Combined Fitting of Small- and Wide-Angle X-ray Total Scattering Data from Nanoparticles: Benefits and Issues
Igor Levin, Anton Gagin, Andrew J. Allen
Simultaneous fitting of small- and wide-angle total X-ray scattering data for nanoparticles has been explored using both simulated and experimental signals. The nanoparticle types included core/shell metal and quantum-dot CdSe systems. Explicit incorporation of the small-angle scattering (SAS) data in the fit consistently returned more accurate particle-size distribution parameters than those obtained by fitting the wide-angle scattering (WAS) data alone. In particular, a popular method for fitting the Fourier transform of the WAS data (i.e. a pair-distribution function), in which the omitted SAS part is represented using a parametric function, typically yielded significantly incorrect results. The Pareto optimization method combined with a genetic algorithm has been shown effective for combined fitting of the SAS and WAS data. We proposed an approach for identifying the most optimal solution from the Pareto set.
, Gagin, A.
and Allen, A.
Combined Fitting of Small- and Wide-Angle X-ray Total Scattering Data from Nanoparticles: Benefits and Issues, Journal of Applied Crystallography, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=914719
(Accessed February 21, 2024)