Regensburg 2007 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 15: Poster:ThinFilms(1-33),Transp.(34-49),ExchBias(50-56),
Spindynamics(57-70),Micro-nanostr.Mat.(71-82),
Particles/Clust.(83-88), Mag.Imag./Surface(89-96),
Spinelectronics(97-109), Theory/Micromag.(110-116),
Spinstruct/Phasetr.(117-128),Magn.Mat.(129-139),
Aniso.+Measuring(140-145), MolMag.(146-152),
MSMA(153-156)
MA 15.105: Poster
Dienstag, 27. März 2007, 15:00–19:00, Poster A
Bulk sensitive HX-PES study of chemically etched Ga1−xMnxAs — •Andreas Müller1, Benjamin Schmid1, Michael Sing1, Jan Wenisch2, Karl Brunner2, Laurens Molenkamp2, Wolfgang Drube3, and Ralph Claessen1 — 1Experimentelle Physik IV, Universität Würzburg — 2Experimentelle Physik III, Universität Würzburg — 3HASYLAB DESY, Hamburg
Diluted magnetic semiconductors (DMS) have gained particular interest in the last years due to their potential in spintronic applications. One promising candidate for future devices is Ga1−xMnxAs (0.04<x<0.07) with Curie temperatures up to 170 K. However, the origin of the ferromagnetic properties is still far from clear.
We investigated the electronic structure of Ga1−xMnxAs using hard x-ray photoelectron spectroscopy (HX-PES). For analysing the intrinsic physical properties it is on the one hand essential to remove any surface oxides and adsorbates, since PES is a comparable surface sensitive technique. On the other hand, bulk information can be increased significantly by performing PES in the hard x-ray regime.
Wet chemical etching was used to clean the surface. This technique widely used in the semiconductor industry yields surfaces with controllable roughness and preserved stoichiometry. The samples were etched either in HCl or H2SO4 followed by rinsing with deionized water. Information on the depth profile of the composition was gained by measurements under different emission angles at a photon energy of 4.5 keV. Results on all relevant core levels and the valence band depending on the chemical treatment are presented.