Regensburg 2019 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 34: New Methods and Developments III: Spectroscopy and Tribology

O 34.5: Vortrag

Dienstag, 2. April 2019, 15:00–15:15, H13

Projection Analysis of EXAFS Modulations — Alireza Bayat¹, Angelika Chassé¹, Reinhard Denecke², Stefan Förster¹, Paula Huth², Eva-Maria Zollner¹, and •Karl-Michael Schindler¹ — ¹Martin-Luther-Universität Halle-Wittenberg, Institut f. Physik, D-06099 Halle, Germany — ²Wilhem-Ostwald-Institut f. Physikalische und Theoretische Chemie, D-04103 Leipzig, Germany

EXAFS modulations have been analysed using a direct projection method known from structure determinations using photoelectron diffraction [1]. In this method experimental EXAFS modulations are projected onto calculated ones with just one singular neighbouring atom at a series of distances. Compared to the usual analysis with a Fourier transform of the EXAFS modulation function, the systematic errors in initial values for nearest neighbor distances are significantly reduced from 40 - 80 pm to below 10 pm. This improvement results from the correct treatment of the energy dependence of the phase shift within the scattering process at the neighboring atom. Tests of the method are presented with experimental EXAFS modulations from strontium titanate and barium titanate single crystals as well as from a newly discovered barium titanate derived quasicrystalline film on a Pt(111) substrate [2].

References:

[1] P. Hofmann and K.-M. Schindler, Phys. Rev. B 47, 13941 (1993).

[2] S. Förster et al., Nature 502, 215 (2013).