High-accuracy transmission and fluorescence XAFS of zinc at 10 K, 50 K, 100 K and 150 K using the hybrid technique

Abstract
The most accurate measurements of the mass attenuation coefficient for metals at low temperature for the zinc K-edge from 9.5 keV to 11.5 keV at temperatures of 10 K, 50 K, 100 K and 150 K using the hybrid technique are reported. This is the first time transition metal X-ray absorption fine structure (XAFS) has been studied using the hybrid technique and at low temperatures. This is also the first hybrid-like experiment at the Australian Synchrotron. The measured transmission and fluorescence XAFS spectra are compared and benchmarked against each other with detailed systematic analyses. A recent method for modelling self-absorption in fluorescence has been adapted and applied to a solid sample. The XAFS spectra are analysed using eFEFFIT to provide a robust measurement of the evolution of nanostructure, including such properties as net thermal expansion and mean-square relative displacement. This work investigates crystal dynamics, nanostructural evolution and the results of using the Debye and Einstein models to determine atomic positions. Accuracies achieved, when compared with the literature, exceed those achieved by both relative and differential XAFS, and represent a state-of-the-art for future structural investigations. Bond length uncertainties are of the order of 20–40 fm. © Open Access - CC BY 4.0 licence
Description
We gratefully acknowledge the collaboration with Zwi Barnea who drove the investigation of Zn. Some of this research was undertaken on the XAS beamline at the Australian Synchrotron, part of ANSTO. We thank beamline scientists at the Australian Synchrotron for their support and dedication to build up part of this methodology. We thank the synchrotron team, including Jeremy Wykes, Chris Glover and Susan Cumberland.
Keywords
X-ray spectroscopy, Transmission, Fluorescence, Zinc, Metals, Temperature range 0065-0273 K, Debye length, Bond lengths, Thermal expansion
Citation
John, M. W., Sier, D., Ekanayake, R. S. K., Schalken, M. J., Tran, C. Q., Johannessen, B., de Jonge, M. D., Kappen, P., & Chantler, C. T. (2023). High-accuracy transmission and fluorescence XAFS of zinc at 10 K, 50 K, 100 K and 150 K using the hybrid technique. Journal of Synchrotron Radiation, 30(1), 147-168. doi:10.1107/S1600577522010293
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