High-resolution chemical imaging of gold nanoparticles using hard x-ray ptychography

Abstract

We combine resonant scattering with (ptychographic) scanning coherent diffraction microscopy to determine the chemical state of gold nanoparticles with high spatial resolution. Ptychographic images of the sample are recorded for a series of energies around the gold L3 absorption edge. From these data, chemical information in the form of absorption and resonant scattering spectra is reconstructed at each location in the sample. For gold nanoparticles of about 100 nm diameter, a spatial resolution of about 20–30 nm is obtained. In the future, this microscopy approach will open the way to operando studies of heterogeneous catalysts on the nanometer scale.

PtyNAMi: Ptychographic Nano-Analytical Microscope at PETRA III: interferometrically tracking positions for 3D x-ray scanning microscopy using a ball-lens retroreflector

“…26,27,[29][30][31] The instrument served as a test bench for developments of methods and instrumentation in x-ray microscopy, pushing ptychography to high-resolution 15 and sensitivity 32 and combining the technique with resonant scattering to obtain chemical contrast. 33 Ptychography was used to characterize various x-ray optics, including refractive optics like adiabatically focusing lenses (AFL), 34,35 refractive lamellar lenses (RLL), 36 and kinoform lenses, 24 and diffractive optics, such as multilayer Laue lenses (MLL) 22,25 and Fresnel zone plates (FZP). 23 To this end, optics characterization schemes 37, 38 and a way to design corrective phase plates for x-ray optics were developed.…”

DESY NanoLab

“…Today's third generation and future di raction limited synchrotron radiation facilities allow experiments with nano-focused X-ray beams such as single object nano di raction and imaging (Hoppe et al, 2013;Pfeifer et al, 2006). These demanding experiments require involved pre-and post-experimental sample preparation and characterization with complementary techniques.…”

Monitoring dynamic electrochemical processes with in situ ptychography

“…Fresnel-CDI methods based on FZPs are specially suitable for in situ work-in which the precise localization of the active interface is vital-since a real-time holographic image gives the possibility of pre-selecting the region of interest in the direct space, thus combining the advantages of direct and Fourier imaging modes (Bozzini et al 2017a). Moreover, ptychography can provide space-resolved chemical-state information through the phase and amplitude maps recovered by scanning the photon energy across elemental resonances (Hoppe et al 2013;Maiden et al 2013;Kourousias et al 2016;Bozzini et al 2017b;Pfeiffer 2018).…”