In situ reactor to image catalysts at work in three-dimensions by Bragg coherent X-ray diffraction

2019 ◽  
Vol 336 ◽  
pp. 169-173 ◽  
Author(s):  
Amélie Rochet ◽  
Ana Flávia Suzana ◽  
Aline R. Passos ◽  
Tiago Kalile ◽  
Felisa Berenguer ◽  
...  
2016 ◽  
Vol 23 (5) ◽  
pp. 1241-1244 ◽  
Author(s):  
Wonsuk Cha ◽  
Wenjun Liu ◽  
Ross Harder ◽  
Ruqing Xu ◽  
Paul H. Fuoss ◽  
...  

A method is presented to simplify Bragg coherent X-ray diffraction imaging studies of complex heterogeneous crystalline materials with a two-stage screening/imaging process that utilizes polychromatic and monochromatic coherent X-rays and is compatible within situsample environments. Coherent white-beam diffraction is used to identify an individual crystal particle or grain that displays desired properties within a larger population. A three-dimensional reciprocal-space map suitable for diffraction imaging is then measured for the Bragg peak of interest using a monochromatic beam energy scan that requires no sample motion, thus simplifyingin situchamber design. This approach was demonstrated with Au nanoparticles and will enable, for example, individual grains in a polycrystalline material of specific orientation to be selected, then imaged in three dimensions while under load.


Author(s):  
R. E. Herfert

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.


2017 ◽  
Vol 72 (6) ◽  
pp. 355-364
Author(s):  
A. Kopp ◽  
T. Bernthaler ◽  
D. Schmid ◽  
G. Ketzer-Raichle ◽  
G. Schneider

2020 ◽  
Author(s):  
Chi-Toan Nguyen ◽  
Alistair Garner ◽  
Javier Romero ◽  
Antoine Ambard ◽  
Michael Preuss ◽  
...  

2019 ◽  
Author(s):  
Si Athena Chen ◽  
◽  
Peter Heaney ◽  
Jeffrey E. Post ◽  
Peter J. Eng ◽  
...  

2002 ◽  
Vol 47 (19) ◽  
pp. 3137-3149 ◽  
Author(s):  
M. Morcrette ◽  
Y. Chabre ◽  
G. Vaughan ◽  
G. Amatucci ◽  
J.-B. Leriche ◽  
...  

Author(s):  
Ogün Baris Tapar ◽  
Jérémy Epp ◽  
Matthias Steinbacher ◽  
Jens Gibmeier

AbstractAn experimental heat treatment chamber and control system were developed to perform in-situ X-ray diffraction experiments during low-pressure carburizing (LPC) processes. Results from the experimental chamber and industrial furnace were compared, and it was proven that the built system is reliable for LPC experiments. In-situ X-ray diffraction investigations during LPC treatment were conducted at the German Electron Synchrotron Facility in Hamburg Germany. During the boost steps, carbon accumulation and carbide formation was observed at the surface. These accumulation and carbide formation decelerated the further carbon diffusion from atmosphere to the sample. In the early minutes of the diffusion steps, it is observed that cementite content continue to increase although there is no presence of gas. This effect is attributed to the high carbon accumulation at the surface during boost steps which acts as a carbon supply. During quenching, martensite at higher temperature had a lower c/a ratio than later formed ones. This difference is credited to the early transformation of austenite regions having lower carbon content. Also, it was noticed that the final carbon content dissolved in martensite reduced compared to carbon in austenite before quenching. This reduction was attributed to the auto-tempering effect.


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