Dresden 2006 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
MA: Magnetismus
MA 25: Spin-Electronics I
MA 25.5: Vortrag
Donnerstag, 30. März 2006, 11:15–11:30, HSZ 103
Ferromagnetic Gd-implanted ZnO single crystals — •Shengqiang Zhou1, K. Potzger1, F. Eichhorn1, F. Herrmann1, D. Grambole1, M. Helm1, W. Skorupa1, J. Fassbender1, T. Herrmannsdörfer2, and A. Bianchi2 — 1Institute of Ion Beam Physics and Materials Research, Forschungszentrum Rossendorf, P.O. Box 510119, 01314 Dresden, Germany — 2Dresden High Magnetic Field Laboratory, Forschungszentrum Rossendorf, P.O. Box 510119, 01314 Dresden, Germany
In order to introduce ferromagnetic properties, ZnO single crystals have been implanted with Gd ions at 180 keV ion energy and two different fluences. Magnetization reversal hysteresis loops have been recorded using a superconducting quantum interference device. The virgin ZnO shows a pure diamagnetic behaviour. Besides the diamagnetic background, weak ferromagnetism has been observed for the as-implanted films. Post-implantation annealing greatly improved the magnetism. For a fluence of 5x10^15 Gd/cm2, post implantation annealing at 820K in vacuum leads to an increase of the saturation moment up to 1.8 Bohr magneton per Gd at exactly 300 K thus excluding Gd, ZnGd or Gd2O3 secondary phases to be formed. The increase of the saturation moment can be explained along with changes in resistivity due to the annealing reported elsewhere. Moreover magnetic domains were observed up to 2 microns by atomic/magnetic force microscope, which again evidenced the formation of diluted magnetic semiconductor. [1]K. Potzger et al, submitted to J. Appl. Phys. (2005). [2]S. O. Kucheyev et al. J. Appl. Phys. 93, 2972 (2003).