scholarly journals Anisotropic and heterogeneous dynamics in an aging colloidal gel

Soft Matter ◽  
2020 ◽  
Vol 16 (11) ◽  
pp. 2864-2872
Author(s):  
Avni Jain ◽  
Florian Schulz ◽  
Irina Lokteva ◽  
Lara Frenzel ◽  
Gerhard Grübel ◽  
...  

We investigate the out-of-equilibrium dynamics of a colloidal gel obtained by quenching a suspension of soft polymer-coated gold nanoparticles close to and below its gelation point using X-ray Photon Correlation Spectroscopy (XPCS).

2015 ◽  
Vol 1754 ◽  
pp. 141-146
Author(s):  
Michael Widera ◽  
Uwe Klemradt

ABSTRACTThrough undulator sources at 3rd generation synchrotrons, highly coherent X-rays with sufficient flux are nowadays routinely available, which allow carrying over photon correlation spectroscopy (PCS) from visible light to the X-ray regime. X-ray photon correlation spectroscopy (XPCS) is based on the auto-correlation of X-ray speckle patterns during the temporal evolution of a material and provides access both to equilibrium and non-equilibrium properties of materials at the Angstrom scale. Owing to technical limitations (detector readout), XPCS has typically been used for the detection of slow dynamics on the scale of seconds. The variety of scattering geometries employed in conventional X-ray analysis can be combined with XPCS. In this work, we report on bulk diffraction (XRD) used to study the prototypical shape memory alloy Ni63Al37 undergoing a structural, diffusionless (martensitic) transformation. Two-time correlation functions reveal non-equilibrium dynamics superimposed with microstructural avalanches.


2018 ◽  
Vol 51 (1) ◽  
pp. 205-209 ◽  
Author(s):  
Ross N. Andrews ◽  
Suresh Narayanan ◽  
Fan Zhang ◽  
Ivan Kuzmenko ◽  
Jan Ilavsky

X-ray photon correlation spectroscopy (XPCS) and dynamic light scattering (DLS) reveal materials dynamics using coherent scattering, with XPCS permitting the investigation of dynamics in a more diverse array of materials than DLS. Heterogeneous dynamics occur in many material systems. The authors' recent work has shown how classic tools employed in the DLS analysis of heterogeneous dynamics can be extended to XPCS, revealing additional information that conventional Kohlrausch exponential fitting obscures. The present work describes the software implementation of inverse transform analysis of XPCS data. This software, calledCONTIN XPCS, is an extension of traditionalCONTINanalysis and accommodates the various dynamics encountered in equilibrium XPCS measurements.


2015 ◽  
Vol 17 (26) ◽  
pp. 16682-16687 ◽  
Author(s):  
Robert M. Karl Jr. ◽  
Andi Barbour ◽  
Vladimir Komanicky ◽  
Chenhui Zhu ◽  
Alec Sandy ◽  
...  

The applied potential dependent rate of atomic step motion of the Ag(001) surface in weak NaF electrolyte has been measured using a new extension of the technique of X-ray Photon Correlation Spectroscopy (XPCS).


2011 ◽  
Vol 44 (1) ◽  
pp. 200-212 ◽  
Author(s):  
F. Zhang ◽  
A. J. Allen ◽  
L. E. Levine ◽  
J. Ilavsky ◽  
G. G. Long ◽  
...  

This paper describes the development of ultra-small-angle X-ray scattering–X-ray photon correlation spectroscopy (USAXS–XPCS). This technique takes advantage of Bonse–Hart crystal optics and is capable of probing the long-time-scale equilibrium and non-equilibrium dynamics of optically opaque materials with prominent features in a scattering vector range between those of dynamic light scattering and conventional XPCS. Instrumental parameters for optimal coherent-scattering operation are described. Two examples are offered to illustrate the applicability and capability of USAXS–XPCS. The first example concerns the equilibrium dynamics of colloidal dispersions of polystyrene microspheres in glycerol at 10, 15 and 20% volume concentrations. The temporal intensity autocorrelation analysis shows that the relaxation time of the microspheres decays monotonically as the scattering vector increases. The second example concerns the non-equilibrium dynamics of a polymer nanocomposite, for which it is demonstrated that USAXS–XPCS can reveal incipient dynamical changes not observable by other techniques.


2021 ◽  
Vol 11 (13) ◽  
pp. 6179
Author(s):  
Felix Lehmkühler ◽  
Wojciech Roseker ◽  
Gerhard Grübel

X-ray photon correlation spectroscopy (XPCS) enables the study of sample dynamics between micrometer and atomic length scales. As a coherent scattering technique, it benefits from the increased brilliance of the next-generation synchrotron radiation and Free-Electron Laser (FEL) sources. In this article, we will introduce the XPCS concepts and review the latest developments of XPCS with special attention on the extension of accessible time scales to sub-μs and the application of XPCS at FELs. Furthermore, we will discuss future opportunities of XPCS and the related technique X-ray speckle visibility spectroscopy (XSVS) at new X-ray sources. Due to its particular signal-to-noise ratio, the time scales accessible by XPCS scale with the square of the coherent flux, allowing to dramatically extend its applications. This will soon enable studies over more than 18 orders of magnitude in time by XPCS and XSVS.


2020 ◽  
Vol 53 (19) ◽  
pp. 8233-8243
Author(s):  
Ronald M. Lewis ◽  
Grayson L. Jackson ◽  
Michael J. Maher ◽  
Kyungtae Kim ◽  
Suresh Narayanan ◽  
...  

2014 ◽  
Vol 2 ◽  
pp. 73-94 ◽  
Author(s):  
Markus Stana ◽  
Manuel Ross ◽  
Bogdan Sepiol

The new technique of atomic-scale X-ray Photon Correlation Spectroscopy (aXPCS) makesuse of a coherent X-ray beam to study the dynamics of various processes in condensed matter systems.Particularly atomistic migration mechanisms are still far from being understood in most of intermetallicalloys and in amorphous systems. Special emphasis must be given to the opportunity to measureatomistic diffusion at relatively low temperatures where such measurements were far out of reach withpreviously established methods. The importance of short-range order is demonstrated on the basis ofMonte Carlo simulations.


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