AVS 51st International Symposium
    Magnetic Interfaces and Nanostructures Thursday Sessions
       Session MI-ThM

Paper MI-ThM3
Measuring Spin Polarization at the Fermi Level in Potential Half-Metallic Ferro-magnets

Thursday, November 18, 2004, 9:00 am, Room 304A

Session: Magnetic Oxides and Half-Metallics
Presenter: J.G. Tobin, Lawrence Livermore National Laboratory
Authors: J.G. Tobin, Lawrence Livermore National Laboratory
T. Komesu, University of Missouri-Rolla
G.D. Waddill, University of Missouri-Rolla
Correspondent: Click to Email
We have utilized synchrotron-radiation-based techniques to investigate possibly half-metallic ferromagnetic (HMFM) materials. HMFM’Ts are, of course, potential sources of pure spin polarized electrons for spintronic and magnetic information storage devices. These investigations include the application of spin-resolved photoelectron spectroscopy (SPES) to systems such as Fe3O4@footnote 1@ and X-ray Absorption Spectroscopy (XAS) to Zintl compounds such as Yb14MnSb11. @footnote 2@ In the case of Fe3O4, despite having performed the studies at the relatively high photon energy of 160 eV, significant problems with residual surface effects were observed. In order to circumvent or at least minimize these surface complications and to get a better measure of the true bulk spin polarization, we have moved our spin-resolving spectrometer@footnote 3@ to Beamline 4 at the Advanced Photon Source,@footnote 4@ where an Elliptically Polarizing Undulator (EPU) can provide high brightness radiation in the range of 500 eV to 3000 eV. Our first spin-resolved results of the Fe2p core levels@footnote 5@ have confirmed the feasibility of these experiments. Plans for the interrogation of potential half-metallic ferromagnets such as GaMnAs and related materials at these higher energies will be discussed. @FootnoteText@This work was performed under the auspices of the U. S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under Contract No. W-7405-Eng-48. @footnote 1@ S.A. Morton, G.D. Waddill, S. Kim, I.K. Schuller, S.A. Chambers, and J.G. Tobin, Surface Science Letters 513, L451 (2002). @footnote 2@ A.P. Holm, S.M. Kauzlarich, S.A. Morton, G.D. Waddill, W.E. Pickett, and J.G. Tobin, J. Amer. Chem. Soc. 124, 9894 (2002). @footnote 3@ M. Hochstrasser, J.G. Tobin, E. Rotenberg and S.D. Kevan, "Spin-Resolved Photoemission of Surface States of W(110)-(1X1)H," Phys. Rev. Lett. 89, 216802 (2002). @footnote 4@ J.W. Freeland et al, Rev. Sci. Instrum. 73, 1408 (2002). @footnote 5@ http://www-cms.llnl.gov/s-t/aps.html