AVS 45th International Symposium
    Surface Science Division Thursday Sessions
       Session SS-ThP

Paper SS-ThP13
The Surface Structure Determination of @alpha@-Fe@sub 2@O@sub 3@(0001) by Low-Energy X-Ray Photoelectron Diffraction

Thursday, November 5, 1998, 5:30 pm, Room Hall A

Session: Surface Science Division Poster Session
Presenter: S. Thevuthasan, Pacific Northwest National Laboratory
Authors: S. Thevuthasan, Pacific Northwest National Laboratory
Y.J. Kim, Pacific Northwest National Laboratory
S.A. Chambers, Pacific Northwest National Laboratory
J. Morais, Lawrence Berkeley National Laboratory
R. Denecke, Lawrence Berkeley National Laboratory
C.S. Fadley, Lawrence Berkeley National Laboratory
P. Liu, Stanford University
T. Kendelewicz, Stanford University
D.E. Brown Jr., Stanford University
Correspondent: Click to Email
The structure and composition of oxide surfaces strongly influence the chemical and mechanical properities of these materials. As such, there is a growing interest of determining surface termination, reconstruction and relaxation on these surfaces. Recent theoretical work by Wasserman et. al [1] have shown that hematite(@alpha@-Fe@sub 2@O@sub 3@(0001)) surface has a single Fe layer termination with relaxations in the first four planes of -49%, -3%, -41%, and 21% of the bulk values respectively. We recently performed x-ray photoelectron diffraction measurements at Advanced Light Source on a clean, epitaxially grown Fe@sub 2@O@sub 3@(0001)/Al@sub 2@O@sub 3@(0001). A photon energy of 400 eV (Fe 3p E@sub kin@ = 344 eV) was used to collect several Fe 3p azimuthal scans at different take off angles. The experimental data were compared to the theoretical simulations using single and multiple scattering calculations with trial geometries. R-factors were calculated and minimized to obtain the optimum geometry. The surface appears to be Fe-terminated and the first four layer spacing are -41%, +18%, -8%, and 47% of the associated bulk values, respectively. @FootnoteText@ Work supported by the U.S. Department of Energy (DOE), Office of Basic Energy Sciences and Biological and Environmental Research Environmental Management ScienceProgram