Characterizing crystalline defects in single nanoparticles from angular correlations of single-shot diffracted X-rays

Abstract

Characterizing and controlling the uniformity of nanoparticles is crucial for their application in science and technology because crystalline defects in the nanoparticles strongly affect their unique properties. Recently, ultra-short and ultra-bright X-ray pulses provided by X-ray free-electron lasers (XFELs) opened up the possibility of structure determination of nanometre-scale matter with Å spatial resolution. However, it is often difficult to reconstruct the 3D structural information from single-shot X-ray diffraction patterns owing to the random orientation of the particles. This report proposes an analysis approach for characterizing defects in nanoparticles using wide-angle X-ray scattering (WAXS) data from free-flying single nanoparticles. The analysis method is based on the concept of correlated X-ray scattering, in which correlations of scattered X-ray are used to recover detailed structural information. WAXS experiments of xenon nanoparticles, or clusters, were conducted at an XFEL facility in Japan by using the SPring-8 Å ngstrom compact free-electron laser (SACLA). Bragg spots in the recorded single-shot X-ray diffraction patterns showed clear angular correlations, which offered significant structural information on the nanoparticles. The experimental angular correlations were reproduced by numerical simulation in which kinematical theory of diffraction was combined with geometric calculations. We also explain the diffuse scattering intensity as being due to the stacking faults in the xenon clusters.

X-ray induced ultrafast dynamics in atoms, molecules, and clusters: experimental studies at an X-ray free-electron laser facility SACLA and modelling

“…The present findings may validate the 'diffraction-beforedestruction' approach of single bio-macromolecules and protein microcrystals, as long as the hydrogen atoms can be neglected, and also suggest the importance of understanding influences of charge dynamics that occur within the X-ray-pulse duration to the X-ray scattering. We have also been conducting spectroscopic experiments using soft-X-ray FEL [49][50][51] and X-ray diffraction experiments [52][53][54][55] at SACLA, though these attempts were not described in the present review article. We believe that electronic and structural dynamics in various forms of matter will be investigated extensively employing XFELs all over the world and we hope that our attempts described in this article will contribute to such investigations.…”

Angular X-ray cross-correlation analysis applied to the scattering data in 3D reciprocal space from a single crystal

“…Here, we consider the scattered intensity distribution measured by a 2D detector. The conventional AXCCA is based on the analysis of a two-point cross-correlation function (CCF) defined as (Niozu et al, 2020) Cðq 1 ; q 2 ; ÁÞ ¼…”

“…Indeed, each pair of momentum transfer vectors taken in 3D reciprocal space lay in a certain 2D hyperplane that can be thought of as a 2D diffraction pattern. If the number of the randomly oriented 2D patterns is big enough, they cover the whole 3D space and the CCFs averaged over such a set of 2D patterns are identical to the CCFs calculated for the 3D pattern (Niozu et al, 2020). The number of randomly oriented 2D scattering patterns required to obtain the same information as from the 3D scattered intensity distribution is discussed in Section 3.3.…”

“…AXCCA was shown to be useful to extract additional information from the scattering patterns of crystalline samples (Mendez et al, 2016;Niozu et al, 2020). In this case, the scattered intensity contains well defined Bragg peaks originating from the crystallographic planes of the sample.…”

“…To explore the symmetries of a 3D sample, one typically collects many 2D patterns from randomly oriented identical samples, for example, injected bioparticles (Kurta et al, 2017;Pande et al, 2018) or nanocrystals (Mendez et al, 2016;Niozu et al, 2020;Ayyer et al, 2021) as shown in Fig. 1(a).…”