High-accuracy determination of photoelectric cross sections, X-ray absorption fine structure and nanostructure analysis of zinc selenide using the X-ray extended range technique
Loading...
Date
2021-08-14
Journal Title
Journal ISSN
Volume Title
Publisher
International Union of Crystallography
Abstract
Measurements of mass attenuation coefficients and X-ray absorption fine structure (XAFS) of zinc selenide (ZnSe) are reported to
accuracies typically better than 0.13%. The high accuracy of the results presented here is due to our successful implementation of the
X-ray Extended Range Technique (XERT), a relatively new methodology, which can be set up on most synchrotron X-ray beamlines.
561 attenuation coefficients were recorded in the energy range of 6.8 keV to 15 keV that was independently calibrated using powder
diffractometry, with measurements concentrated at the zinc and selenium pre-edge, near edge and fine structure absorption edge
regions. The removal of systematic effects as well as coherent (Thermal Diffuse) and incoherent (Compton) scattering processes
produced very high accuracy values of photoelectrc attenuation which in turn yielded a detailed nanostructural analysis of room
temperature ZnSe with full uncertainty propagation. Bond lengths, accurate to 0.003 Å to 0.009 Å, or 0.1% to 0.3%, are plausible and
physical. Small variation from a crystalline structure suggests local dynamic motion beyond that of a standard crystal lattice, noting
that XAFS is sensitive to dynamic correlated motion. The results obtained in this work are the most accurate to date with comparisons
to theoretically determined values of the attenuation showing discrepancies from literature theory of up to 4%, motivating further
investigation into the origin of such discrepancies. © The Authors
Description
Keywords
Fine structure, Scattering, Cyrstal structure, Zinc selenides, Diffraction, Attenuation
Citation
Sier, D., Cousland, G. P., Trevorah, R. M., Ekanayake, R. S. K., Tran, C. Q., Hester, J. R., & Chantler, C. T. (2021). High-accuracy determination of photoelectric cross sections, X-ray absorption fine structure and nanostructure analysis of zinc selenide using the X-ray extended range technique. Poster presented to the IUCr 2021, 25th Congress of the International Union of Crystallography, 14-22 August 2021, Prague, Czech Republic. In Acta Crystallographica Section A: Foundations and Advances, 77(a2), C1271. doi:10.1107/S0108767321084439