films; Nanoengineered Thin Films; Layer Deposition Processes; Layer Properties: Electrical, Optical, and Mechanical Properties; Thin Film Characterisation: Structure Analysis and Composition; Application of Thin Films
DS 42.85: Poster
Mittwoch, 16. März 2011, 15:00–17:30, P1
Characterization of lattice defects by X-ray absorption spectroscopy in ferromagnetic pure ZnO films — •Jörg Haug1, Angelika Chassé1, Stephan Borek1, Manfred Dubiel1, Muhammad Khalid2, and Pablo Esquinazi2 — 1Department of Physics, University of Halle-Wittenberg, Von-Danckelmann-Platz 3, D-06120 Halle — 2Division of Superconductivity and Magnetism, University of Leipzig, D-04103 Leipzig
ZnO films were grown on graphite substrates by pulsed laser deposition under different nitrogen pressure (0.01 - 1.0 mbar) using a KrF excimer laser. The film thickness was between 60 and 500 nm. X-ray diffraction experiments of (100) and (112) reflections demonstrate the a-plane orientation of pure ZnO films. The line broadening of reflection peaks yield crystallite sizes of approximately 50 nm. The comparison of XRD lattice parameters and Zn-O and Zn-Zn distances as determined by EXAFS experiments at the Zn K edge indicates a mismatch to the structure of ZnO single crystals as well as a slight dependence on nitrogen pressure. X-ray absorption experiments of the near edge region (XANES) show an orientation dependence of signals on x-ray polarization and a correlation between the intensity of 1s to 4p transition with the defect concentration. XANES simulations of Zn K edge by means of a multiple-scattering approach demonstrate the sensitivity to vacancy defects. With that structural models of defect centers has been developed to interpret the experimental data.