X‐Ray Absorption Fine Structure Spectra and the Oxidation State of Nickel in Some of Its Oxycompounds

1994 ◽  
Vol 141 (6) ◽  
pp. L69-L71 ◽  
Author(s):  
A. N. Mansour ◽  
C. A. Melendres ◽  
M. Pankuch ◽  
R. A. Brizzolara
Keyword(s):  
Fine Structure ◽  
Oxidation State ◽  
X Ray ◽  
Absorption Fine ◽  
X Ray Absorption

ChemInform Abstract: X-Ray Absorption Fine Structure Spectra and the Oxidation State of Nickel in Some of Its Oxycompounds.

ChemInform ◽  
2010 ◽  
Vol 25 (41) ◽  
pp. no-no
Author(s):  
A. N. MANSOUR ◽  
C. A. MELENDRES ◽  
M. PANKUCH ◽  
R. A. BRIZZOLARA
Keyword(s):  
Fine Structure ◽  
Oxidation State ◽  
X Ray ◽  
Absorption Fine ◽  
X Ray Absorption

In situ X-ray absorption fine structure and optical reflectance studies of electrodeposited nickel hydrous oxide films in alkaline electrolytes

1997 ◽  
Vol 75 (11) ◽  
pp. 1721-1729 ◽  
Author(s):  
Yining Hu ◽  
In Tae Bae ◽  
Yibo Mo ◽  
Daniel A. Scherson ◽  
Mark R. Antonio
Keyword(s):  
Fine Structure ◽  
Oxidation State ◽  
Reflectance Spectroscopy ◽  
Hydrous Oxide ◽  
Optical Reflectance ◽  
X Ray ◽  
Absorption Fine ◽  
Alkaline Electrolytes ◽  
X Ray Absorption

X-ray absorption fine structure (XAFS) and optical reflectance spectroscopy (RS) have been used to examine in situ electronic and structural aspects of nickel hydrous oxide, α-Ni(OH)2(hyd), electrodes supported on gold in alkaline electrolytes as a function of their state of charge. The extended X-ray absorption fine structure (EXAFS) of α-Ni(OH)2(hyd) electrodes in the uncharged (UC, or discharged) and overcharged (OC, orfully charged) states yielded, in each case, a single set of two distinct nearest-neighbor shells, with distances, d(Ni—O)1 = 2.05 ± 0.02 Å and d(Ni—Ni)1 = 3.11 ± 0.02 Å for UC, and d(Ni—O)1 = 1.87 ± 0.02 Å and d(Ni—Ni)1 = 2.83 ± 0.02 Å for OC. The in situ EXAFS of films allowed to self-discharge following overcharge could be fit with contributions from both sets of shells, suggesting that only two types of nickel sites are sufficient to account for the redox chemistry of this material. These data, in addition to information derived both from quantitative X-ray absorption near-edge structure (XANES) and optical RS in the visible range, indicate that the excess anodic charge, i.e., beyond the one-electron oxidation of Ni2+ sites, observed during the first oxidation of freshly prepared α-Ni(OH)2(hyd) electrodes may not be related to oxidation state changes involving nickel sites in the lattice, and, therefore, do not support the existence of nickel sites with a formal oxidation state higher than three for charged or overcharged electrodes in this media. Keywords: nickel oxide, reflectance spectroscopy, EXAFS, in situ measurements.

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.

scholarly journals Local Structure and Dynamics of Functional Materials Studied by X-ray Absorption Fine Structure

Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1315
Author(s):  
Takafumi Miyanaga
Keyword(s):  
Fine Structure ◽  
Local Structure ◽  
Chemical Reactivity ◽  
Functional Materials ◽  
X Ray ◽  
Structure And Dynamics ◽  
Absorption Fine ◽  
Structure Phase Transition ◽  
Local Electronic Structure ◽  
X Ray Absorption

X-ray absorption fine structure (XAFS) is a powerful technique used to analyze a local electronic structure, local atomic structure, and structural dynamics. In this review, I present examples of XAFS that apply to the local structure and dynamics of functional materials: (1) structure phase transition in perovskite PbTiO3 and magnetic FeRhPd alloys; (2) nano-scaled fluctuations related to their magnetic properties in Ni–Mn alloys and Fe/Cr thin films; and (3) the Debye–Waller factors related to the chemical reactivity for catalysis in polyanions and ligand exchange reaction. This study shows that the local structure and dynamics are related to the characteristic function of the materials.

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