Effect of the ligand in the crystal structure of zinc oxide: an x-ray powder diffraction, x-ray absorption near-edge structure, and an extended x-ray absorption fine structure study

2016 ◽  
Vol 6 (2) ◽  
pp. 93-97
Author(s):  
María de los A. Cepeda-Pérez ◽  
Cristina M. Reyes-Marte ◽  
Valerie Ann Carrasquillo ◽  
William A. Muñiz ◽  
Edgar J. Trujillo ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Zinc Oxide ◽  
Fine Structure ◽  
Powder Diffraction ◽  
Structure Study ◽  
Edge Structure ◽  
X Ray ◽  
Absorption Fine ◽  
Image Position ◽  
X Ray Absorption

Abstract

Fluorescence Extended X-Ray Absorption Fine Structure Study on Local Structures of Rare-Earth-Doped InGaGdN

2016 ◽  
Vol 1133 ◽  
pp. 429-433
Author(s):  
Siti Nooraya Mohd Tawil ◽  
Shuichi Emura ◽  
Daivasigamani Krishnamurthy ◽  
Hajime Asahi
Keyword(s):  
Fine Structure ◽  
Rare Earth ◽  
Nearest Neighbor ◽  
Structure Study ◽  
Edge Structure ◽  
X Ray ◽  
Local Structures ◽  
Absorption Fine ◽  
X Ray Absorption

Local structures around gadolinium atoms in rare-earth (RE)-doped InGaGdN thin films were studied by means of fluorescence extended X-ray absorption fine structure (EXAFS) measured at the Gd LIII-edges. The samples were doped with Gd in-situ during growth by plasma-assisted molecular beam epitaxy (PAMBE). Gd LIII-edge EXAFS signal from the GaGdN, GdN and Gd foil were also measured as reference. The X-ray absorption near edge structure (XANES) spectra around Gd LIII absorption edge of InGaGdN samples observed at room temperature indicated the enhancement of intensities with the increase of Gd composition. Further EXAFS analysis inferred that the Gd atoms in InGaN were surrounded by similar atomic shells as in the case of GaGdN with the evidence indicating majority of Gd atoms substituted into Ga sites of InGaGdN. A slight elongation of bond length for the 2nd nearest-neighbor (Gd–Ga) of sample with higher Gd concentration was also observed.

Extended x-ray absorption fine structure study of incorporation of Bi and Pb atoms into the crystal structure of Ba4.5Nd9Ti18O54

1997 ◽  
Vol 12 (3) ◽  
pp. 799-804 ◽  
Author(s):  
M. Valant ◽  
I. Arčon ◽  
D. Suvorov ◽  
A. Kodre ◽  
T. Negas ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Fine Structure ◽  
Local Environment ◽  
Structure Study ◽  
X Ray ◽  
Absorption Fine ◽  
Exafs Study ◽  
X Ray Absorption

In the extended x-ray absorption fine structure (EXAFS) study of the local environment of Bi3+ and Pb2+ ions incorporated in Ba4.5Nd9Ti18O54, actual sites of Bi- and Pb-incorporation are determined. Evidence is given that dopant ions are not distributed randomly on all theoretically possible sites; Bi3+ selectively enters one out of three possible channels, corresponding to the sites x = 0.9484, y = 0.2500, z = 0.2939, and/or x = 0.0455, y = 0.2500, z = 0.6928 previously occupied by Nd3+, while Pb2+ selectively enters site x = 0.4940, y = 0.2500, and z = 0.4993 previously shared by Ba2+ and Nd3+.

Manganese K- and L3-Edge X-Ray Absorption Fine Structure Study of Zn1-xMnxTe

2013 ◽  
Vol 634-638 ◽  
pp. 2489-2492 ◽  
Author(s):  
Wei Zheng ◽  
Ling Yun Jang ◽  
Jenn Min Lee ◽  
Rui Sheng Zheng ◽  
Chee Wee Liu ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Fine Structure ◽  
Structure Study ◽  
Chemical Bonds ◽  
Bulk Materials ◽  
Absorption Data ◽  
Edge Structure ◽  
X Ray ◽  
Absorption Fine ◽  
X Ray Absorption

High-resolution synchrotron radiation x-ray absorption data on Mn K- and L3-edge for semimagnetic semiconductor Zn1-xMnxTe bulk materials are presented. A detailed analysis of the extended x-ray absorption fine structure by using the IFEFFIT program, and the chemical bonds of Mn-Te are obtained. The x-ray absorption near-edge structure of the Mn K- and L3-edges are investigated, and the electronic structure of Zn1-xMnxTe with various compositions are studied.

scholarly journals Study on crystallographic and electronic structure of micrometre-scale ZnO and ZnO:B rods via X-ray absorption fine-structure spectroscopy

