Hostname: page-component-78c5997874-m6dg7 Total loading time: 0 Render date: 2024-11-10T21:30:41.876Z Has data issue: false hasContentIssue false
  • English
  • Français

Convergent-Beam Low Energy Electron Diffraction (CBLEED) and the Measurement of Surface Dipole Layers

Published online by Cambridge University Press:  22 January 2004

J.C.H. Spence ,
H.C. Poon  and
D.K. Saldin
J.C.H. Spence
Affiliation:
Department of Physics and Astronomy, College of Liberal Arts and Science, Arizona State University, Tempe, AZ 85287-1504, USA
H.C. Poon
Affiliation:
Department of Physics and Laboratory for Surface Studies, University of Wisconsin-Milwaukee, Milwaukee, WI 53211, USA
D.K. Saldin
Affiliation:
Department of Physics and Laboratory for Surface Studies, University of Wisconsin-Milwaukee, Milwaukee, WI 53211, USA
Get access

Abstract

We propose the formation of LEED patterns using a highly convergent beam forming a probe of nanometer dimensions. A reflection rocking curve may then be recorded in many diffraction orders simultaneously. Multiple scattering calculations show that the intensity variations within these rocking curves is as sensitive to the parameters describing the surface dipole layer as conventional I/V scans. However the data may be collected from areas sufficiently small to avoid defects and surface steps, radiation damage controlled by use of low voltages, and the information depth selected by choice of the (constant) voltage. We briefly discuss also the application of this method to oxides and the formation of atomic-resolution scanning images in an idealized instrument in which coherent diffracted LEED orders overlap.

Keywords

LEEDconvergent beamnanoprobedipole layer
Type
Research Article
Information
Microscopy and Microanalysis , Volume 10 , Issue 1 , February 2004 , pp. 128 - 133
Copyright
© 2004 Microscopy Society of America

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Firment, L. & Somorjai, G. (1979). Low energy electron diffraction studies of the surfaces of molecular crystals. Surf Sci 84, 275–283.CrossRefGoogle Scholar
Ichimiya, A., Kambe, K., & Lehmpfuhl, G. (1980). Observation of the surface state resonance by the CBED RHEED technique. J Phys Soc Jpn 49, 684–688.CrossRefGoogle Scholar
Jones, R.O., Jennings, P.J., & Jepson, O. (1984). Surface barrier in metals: A new model with application to W(001). Phys Rev B 29, 6474–6479.CrossRefGoogle Scholar
O'Keeffe, M.A. & Spence, J.C.H. (1993). On the average coulomb potential and constraints on the electron density in crystals. Acta Cryst A 50, 33–45.Google Scholar
Pendry, J.B. (1974). Low Energy Electron Diffraction. London: Academic Press.
Peng, L.M., Dudarev, S., & Whelan, M. (1998a). Electron scattering factors for ions and dynamical RHEED surfaces of ionic crystals. Phys Rev B 57, 7259–7263.Google Scholar
Peng, L.M., Zuo, J.M., & Spence, J.C.H. (1998b). RHEED studies of the surfaces of ionic crystals. In Proceedings of the International Congress on Electron Microscopy, Electron Microscopy 1998 H.A. Calderon Benavides & M.J. Yacaman (Eds.), Vol. 3, p. 685. Bristol: Institute of Physics. Cancun.
Poon, H.C., Tong, S.Y., Chung, W., & Altman, M. (1998). LEED analysis of Ag on W(110). Surf Rev Lett 5, 1143–1149.CrossRefGoogle Scholar
Saldin, D. & Spence, J. (1994). On the mean inner potential in high and low energy electron diffraction. Ultramicroscopy 55, 397–406.CrossRefGoogle Scholar
Slater, J.C. (1967). Insulators, Semiconductors and Metals. New York: McGraw Hill.
Spence, J.C.H. & Cowley, J.M. (1978). Lattice imaging in STEM. Optik 50, 129–138.Google Scholar
Spence, J.C.H. & Zuo, J.M. (1992). Electron Microdiffraction. New York: Plenum.CrossRef
Tan, C. & Cowley, J. (1984). Surface potential study of Au(111). Ultramicroscopy 12, 333–339.Google Scholar
Van Hove, M.A. & Tong, S.Y. (1979). Surface Crystallography by LEED. Berlin: Springer-Verlag.CrossRef
Venables, J. (2002). Introduction to Surface and Thin Film Processes. New York: Cambridge University Press.
Yamamoto, N. & Spence, J.C.H. (1983). Surface imaging of semiconductors by reflection electron microscopy and inner potential measurements. Thin Solid Films 104, 43–55.CrossRefGoogle Scholar
Zangwill, A. (1988). Physics at Surfaces. Cambridge: Cambridge University Press.CrossRef
Zhao, T.C., Poon, H.C., & Tong, S.Y. (1988). Invariant-embedding R-matrix scheme for reflection high-energy electron diffraction. Phys Rev B 38, 1172–1188.CrossRefGoogle Scholar
Zuo, J.M., Kim, M., O'Keeffe, M., & Spence, J.C.H. (1999). Observation of d holes and Cu-Cu bonding in cuprite. Nature 401, 49–52.CrossRefGoogle Scholar
Zuo, J.M., Weierstall, U., Peng, L.M., & Spence, J.C.H. (2000). Surface sensitivity of CB-RHEED: Si (001) 2x1 models compared with dynamical simulations. Ultramicroscopy 81, 235–244.CrossRefGoogle Scholar