Polyamorphic Amorphous Silicon at High Pressure: Raman and Spatially Resolved X-ray Scattering and Molecular Dynamics Studies

2011 ◽  
Vol 115 (48) ◽  
pp. 14246-14255 ◽  
Author(s):  
Dominik Daisenberger ◽  
Thierry Deschamps ◽  
Bernard Champagnon ◽  
Mohamed Mezouar ◽  
Raúl Quesada Cabrera ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
High Pressure ◽  
Amorphous Silicon ◽  
X Ray ◽  
Spatially Resolved ◽  
X Ray Scattering ◽  
Ray Scattering

scholarly journals Direct tomography imaging for inelastic X-ray scattering experiments at high pressure

2017 ◽  
Vol 24 (1) ◽  
pp. 269-275 ◽  
Author(s):  
Ch. J. Sahle ◽  
A. D. Rosa ◽  
M. Rossi ◽  
V. Cerantola ◽  
G. Spiekermann ◽  
...  
Keyword(s):  
High Pressure ◽  
Machine Learning Algorithms ◽  
Raman Scattering Spectroscopy ◽  
X Ray ◽  
Spatially Resolved ◽  
X Ray Scattering ◽  
Sample Edge ◽  
Pressure Medium ◽  
Diamond Anvils ◽  
Ray Scattering

A method to separate the non-resonant inelastic X-ray scattering signal of a micro-metric sample contained inside a diamond anvil cell (DAC) from the signal originating from the high-pressure sample environment is described. Especially for high-pressure experiments, the parasitic signal originating from the diamond anvils, the gasket and/or the pressure medium can easily obscure the sample signal or even render the experiment impossible. Another severe complication for high-pressure non-resonant inelastic X-ray measurements, such as X-ray Raman scattering spectroscopy, can be the proximity of the desired sample edge energy to an absorption edge energy of elements constituting the DAC. It is shown that recording the scattered signal in a spatially resolved manner allows these problems to be overcome by separating the sample signal from the spurious scattering of the DAC without constraints on the solid angle of detection. Furthermore, simple machine learning algorithms facilitate finding the corresponding detector pixels that record the sample signal. The outlined experimental technique and data analysis approach are demonstrated by presenting spectra of the SiL2,3-edge and OK-edge of compressed α-quartz. The spectra are of unprecedented quality and both the OK-edge and the SiL2,3-edge clearly show the existence of a pressure-induced phase transition between 10 and 24 GPa.

Raman and X-Ray Scattering Studies of High-Pressure Phases of Urea

2005 ◽  
Vol 109 (16) ◽  
pp. 8206-8215 ◽  
Author(s):  
F. J. Lamelas ◽  
Z. A. Dreger ◽  
Y. M. Gupta
Keyword(s):  
High Pressure ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

Sound velocity measurements of hcp Fe-Si alloy at high pressure and high temperature by inelastic X-ray scattering

2018 ◽  
Vol 103 (1) ◽  
pp. 85-90 ◽  
Author(s):  
Takanori Sakairi ◽  
Tatsuya Sakamaki ◽  
Eiji Ohtani ◽  
Hiroshi Fukui ◽  
Seiji Kamada ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Sound Velocity ◽  
Velocity Measurements ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

Liquid Structure of 1-Ethyl-3-methylimidazolium Alkyl Sulfates by X-ray Scattering and Molecular Dynamics

2012 ◽  
Vol 116 (45) ◽  
pp. 13448-13458 ◽  
Author(s):  
Marina Macchiagodena ◽  
Fabio Ramondo ◽  
Alessandro Triolo ◽  
Lorenzo Gontrani ◽  
Ruggero Caminiti
Keyword(s):  
Molecular Dynamics ◽  
Liquid Structure ◽  
X Ray ◽  
X Ray Scattering ◽  
Alkyl Sulfates ◽  
Ray Scattering

Structural refinement by restrained molecular-dynamics algorithm with small-angle X-ray scattering constraints for a biomolecule

2004 ◽  
Vol 37 (1) ◽  
pp. 103-109 ◽  
Author(s):  
Masaki Kojima ◽  
Alexander A. Timchenko ◽  
Junichi Higo ◽  
Kazuki Ito ◽  
Hiroshi Kihara ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Molecular Dynamics ◽  
Small Angle ◽  
Protein Structures ◽  
Saxs Data ◽  
X Ray ◽  
X Ray Scattering ◽  
Saxs Curve ◽  
Restrained Molecular Dynamics ◽  
Ray Scattering

A new algorithm to refine protein structures in solution from small-angle X-ray scattering (SAXS) data was developed based on restrained molecular dynamics (MD). In the method, the sum of squared differences between calculated and observed SAXS intensities was used as a constraint energy function, and the calculation was started from given atomic coordinates, such as those of the crystal. In order to reduce the contribution of the hydration effect to the deviation from the experimental (objective) curve during the dynamics, and purely as an estimate of the efficiency of the algorithm, the calculation was first performed assuming the SAXS curve corresponding to the crystal structure as the objective curve. Next, the calculation was carried out with `real' experimental data, which yielded a structure that satisfied the experimental SAXS curve well. The SAXS data for ribonuclease T1, a single-chain globular protein, were used for the calculation, along with its crystal structure. The results showed that the present algorithm was very effective in the refinement and adjustment of the initial structure so that it could satisfy the objective SAXS data.

Performance of various models in structural characterization of n -butanol: Molecular dynamics and X-ray scattering studies

2017 ◽  
Vol 229 ◽  
pp. 346-357 ◽  
Author(s):  
Jure Cerar ◽  
Andrej Lajovic ◽  
Andrej Jamnik ◽  
Matija Tomšič
Keyword(s):  
Molecular Dynamics ◽  
Structural Characterization ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

scholarly journals Inelastic x-ray scattering by electronic excitations under high pressure

2010 ◽  
Vol 82 (1) ◽  
pp. 847-896 ◽  
Author(s):  
Jean-Pascal Rueff ◽  
Abhay Shukla
Keyword(s):  
High Pressure ◽  
Electronic Excitations ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

Liquid Structure of 1-Propanol by Molecular Dynamics Simulations and X-Ray Scattering

2004 ◽  
Vol 33 (6/7) ◽  
pp. 797-809 ◽  
Author(s):  
Isao Akiyama ◽  
Masaya Ogawa ◽  
Keiichi Takase ◽  
Toshiyuki Takamuku ◽  
Toshio Yamaguchi ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Liquid Structure ◽  
X Ray ◽  
X Ray Scattering ◽  
Dynamics Simulations ◽  
Ray Scattering
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