Krumme, B., Weis, C., Herper, H. C., Stromberg, F., Antoniak, C., Warland, A., Schuster, E., Srivastava, P., Walterfang, M., Fauth, K., Minar, J., Ebert, H., Entel, P., Keune, W., Wende, H.
Local atomic order and element-specific magnetic moments of Fe3Si thin films on MgO(001) and GaAs(001) substrates
Physical Review B 80, (14),pp 144403/1-8 (2009)
We investigated the magnetic as well as the structural properties of Fe3Si films on GaAs(001)-(4x6), GaAs(001)-(2x2), and MgO(001) by x-ray magnetic circular dichroism (XMCD) and Mössbauer spectroscopy. From the XMCD spectra we determine averaged magnetic moments of 1.3-1.6 μB per Fe atom on the different substrates by a standard sum-rule analysis. In addition, XMCD spectra have been calculated by using the multiple-scattering Korringa-Kohn-Rostoker method which allows the site-specific discussion of the x-ray spectra. The Mössbauer spectra show a highly ordered and stoichiometric growth of Fe3Si on MgO while the growth on both GaAs substrates is strongly perturbed, probably due to diffusion of substrate atoms into the Fe3Si film. Therefore, we have studied the influence of Ga or As impurities on the magnetic properties of Fe3Si by calculations using coherent-potential approximation within the Korringa-Kohn-Rostoker method. For selected impurity concentrations additional supercell calculations have been performed using a pseudopotential code (VASP).