Three-dimensional structure of multicomponent (Na2O)0.35[(P2O5)1 −x(B2O3)x]0.65glasses by high-energy x-ray diffraction and constrained reverse Monte Carlo simulations

2011 ◽  
Vol 23 (3) ◽  
pp. 035403 ◽  
Author(s):  
Sébastien Le Roux ◽  
Steve Martin ◽  
Randi Christensen ◽  
Yang Ren ◽  
Valeri Petkov
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Three Dimensional ◽  
High Energy ◽  
Dimensional Structure ◽  
Reverse Monte Carlo ◽  
X Ray Diffraction ◽  
X Ray ◽  
Three Dimensional Structure

Structure of Zinc Phosphate Glasses of 75 and 80 mole% ZnO Content Studied by X-Ray Diffraction and Reverse Monte Carlo Simulations

2005 ◽  
Vol 60 (7) ◽  
pp. 517-526 ◽  
Author(s):  
Uwe Hoppe ◽  
Yanko Dimitriev ◽  
Pal Jóvári
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
High Energy ◽  
Phosphate Glasses ◽  
Strong Increase ◽  
Reverse Monte Carlo ◽  
X Ray Diffraction ◽  
X Ray ◽  
Coordination Numbers ◽  
Q Factors

X-Ray diffraction, using high-energy photons from a synchrotron, was used to extend the investigation of (ZnO)x(P2O5)1−x glasses to samples of ZnO content close to x = 0.8 which were obtained by roller-quenching. The isolated PO4 tetrahedra are surrounded by ZnOn polyhedra, where Zn−O coordination numbers of ∼ 4.5 are determined. The small increase of NZnO from ∼ 4 at metaphosphate composition (x = 0.5) to ∼ 4.5 is not sufficient to explain the strong increase of the packing density beyond the minimum at x = 0.5. The medium-range order was analyzed on the basis of partial SPP(Q) and SZnZn(Q) factors obtained from Reverse Monte Carlo simulations of glasses with 0 ≤ x ≤ 0.8. The positions of the first peaks in these factors, the number densities of P and Zn atoms and knowledge of definite P-P and Zn-Zn distances were used to check the applicability of simple models such as the dense packing of uniform P- and Zn-centered spherical environments for glasses with x=0.8 and 0.5, the packing of corrugated sheets for vitreous P2O5 and the packing of phosphate chains for Zn metaphosphate glass.

scholarly journals Structural analysis of WO3-TeO2 glasses by neutron, high energy X-ray diffraction, reverse Monte Carlo simulations and XANES

2018 ◽  
Vol 495 ◽  
pp. 27-34 ◽  
Author(s):  
Atul Khanna ◽  
Margit Fábián ◽  
Hirdesh ◽  
P.S.R. Krishna ◽  
Christopher J. Benmore ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Structural Analysis ◽  
Monte Carlo Simulations ◽  
High Energy ◽  
Reverse Monte Carlo ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals Structure of levitated Si-Ge melts studied by high-energy x-ray diffraction in combination with reverse Monte Carlo simulations

2021 ◽  
Author(s):  
Irina Pozdnyakova ◽  
Oleksandr Roik ◽  
James W E Drewitt ◽  
Alekei Bytchkov ◽  
Florian Kargl ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
High Energy ◽  
Reverse Monte Carlo ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals Application of differential resonant high-energy X-ray diffraction to three-dimensional structure studies of nanosized materials: A case study of Pt–Pd nanoalloy catalysts

2018 ◽  
Vol 74 (5) ◽  
pp. 553-566 ◽  
Author(s):  
Valeri Petkov ◽  
Sarvjit Shastri ◽  
Jong-Woo Kim ◽  
Shiyao Shan ◽  
Jin Luo ◽  
...  
Keyword(s):  
Density Functional ◽  
Rational Design ◽  
Three Dimensional ◽  
High Energy ◽  
Atomic Scale ◽  
Dimensional Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Three Dimensional Structure ◽  
Nanosized Materials

Atoms in many of the increasingly complex nanosized materials of interest to science and technology do not necessarily occupy the vertices of Bravais lattices. The atomic scale structure of such materials is difficult to determine by traditional X-ray diffraction and so their functional properties remain difficult to optimize by rational design. Here, the three-dimensional structure of Pt x Pd100−x nanoalloy particles is determined, where x = 0, 14, 36, 47, 64 and 100, by a non-traditional technique involving differential resonant high-energy X-ray diffraction experiments conducted at the K edge of Pt and Pd. The technique is coupled with three-dimensional modeling guided by the experimental total and element-specific atomic pair distribution functions. Furthermore, using DFT (density functional theory) calculation based on the positions of atoms in the obtained three-dimensional structure models, the catalytic performance of Pt–Pd particles is explained. Thus, differential resonant high-energy X-ray diffraction is shown to be an excellent tool for three-dimensional structure studies of nanosized materials. The experimental and modeling procedures are described in good detail, to facilitate their wider usage.

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