Regensburg 2004 – wissenschaftliches Programm
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MA: Magnetismus
MA 13: Poster:Schichten(1-23),Spinabh.Trsp(24-41),Exch.Bias(42-56),Spindyn.(57-67),Mikromag.(68-76),Partikel(77-90),Spinelektr.(91-97),Elektr.Theo.(98-99),Mikromag+PhasÜ+Aniso.(100-105),Magn.Mat.(106-118),Messmethod.(119-121),Obflm.+Abbverf.(122-123)
MA 13.96: Poster
Dienstag, 9. März 2004, 15:00–19:00, Bereich A
Magnetic properties of Mn, Cr or V implanted GaN. — •V.A. Guzenko1, N. Thillosen1, A. Dahmen1, N. Kaluza1, Th. Schäpers1, M. Luysberg2, and L. Houben2 — 1Institute of Thin Films and Interfaces (ISG1) and CNI - Center of Nanoelectronic Systems for Information Technology , Research Centre Jülich, 52425 Jülich, Germany — 2Institute of Solid State Research and CNI - Center of Nanoelectronic Systems for Information Technology , Research Centre Jülich, 52425 Jülich, Germany
The possible application of dilute magnetic semiconductors (DMS) in spintronics devices impelled intensive search for materials with Curie temperatures above 300K. On the basis of theoretical predictions a promising candidate is GaN, doped by Mn up to 5 at.%. Recently, many groups reported on the successful fabrication of ferromagnetic GaN:Mn layers grown by molecular beam epitaxy. We followed a different approach by implanting 3d-transition metals into GaN.
GaN layers grown by MOVPE on sapphire substrates were implanted with Mn, Cr or V ions with a dose of 5×1016 cm−2. The implantation energy was 200 keV. Subsequently, rapid thermal annealing in N2 atmosphere for 5 min at 700∘C was performed. The magnetization of our samples, investigated by SQUID-magnetometer, as a function of magnetic field as well as temperature revealed paramagnetic behaviour for all samples. Depending on measurement conditions a hysteresis in magnetization could be observed. These results can be explained by the presence of clusters of a 3d-metal rich secondary phase, which is confirmed by TEM and channelling measurements.