scholarly journals An extended x-ray absorption fine structure study of rare-earth phosphate glasses near the metaphosphate composition

1999 ◽  
Vol 14 (12) ◽  
pp. 4706-4714 ◽  
Author(s):  
R. Anderson ◽  
T. Brennan ◽  
J. M. Cole ◽  
G. Mountjoy ◽  
D. M. Pickup ◽  
...  
Keyword(s):  
Fine Structure ◽  
Rare Earth ◽  
Variable Temperature ◽  
Structure Study ◽  
Phosphate Glasses ◽  
Rare Earth Ions ◽  
Glassy Matrix ◽  
X Ray ◽  
Absorption Fine ◽  
X Ray Absorption

A variable-temperature (79, 145, and 293 K) extended x-ray absorption fine structure study, using rare-earth LIII absorption edges, is reported for phosphate glasses doped with rare-earth elements (R, where R = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, and Er) with compositions close to metaphosphate, R(PO3)3. The results yield nearest-neighbor R–O distances that demonstrate the lanthanide contraction in a glassy matrix and an R–O coordination intermediate between 6 and 7 for rare-earth ions with smaller atomic number (Z) and 6 for rare-earth ions with largerZ. Thermal parameters show no significant changes in R–O distances or coordination numbers between 293 and 79 K. There is evidence of an R–P correlation between 3.3 and 3.6 Å and the beginning of a second R–O correlation at approximately 4 Å. No R–R correlations up to a distance of approximately 4 Å were observed.

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.

An extended x‐ray absorption fine structure study of aqueous rare earth perchlorate solutions in liquid and glassy states

1988 ◽  
Vol 89 (8) ◽  
pp. 5153-5159 ◽  
Author(s):  
Toshio Yamaguchi ◽  
Masaharu Nomura ◽  
Hisanobu Wakita ◽  
Hitoshi Ohtaki
Keyword(s):  
Fine Structure ◽  
Rare Earth ◽  
Structure Study ◽  
X Ray ◽  
Absorption Fine ◽  
X Ray Absorption

Local Static Distortion of Rare Earth Ions in ROs4Sb12 (R = La, Ce, Pr, Nd, Sm) by Extended X-ray Absorption Fine Structure

2008 ◽  
Vol 77 (6) ◽  
pp. 063601 ◽  
Author(s):  
Kiyofumi Nitta ◽  
Yusuke Omori ◽  
Daisuke Kikuchi ◽  
Takafumi Miyanaga ◽  
Katsuhiko Takegahara ◽  
...  
Keyword(s):  
Fine Structure ◽  
Rare Earth ◽  
Rare Earth Ions ◽  
X Ray ◽  
Absorption Fine ◽  
Static Distortion ◽  
X Ray Absorption

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 study of Ag particles isolated in solid argon

1984 ◽  
Vol 30 (2) ◽  
pp. 672-677 ◽  
Author(s):  
P. A. Montano ◽  
W. Schulze ◽  
B. Tesche ◽  
G. K. Shenoy ◽  
T. I. Morrison
Keyword(s):  
Fine Structure ◽  
Structure Study ◽  
X Ray ◽  
Absorption Fine ◽  
Ag Particles ◽  
Solid Argon ◽  
X Ray Absorption

X-ray absorption fine structure study of Cr 2 O 3-x

1995 ◽  
Author(s):  
I. Pop ◽  
O. Pop ◽  
Ioan Burda ◽  
C. Oprea ◽  
I. Nazarenco ◽  
...  
Keyword(s):  
Fine Structure ◽  
Structure Study ◽  
X Ray ◽  
Absorption Fine ◽  
X Ray Absorption
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