Regensburg 2007 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 20: Magnetic Thin Films II

MA 20.13: Vortrag

Mittwoch, 28. März 2007, 18:15–18:30, H5

Real time optical monitoring of ultrathin magnetic film growth on Cu(110) — •Richard Denk, Michael Hohage, L.D. Sun, and Peter Zeppenfeld — Institut für Experimentalphysik, Johannes Kepler Universtät Linz, A-4040 Linz, Austria

Reflectance Difference Spectroscopy (RDS) has been used to monitor the growth of thin Ni films on Cu(110)(2x1)O and to characterise them. Whereas the regular optical anisotropy signal originates from the morphology of the film, the RD-spectrometer may sense additionally the out of plane magnetisation of the film via polar Magneto-Optical Kerr Effect (MOKE) [1]. The RD-spectrometer allows conducting spectroscopic measurements of the films at photon energies between 1.5 eV and 5.5 eV. To perform the magnetic measurements the UHV chamber is equipped with an in-situ electromagnet. As the magnetic signal is superimposed onto the regular anisotropy signal, applying the RD-technique at opposite magnetisation (M⁺,M⁻) of the film, the pure RDS signal (Δr/r(M⁺) + Δr/r(M⁻))/2 can be separated from the MOKE signal (Δr/r(M⁺) - Δr/r(M⁻))/2. Using RD- transients at a fixed wavelength hysteresis curves at any desired photon energy between 1.5 eV and 5.5 eV can be recorded. For film characterization, in addition to RDS, the chamber is equipped with a STM and a LEED/AES system. A major focus of the study has been the effect of adsorption on the magnetic properties of ultrathin Ni films, as well as the way how the remanent polar magnetisation develops within the ultrathin Ni films. References [1] M. Wahl, Th. Herrmann, N. Esser, and W. Richter, phys. stat. sol. c, 3002 (2003)