Concentration and Strain Fields inside a Ag/Au Core–Shell Nanowire Studied by Coherent X-ray Diffraction

Abstract

Three-dimensional coherent diffraction patterns of an isolated, single-crystalline Ag/Au core-shell nanowire were recorded at different X-ray beam energies close to the Au LIII absorption edge. Two-dimensional slices of the three-dimensional diffraction pattern, with the diffraction vector oriented perpendicular to the wire axis, were investigated in detail. In reciprocal space, facet streaks with thickness fringes were clearly observed in the two-dimensional diffraction patterns, from which the shape and size of the corresponding cross sections of the nanowire could be revealed. Comparison with simulated diffraction patterns exhibited the coherency strain field in the nanowire. During in situ annealing at temperatures which would lead to significant intermixing by volume diffusion in bulk material, according to literature data, a core-shell morphology was preserved; that is, intermixing in the nanowire was pronouncedly decelerated compared to bulk diffusion.

Non-destructive detection of cross-sectional strain and defect structure in an individual Ag five-fold twinned nanowire by 3D electron diffraction mapping

“…In the past decade, synchrotron-based coherent x-ray diffraction has exhibited a dramatic progress in non-destructively probing the strain field of nanoparticals 20–22 and nanowires 23–29 . Based on the quantitative analysis of the diffraction intensity distribution, coherent x-ray diffraction has determined the axial and radial strain inside semiconductor or metallic core-shell nanowires 23, 27, 28 , as well as the cross-sectional strain within noble metal five-fold twinned nanowires 29 . Generally, x-ray diffraction only provides an average of the structural information about a bunch of nanostructures.…”

Multi-wavelength Bragg coherent X-ray diffraction imaging of Au particles

“…It shows the presence of a strained layer on top of the Au island. This carbon deposition may originate either from the cracking of hydrocarbons by photoelectrons emitted from the nano-object, which was also reported for Au nanowires (Shin et al, 2018) and for Ag/Au core-shell nanowires (Haag et al, 2013), or from residuals of the photoresist used for the lithographic patterning, which is carbonized by the X-ray beam. S2) that is deposited on top of the Au particle by the highly focused and intense X-ray beam during the measurement.…”

Coherent X‐Ray Diffraction Imaging and Characterization of Strain in Silicon‐on‐Insulator Nanostructures

“…With the ability to achieve quantitative 3D imaging of lattice strain on the nanometer scale, BCDI is becoming a powerful technique for the structural characterization of nano materials and devices. A wide range of applications has been exploited based on the BCDI technique, typical examples including the studying of nanocrystals, nanowires, catalyst microcrystals, materials under high pressure, lattice dynamics and examination of the diffusion behaviors inside nanocrystals, among others, by analyzing the structure, defect and strain either in the static or dynamic process. In the following section, we will focus on the progress on the strain distribution investigation in strained‐silicon‐on‐insulator structures, in which the strain plays a critical role in enhancing device performance.…”