2021 ◽  
Vol 28 (2) ◽  
pp. 448-454
Author(s):  
Selma Erat ◽  
Osman Murat Ozkendir ◽  
Saadet Yildirimcan ◽  
Selen Gunaydin ◽  
Messaoud Harfouche ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electronic Structure ◽  
Fine Structure ◽  
Crystallographic Analysis ◽  
Crystallographic Structure ◽  
Edge Structure ◽  
Exafs Data ◽  
X Ray ◽  
Absorption Fine ◽  
X Ray Absorption

X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine-structure (EXAFS) spectra were recorded to investigate the electronic structure and local crystal structure of ZnO and ZnO:B powders produced via hydrothermal synthesis. ZnO and ZnO:B grow as micrometre-scale rods with hexagonal shape, as confirmed by scanning electron microscopy micrographs. The number of broken ZnO:B rods increases with increasing B concentration, as observed in the images, due to B atoms locating in between the Zn and O atoms which weakens and/or breaks the Zn–O bonds. However, no disorder within the crystallographic structure of ZnO upon B doping is observed from X-ray diffraction results, which were supported by EXAFS results. To determine the atomic locations of boron atoms in the crystal structure and their influence on the zinc atoms, EXAFS data were fitted with calculated spectra using the crystal structure parameters obtained from the crystallographic analysis of the samples. EXAFS data fitting and complementary k-weight analysis revealed the positions of the B atoms – their positions were determined to be in between the Zn and O atoms.

scholarly journals An extended-X-ray-absorption-fine-structure study of freeze-dried and solution ovotransferrin. Evidence for water co-ordination at the metal-binding sites

1987 ◽  
Vol 247 (2) ◽  
pp. 369-375 ◽  
Author(s):  
S S Hasnain ◽  
R W Evans ◽  
R C Garratt ◽  
P F Lindley
Keyword(s):  
Fine Structure ◽  
Metal Binding ◽  
Binding Sites ◽  
Structure Study ◽  
Humid Atmosphere ◽  
Edge Structure ◽  
X Ray ◽  
Absorption Fine ◽  
Freeze Dried ◽  
X Ray Absorption

Our previous extended-X-ray-absorption-fine-structure (e.x.a.f.s.) study has shown that the probable iron environment in chicken ovotransferrin involves two low-Z ligands (consistent with phenolate linkages) at 0.185(1) nm and four low-Z ligands at 0.204(1) nm [Garratt, Evans, Hasnain & Lindley (1986) Biochem. J. 233, 479-484]. Herein we provide additional information from the e.x.a.f.s. and near-edge structure suggestive of a decrease in the co-ordination number of ovotransferrin-bound iron upon freeze-drying. These effects are reversible, and exposure of the freeze-dried material to a humid atmosphere results in reversion to the solution spectra. Progressive rehydration was monitored by using e.p.r. spectroscopy and was confirmed by recording the high-resolution X-ray-absorption near-edge structure (x.a.n.e.s.). The results suggest the presence of a labile water molecule at the iron-binding sites of ovotransferrin in solution.

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.

Extended X-ray absorption fine structure and multiple-scattering simulation of nickel dithiolene complexes Ni[S2C2(CF3)2]2n(n= −2, −1, 0) and an olefin adduct Ni[S2C2(CF3)2]2(1-hexene)

2015 ◽  
Vol 22 (1) ◽  
pp. 124-129 ◽  
Author(s):  
Weiwei Gu ◽  
Hongxin Wang ◽  
Kun Wang
Keyword(s):  
Fine Structure ◽  
Multiple Scattering ◽  
Edge Structure ◽  
X Ray ◽  
Absorption Fine ◽  
Square Planar ◽  
Square Planar Complexes ◽  
Uv Visible ◽  
Edge Features ◽  
X Ray Absorption

A series of Ni dithiolene complexes Ni[S2C2(CF3)]2n(n= −2, −1, 0) (1,2,3) and a 1-hexene adduct Ni[S2C2(CF3)2]2(C6H12) (4) have been examined by NiK-edge X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine-structure (EXAFS) spectroscopies. Ni XANES for1–3reveals clear pre-edge features and approximately +0.7 eV shift in the NiK-edge position for `one-electron' oxidation. EXAFS simulation shows that the Ni—S bond distances for1,2and3(2.11–2.16 Å) are within the typical values for square planar complexes and decrease by ∼0.022 Å for each `one-electron' oxidation. The changes in NiK-edge energy positions and Ni—S distances are consistent with the `non-innocent' character of the dithiolene ligand. The Ni—C interactions at ∼3.0 Å are analyzed and the multiple-scattering parameters are also determined, leading to a better simulation for the overall EXAFS spectra. The 1-hexene adduct4presents no pre-edge feature, and its NiK-edge position shifts by −0.8 eV in comparison with its starting dithiolene complex3. Consistently, EXAFS also showed that the Ni—S distances in4elongate by ∼0.046 Å in comparison with3. The evidence confirms that the neutral complex is `reduced' upon addition of olefin, presumably by olefin donating the π-electron density to the LUMO of3as suggested by UV/visible spectroscopy in the literature.

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