Local Structure of Rare-earth Ions in Alkali Silicate Glasses Studied by Extended X-Ray Absorption Fine Structure

1999 ◽  
Vol 38 (S1) ◽  
pp. 168 ◽  
Author(s):  
Hirotaka Yamaguchi ◽  
Hiromichi Takebe
Keyword(s):  
Fine Structure ◽  
Rare Earth ◽  
Local Structure ◽  
Rare Earth Ions ◽  
Silicate Glasses ◽  
X Ray ◽  
Absorption Fine ◽  
Alkali Silicate ◽  
X Ray Absorption

Extended X-ray Absorption Fine Structure Studies of GaN Epilayers Doped in situ with Er and Eu During Molecular Beam Epitaxy

2003 ◽  
Vol 798 ◽  
Author(s):  
V. Katchkanov ◽  
J. F. W. Mosselmans ◽  
S. Dalmasso ◽  
K. P. O'Donnell ◽  
R. W. Martin ◽  
...  
Keyword(s):  
Fine Structure ◽  
Rare Earth ◽  
Molecular Beam Epitaxy ◽  
Local Structure ◽  
Molecular Beam ◽  
X Ray ◽  
Absorption Fine ◽  
X Ray Absorption ◽  
The Eu

ABSTRACTThe local structure around Er and Eu atoms introduced into GaN epilayers was studied by means of Extended X-ray Absorption Fine Structure above the appropriate rare-earth X-ray absorption edge. The samples were doped in situ during growth by Molecular Beam Epitaxy. The formation of ErN clusters was found in samples with high average Er concentrations of 32±6% and 12.4±0.8%, estimated by Wavelength Dispersive X-ray analysis. When the average Er concentration is decreased to 6.0±0.2%, 1.6±0.2% and 0.17±0.02%, Er is found in localised clusters of ErGaN phase with high local Er content. Similar behaviour is observed for Eu-doped samples. For an average Eu concentration of 30.5±0.5% clusters of pure EuN occur. Decreasing the Eu concentration to 10.4±0.5% leads to EuGaN clusters with high local Eu content. However, for a sample with an Eu concentration of 14.2±0.5% clustering of Eu was not observed.

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

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.

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.

scholarly journals Near edge x-ray absorption fine structure studies of local structure of dihexyldisulfide multilayer

2005 ◽  
Vol 54 (12) ◽  
pp. 5837
Author(s):  
Wu Tai-Quan ◽  
Tang Jing-Chang ◽  
Zhu Ping ◽  
Li Hai-Yang
Keyword(s):  
Fine Structure ◽  
Local Structure ◽  
X Ray ◽  
Absorption Fine ◽  
X Ray Absorption

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.

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