Dresden 2003 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

MA: Magnetismus

MA 14: Poster: Schichten(1-31), Spinabh.Trsp.(32-47), Exch.Bias(48-54), Spindyn.(55-64), Mikromag.(65-76), Partikel(77-88), Oflmag.(89-92), Spinelektr.(93-98), Elektr.Theo.(99-103), Mikromag+PhasÜ+Aniso.(104-122), MagnMat.(123-134), Messm+Mol-Mag.(135-139), Kondo(140-151)

MA 14.124: Poster

Dienstag, 25. März 2003, 15:15–19:15, Zelt

Electronic and magnetic properties of Sr₂FeMoO₆ — •K. Kuepper¹, H. Hesse¹, M. Neumann¹, B. Gather², and A. Winiarski³ — ¹Universität Osnabrück, Fachbereich Physik, Barbarastr. 7, D-49069 Osnabrück, Germany — ²Universität Osnabrück, Institit für Chemie, Barbarastr. 7, D-49069 Osnabrück, Germany — ³Inst. f. Physik, Schlesische Universität Kattowitz, Polen

Recently colossal magnetoresistance at room temperature has been observed in ordered double perovskites, i. e., Sr₂FeMoO₆ [1]. Although these compounds have been wideley investigated due to their electronic and magnetic properties, the valence state of iron and also the magnetic ordering are still under controversial discussion [2]. We have produced polycrystaline Sr₂FeMoO₆ samples. With help of X-ray Diffraction (XRD) we show that Fe and Mo built up a highly ordered structure of alternating B’O₆ and B”O₆ octahedra within the crystal structure. The electronic structure has been investigated with X-ray Photoelectron Spectroscopy (XPS). We find that the compounds contain iron in a mixed valence state. The Mo 3d spectra do not indicate a Mo-site exchange or crystal field spiltting. We discuss our results for both, XRD and XPS, in the light of theoretical calculations.

References: [1] K.-I. Kobayashi et al., Nature 395 677 (1998), [2] T. Saitoh et al., Phys. Rev. B 66, 035112 (2002)