AVS 52nd International Symposium
    Magnetic Interfaces and Nanostructures Wednesday Sessions
       Session MI-WeM

Invited Paper MI-WeM9
Medard Welch Award Lecture: Studies of Magnetic Materials and Nanostructures using Synchrotron Radiation Spectroscopy, Diffraction, and Holography

Wednesday, November 2, 2005, 11:00 am, Room 204

Session: Magnetic Imaging and Spectroscopies
Presenter: C. Fadley, University of California, Davis and LBNL, Berkeley
Correspondent: Click to Email
I will discuss several recent developments in studies of magnetic surfaces and magnetic nanostructures using synchrotron radiation, with special emphasis on work in the soft x-ray regime at the Berkeley Advanced Light Source. Instrumentation that has been developed to carry out multiple spectroscopies with varying degrees of surface sensitivity (photoemission, x-ray absorption, and x-ray emission) on a single sample will be introduced, together with future prospects in photoemission based on higher-speed detection.@footnote 1@ Then a new standing wave-plus-wedge method for non-destructively studying buried interfaces in multilayer nanostructures will be considered.@footnote 2@ This method has permitted determining concentration and magnetization profiles through an Fe/Cr giant magnetoresistive interface,@footnote 2a@ as well as layer-specific densities of states in a magnetic tunnel junction consisting of FeCoB/FeCo/Al@sub 2@O@sub 3@.@footnote 2c@ This approach should also be useful in a variety of other interface studies,@footnote 2b@ with the use of soft x-ray detection permitting the study of more deeply buried interfaces.@footnote 2d@ Application of the multi-spectroscopy experimental system to the colossal magnetoresistive oxide materials La@sub 1-x@Sr@sub x@MnO@sub 3@ (x = 0.3, 0.4) will also be discussed, including the direct observation of charge localization on Mn in polaron formation@footnote 3a@ and surface stoichiometry characterization.@footnote 3b@ Finally, the prospects for element-specific determinations of local atomic and magnetic structure using photoelectron holography will be considered.@footnote 4@ Work supported by the Dept. of Energy, Basic Energy Sciences, Materials Science and Engineering Division, under Contract DE-AC03-76SF00098. @FootnoteText@ @Footnote 1@J.-M. Bussat, C.S. Fadley, B.A. Ludewigt, G.J. Meddeler, A. Nambu, M. Press, H. Spieler, B. Turko, M. West, G.J. Zizka, IEEE Transactions on Nuclear Science 51, 2341 (2004), with further details at: http://www.physics.ucdavis.edu/fadleygroup. @footnote 2a@S.-H. Yang, B.S. Mun, N. Mannella, S.-K. Kim, J.B. Kortright, J. Underwood, F. Salmassi, E. Arenholz, A. Young, Z. Hussain, M.A. Van Hove, and C.S. Fadley, J. Phys. Cond. Matt. 14, L406 (2002) @footnote 2b@S.-H. Yang, B.S. Mun, and C.S. Fadley, Synchrotron Radiation News 17 (3), 24 (2004) @footnote 2c@S.-H. Yang, B.S. Mun, et al., to be published @footnote 2d@M. Watanabe, B.C. Sell, et al. to be published. @footnote 3a@N. Mannella, A. Rosenhahn, C. H. Booth, S. Marchesini, B. S. Mun, S.-H. Yang, K. Ibrahim, Y. Tomioka, and C.S. Fadley, Phys. Rev. Lett. 92, 166401 (2004) @footnote 3b@N. Mannella et al., to be published. @footnote 4@C.S. Fadley, M.A. Van Hove, A. Kaduwela, S. Omori, L. Zhao, and S. Marchesini, J. Phys. Cond. Mat. 13, 10517 (2001)