Abstract
Spin polarized low energy electron microscopy (SPLEEM) has been developed for the high resolution imaging of surface magnetic structure. The existing LEEM ha.s been modified by the incorporation of a. GaAs-type spin polarized electron gun. Large image contrast arises due to the spin-dependent exchange scattering, whifle the st.in-orbit contribution vanishes uniquely for the normal incidence/exit geometry used here. Pixel by pixel image subtraction for incident electron beams of opposite polarization yields precisely the spatially resolved Bragg reflection asymmetry observed in spin polarized low energy electron diffraction. The shallow electron penetration depth arising from the strong coulombic interaction is advantageous for separating surface behavior from the normally overwhelning bulk. Therefore, the use of transversally polarizedI electron beams allows the determination of in-plane surface magnetization directions. Fnrthermore, the parallel illumination and detection of SPLEEM makes it possible to image quickly with a. resolution better than 500 Å in the present configuration. A useful and direct. comparison between surface magnetic, structural, and topological features is made possible by the augmentation of the unique imaging capabilities of conventional LEEM with the magnetic sensitivity of SPLEEM. In this manner, the magnetic domain structure of a Co (0001) surface and in-situ grown Co filmns on Mo(110) have been determined.
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References
J. Kirschner, Polarized Electrons at Surfaces (Springer-Verlag, Berlin, 1985).
R.. Feder, edit.: Polarized Electrons in Surface Physics (World Scientific, Singapore, 1985).
P.D. Johnson, A. Clarke, N.B. Brookes, S.L. Hulbert, B. Sinkovic, and N.V. Smith, Phys. Rev. Lett. 61, 2257 (1988).
M. Donath, Appl. Phys. A 49, 351 (1989).
E. Tamura. and R.. Feder, Phys. R.ev. Lett. 57, 759 (1986).
R. Allenspach, M. Taborelli, amnd M. Landolt, Phys. Rcv. Lett. 55, 2599 (1985).
G.A. Mulhollan, A.R. Köymen, D.M. Lind, F.B. Bunning, G.K. Walters, E. Tamura, and R. Feder, Surf. Sci. 204, 503 (1988).
J. Kirschner, Phys. Rev. B 30, 415 (1984).
J. Kirschner, Surf. Sci. 138, 191 (1984).
D. Weller, S.F. Alvarado, W. Gudat, K. SchrOuml;der, and M. Campagna, Phys. Rev. Lett. 54, 1555 (1985).
M. Hartmann, J.Mag.Mag.Mat. 68, 298 (1987).
I.R.. McFayden, J. Appl. Phys. 64, 6011 (1988).
D.E. Newbury and H. Yakowiitz, in Practical Scanning Electron Microscopy, edited by J.I. Goldstein and H. Yakowitz (Plenum Press, New York, 1975), p. 180.
H. Mayer, J. Appl. Phys. 28, 975 (1957).
W. Rave, R. Schafer, and A. Hubert, J. Mag. Mag. Mat. 65, 7 (1987).
H.P. Oepen and J. Kirschner, Phys. Rev. Lett. 62, 819 (1989).
M.R. Scheinfein, J. Unguris, R.J. Cellota, and D.T. Pierce, Phys. Rev. Lett. 63, 668 (1989).
J. Unguris, M.R. Scheinfein, R.J. Celotta., and D.T. Pierce, Appl. Phys. Lett. 55, 2553 (1989).
D.L. Abraham and H. Hopster, Phys. Rev. Lett. 58, 1352 (1987).
R. Allenspach, M. Stampanoni, and A. Bischof, Phys. Rev. Lett. 65, 3344 (1990).
D. Pierce, private communication.
R. Allenspach and A. Bischof, Appl. Phys. Lett. 54, 587 (1989).
D. Rugar, F.J. Mamin, P. Guethner, S.E. Lambert, I. McFadyen, aund T. Yogi, J. Appl. Phys. 68, 1169 (1990).
R. Wiesendanger, H.-J. Güntherodt, G. Güntherodt, amnd R. Ruf, Phys. Rev. Lett. 65, 247 (1990).
E. Bauer, in Chemistry and Physics of Solid Surfaces VIII, edited by R. Vanselow and R. Howe (Springer, Berlin, 1990), p. 267.
D.T. Pierce, R.J. Cellota., G.-C. Wang, W.N. Unertl, A. Galejs, C.E. Kuyatt, and S.R. Mielczarek, Rev. Sci. Instrum. 51, 478 (1978).
M.S. Altman, G. Marx, H. Pinkvos, E. Bauer, J. Hurst, and H. Poppa., to be published.
M. Tikhov and' E. Bauer, Surf. Sci. 232, 73 (1990).
Acknowledgements
We thank Peter Gruetter (IBM ARC) for the Ci crystal. M.S.A. gratefully acknowledges financial support from the Alexander von Humboldt Foundation, Bonn.
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Altman, M.S., Pinkvos, H., Hurst, J. et al. Spin Polarized Low Energy Electron Microscopy of Surface Magnetic Structure. MRS Online Proceedings Library 232, 125–132 (1991). https://doi.org/10.1557/PROC-232-125
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DOI: https://doi.org/10.1557/PROC-232-125