Dresden 2006 – wissenschaftliches Programm
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MA: Magnetismus
MA 20: Poster: Films(1-36) Transp(37-56) Ex.Bias(57-67) Spindyn(68-80) Micromag(81-95) Particle(96-109) Imag.+Surface(110-113) Spinelectr(114-122) Theory+Micromag(123-131) Spinstr+Aniso(132-142) MagMat(143-156) Meas(157,158) MolMag+Kondo(159-162) Postdead(163-)
MA 20.16: Poster
Dienstag, 28. März 2006, 15:15–19:15, P1
Electronic Properties of Room-Temperature Ferromagnetic Zn1−xCoxO — •Erwin Biegger1, Mikhail Fonin1, Yuriy S. Dedkov2, and Ulrich Rüdiger1 — 1Fachbereich Physik, Universität Konstanz, 78457 Konstanz, Germany — 2Institut für Festkörperphysik, Technische Universität Dresden, 01062 Dresden, Germany
Diluted magnetic semiconductors (DMS) have become recently the subject of intensive research due to the possibility to utilize both charge and spin degrees of freedom in the same material. The main research in this field is focused on the preparation of ferromagnetic DMS materials with high Curie temperatures which is crucial for possible spintronic applications. Recent theoretical calculations by Dietl et al.1 predicted high temperature ferromagnetism (FM) in some 3d transition metal doped semiconductors, among them Co-doped ZnO. However, up to date experimental reports on the magnetic properties of Zn1−xCoxO are very scattering2 and the origin of FM is far from being understood.
In the present study Zn1−xCoxO films have been prepared by means of magnetron sputtering. Magnetic properties of the Zn1−xCoxO films were investigated by SQUID magnetometery indicating FM behavior above room temperature. X-ray absorption spectroscopy measurements show that Co atoms in Zn1−xCoxO are present in the divalent Co2+ state under a tetrahedral symmetry confirming the proper substitution into the ZnO lattice. The Co 2p-3d resonant photoemission spectroscopy data shows that Co 3d states are present near the top of the valence band.
1 T. Dietl et al., Science 287, 1019 (2000).
2 J. M. D. Coey et al., Nature Mat. 4, 173 (2005).