EFFECTS OF MANY-BODY INTERACTIONS IN EXTENDED X-RAY ABSORPTION FINE STRUCTURE SPECTROSCOPY (EXAFS)

1987 ◽  
Vol 48 (C9) ◽  
pp. C9-1101-C9-1104 ◽  
Author(s):  
W. BARDYSZEWSKI ◽  
L. HEDIN
Keyword(s):  
Fine Structure ◽  
Many Body ◽  
X Ray ◽  
Absorption Fine ◽  
Many Body Interactions ◽  
X Ray Absorption

An extended X-ray absorption fine structure study of amorphous and crystalline germanium

1981 ◽  
Vol 59 (7) ◽  
pp. 876-882 ◽  
Author(s):  
E. D. Crozier ◽  
A. J. Seary
Keyword(s):  
Fine Structure ◽  
Random Network ◽  
Structural Disorder ◽  
Structure Study ◽  
Additional Contribution ◽  
Many Body ◽  
X Ray ◽  
Absorption Fine ◽  
Body Potential ◽  
X Ray Absorption

Extended X-ray absorption fine structure (EXAFS) results are presented for amorphous and crystalline Ge at temperatures ranging from 83 to 1085 K. Specific tests for the detection of asymmetry in the distribution of atoms are examined. In amorphous Ge the distribution of nearest neighbours is found to be Gaussian. In crystalline Ge at the highest temperatures studied a small asymmetry in the distribution of nearest atoms, attributed to anharmonicity in the effective two-body potential, must be included explicitly in the EXAFS analysis to determine changes in nearest neighbour distances to an accuracy of ± 0.01 Å. The temperature dependence of the disorder parameter σ12 in crystalline Ge is found to obey an Einstein model, contrary to earlier work. The structure of amorphous Ge is found to be consistent with a continuous random network of distorted tetrahedra in which the dynamic contribution to σ12(T) is given by the same force-constant law as in crystalline Ge. The static structural disorder provides an additional contribution to a σ12(T) which decreases as the crystalline temperature is approached. Many-body contributions to the reduction of the amplitude of the EXAFS interference function in amorphous and crystalline Ge are also determined empirically.

Many-body effects on extended x-ray absorption fine structure amplitudes

1980 ◽  
Vol 21 (12) ◽  
pp. 5521-5539 ◽  
Author(s):  
E. A. Stern ◽  
B. A. Bunker ◽  
S. M. Heald
Keyword(s):  
Fine Structure ◽  
Many Body ◽  
X Ray ◽  
Absorption Fine ◽  
Many Body Effects ◽  
X Ray Absorption

scholarly journals X-ray Absorption Fine Structure of bcc Crystals Studied Based on High-order Expanded Debye-Waller Factors

2017 ◽  
Vol 27 (1) ◽  
pp. 55
Author(s):  
Nguyen Van Hung ◽  
Trinh Thi Hue ◽  
Ha Dang Khoa ◽  
Tong Sy Tien
Keyword(s):  
Fine Structure ◽  
High Order ◽  
Atomic Interaction ◽  
Perturbation Approach ◽  
Single Pair ◽  
Many Body ◽  
X Ray ◽  
Absorption Fine ◽  
The Many ◽  
X Ray Absorption

In this work, X-ray absorption fine structure (XAFS) of bcc crystals and it Fourier transformmagnitude have been studied based on the anharmonic correlated Debye model high-order expandedDebye-Waller factors. The many-body effects are taken into account in the present one-dimensionalmodel based on the anharmonic effective potential that includes interactions of absorber andbackscatterer atoms with their first shell near neighbors, where Morse potential is assumed to describethe single-pair atomic interaction. Analytical expressions of four first temperature-dependent cumulantsof bcc crystals have been derived using the many-body perturbation approach. The obtained cumulantsare applied to calculating XAFS spectra and their Fourier transform magnitudes. Numerical results forFe are found to be in good agreement with experiment.

Structure of magnetic thin films and nanostructures studied by extended X-ray absorption fine structure

2000 ◽  
Vol 454-456 ◽  
pp. 723-728 ◽  
Author(s):  
H. Magnan ◽  
P. Le Fèvre ◽  
A. Midoir ◽  
D. Chandesris ◽  
H. Jaffrès ◽  
...  
Keyword(s):  
Thin Films ◽  
Fine Structure ◽  
Magnetic Thin Films ◽  
X Ray ◽  
Absorption Fine ◽  
X Ray Absorption

Kinetic analysis of Ag particle redispersion into ZSM-5 in the presence of coke using in situ XAFS

2021 ◽  
Author(s):  
Kazumasa Murata ◽  
Junya Ohyama ◽  
Atsushi Satsuma
Keyword(s):  
Fine Structure ◽  
Kinetic Analysis ◽  
X Ray ◽  
Xafs Spectroscopy ◽  
Absorption Fine ◽  
Ag Particles ◽  
In Situ Xafs ◽  
Ag Particle ◽  
X Ray Absorption

In the present study, the redispersion behavior of Ag particles on ZSM-5 in the presence of coke was observed using in situ X-ray absorption fine structure (XAFS) spectroscopy.

scholarly journals Backbonding contributions to small molecule chemisorption in a metal–organic framework with open copper(i) centers

2021 ◽  
Author(s):  
Gregory M. Su ◽  
Han Wang ◽  
Brandon R. Barnett ◽  
Jeffrey R. Long ◽  
David Prendergast ◽  
...  
Keyword(s):  
Fine Structure ◽  
Small Molecule ◽  
Metal Organic Framework ◽  
X Ray ◽  
Metal Site ◽  
Absorption Fine ◽  
Metal Organic ◽  
X Ray Absorption ◽  
Organic Framework

In situ near edge X-ray absorption fine structure spectroscopy directly probes unoccupied states associated with backbonding interactions between the open metal site in a metal–organic framework and various small molecule guests.

Structure study of the chalcogens and chalcogenides by X-ray absorption fine structure

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Hiroyuki Ikemoto ◽  
Takafumi Miyanaga
Keyword(s):  
Fine Structure ◽  
Covalent Bond ◽  
Narrow Channel ◽  
Structure Study ◽  
Chain Structure ◽  
Covalent Bonds ◽  
X Ray ◽  
Absorption Fine ◽  
Amorphous States ◽  
X Ray Absorption

AbstractIn this review, we make a survey of the structure studies for the chalcogen elements and several chalcogenides in liquid, amorphous and nanosized state by using X-ray absorption fine structure (XAFS). The chalcogen elements have hierarchic structures; the chain structure constructed with the strong covalent bond as a primary structure, and the weaker interaction between chains as a secondary one. Existence of these two kinds of interactions induces exotic behaviors in the liquid, amorphous and nanosized state of the chalcogen and chalcogenides. XAFS is a powerful structure analysis technique for multi-element systems and the disordered materials, so it is suitable for the study of such as liquid, amorphous and nanosized mixtures. In section 2, the structures for the liquid state are discussed, which show the interesting semiconductor-metal transition depending on their temperatures and components. In section 3, the structure for the amorphous states are discussed. Especially, some of chalcogens and chalcogenides present the photostructural change, which is important industrial application. In section 4, the structures of nanosized state, nanoparticles and isolated chain confined into the narrow channel, are discussed. The studies of the nanoparticle and the isolated chain reveal the alternative role between the intrachain covalent bonds and the interchain interaction.

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