Regensburg 2000 – wissenschaftliches Programm
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AM: Magnetismus
AM 13: Postersitzung: Dünne Schichten (1–22), Magnetowiderstand (23–40), Phasenübergänge (41–55), Mikromagnetismus (56–68), Spektroskopie (69–77), Nanokristalline Materialien (78–82), Anisotropie (83–86), Schmelzen (87–90), Weitere Bereiche (91–100)
AM 13.4: Poster
Dienstag, 28. März 2000, 16:00–20:00, A
Structure and magnetism of epitaxial Fe/GaAs(001) — •B. Roldán Cuenya1, M. Walterfang1, W. Keune1, T. Schmitte2, A. Nefedov2, H. Zabel2, J. Koch3, and A. Wieck3 — 1Angew. Physik,Uni. Duisburg, 47048 Duisburg — 2Experimentalphysik/Festkörperphysik, Ruhr-Uni. Bochum,44780 Bochum — 3Angew. Festkörperphysik, Ruhr-Uni. Bochum,44780 Bochum
We have grown by MBE Fe(001) films on As depleted GaAs(001) surfaces held near room temperature. RHEED and AES studies revealed the clean and atomically flat As depleted (4x6) GaAs(001) surface. RHEED demonstrated good epitaxial 3D-type growth of 70Å thick layers, either of natural Fe or enriched 57Fe. Films were coated by 42Å of Sn and investigated ex-situ by Mössbauer effect (CEMS and DCEMS), X-ray reflectometry, and longitudinal MOKE. Mössbauer spectra have been analyzed in terms of three subspectra: a sextet due to bulk-like bcc Fe, a distribution of hyperfine magnetic fields assigned to the intermixed magnetic Fe/GaAs interface, and a central quadrupole-split doublet caused by a non-magnetic Fe-Sn interface alloy. Simulations of the depth profile of the three spectral components could well describe the DCEMS results.The depth distribution of the various phases as obtained from simulations of the X-ray reflectometry data are in good agreement with the DCEMS depth profiles. All samples show ferromagnetic MOKE hysteresis loops. Within the film plane 4-fold (2-fold) magnetic anisotropy was observed for samples with a thinner (thicker) Fe/GaAs interface.
Work supported by Deutsche Forschungsgemeinschaft.