EXAFS and Near Edge Structure IV
J. Phys. Colloques 47 (1986) C8-55-C8-62
DOI: 10.1051/jphyscol:1986808
IMPROVED DETERMINATION OF BACKSCATTERING AMPLITUDE AND PHASE SHIFT FUNCTIONS
A.G. McKALE1, S.-K. CHAN2, B.W. VEAL2, A.P. PAULIKAS2 et G.S. KNAPP31 Also at the Department of Physics and Astronomy, Northwestern University, Evanston, IL 60201. Work performed at Argonne National Laboratory while a Laboratory-Graduate Thesis Program Participant. Program administered by the Argonne Division of Educational Programs with funding from the U.S. Department of Energy.
2 Materials Science Division, Argonne National Laboratory, Argonne, IL 60439, U.S.A.
3 Surface Science Laboratories, 465 National Avenue, Mountain View, CA 94043, U.S.A.
Abstract
Procedures for analysis of EXAFS data require knowledge of the phase shift and amplitude functions, Φ(k) and B(k). We present procedures to obtain these functions, both experimentally and theoretically, that overcome limitations in presently available methods. A procedure is described that allows for the use of crystallographically complex materials to serve as standards in the experimental determination of Φ(k) and B(k). Also we present a convenient algorithm, that uses the full curved wave formalism, to determine the functions theoretically. Improved results are obtained, particularly at low k. We illustrate the use of these procedures with a study of the 3d transition metals.