Structure of Cu Ions in (Cu + Halogen or Chalcogen)-Ion Implanted Silica Glasses

2003 ◽  
Vol 792 ◽  
Author(s):  
Kohei Fukumi ◽  
Akiyoshi Chayahara ◽  
Hiroyuki Kageyama ◽  
Naoyuki Kitamura ◽  
Kohei Kadono ◽  
...  
Keyword(s):  
Silica Glass ◽  
The Other ◽  
Homogeneous Distribution ◽  
Local Concentration ◽  
X Ray ◽  
Silica Glasses ◽  
X Ray Absorption ◽  
Glass Heat ◽  
Cu Ions ◽  
Ion Implanted

ABSTRACTStructure of Cu ions in (Cl+Cu)-, (Br+Cu)-, (I+Cu)-, (S+Cu)- and (Se+Cu)-ion implanted silica glasses has been studied by x-ray absorption and optical absorption spectroscopies. Cu ions formed Cu-O bonds in the as-implanted glasses, due to the homogeneous distribution of Cu ions and the low local concentration of halogen and chalcogen ions in silica glass. Heat treatment at about 600°C caused the formation of bonds between Cu ions and halogen/chalcogen ions without forming Cu halide or chalcogenide crystals. It was deduced that the formation of these bonds was controlled by the diffusion of Cu ions in silica glass. On the other hands, it was inferred that the formation of Cu halide and chalcogenide crystals was controlled not only by the diffusion of halogen/chalcogen ions but also by the diffusion of matrix ions.

Coordination structure of implanted manganese ions in silica glass

2000 ◽  
Vol 647 ◽  
Author(s):  
Kohei Fukumi ◽  
Akiyoshi Chayhara ◽  
Hiroyuki Kageyama ◽  
Kohei Kadono ◽  
Naoyuki Kitamura ◽  
...  
Keyword(s):  
Silica Glass ◽  
Room Temperature ◽  
Bond Distance ◽  
Coordination Structure ◽  
X Ray ◽  
Silica Glasses ◽  
Divalent State ◽  
Trivalent State ◽  
Oxide Crystals ◽  
X Ray Absorption

Abstract180 keV Mn+ ions were implanted in silica glass at doses ranging from 1×1016 to 2×1017 ions/cm2 at room temperature. The coordination structure of implanted Mn atoms was studied by X-ray absorption spectroscopy. It was found that Mn atoms were mainly coordinated by O atoms in silica glasses as-implanted at doses lower than 5×1016Mn+ions/cm2. The Mn-O bond distance was 2.07 Å and the coordination number was 4.3 in average. Mn atoms were mainly coordinated by Mn and O atoms in the glasses as-implanted at doses higher than 1×1017 Mn+ions/cm2. In all the glasses, Mn atoms which are coordinated by O atoms were present as divalent state. After heating at 700 °C in air, Mn atoms were present as trivalent state and tended to form oxide crystals.

Oxygen Reduction Effect on T’-Pr2-xCexCuO4 Nanopowders in the Underdoped Regime Studied by X-Ray Absorption near Edge Structure

2018 ◽  
Vol 936 ◽  
pp. 93-97 ◽  
Author(s):  
Irfanita Resky ◽  
Putu Eka Dharma Putra ◽  
Triono Bambang ◽  
Saiyasombat Chatree ◽  
Kamonsuangkasem Krongthong ◽  
...  
Keyword(s):  
Oxidation State ◽  
Oxidation States ◽  
Edge Structure ◽  
X Ray ◽  
Reduction Annealing ◽  
Gas Atmosphere ◽  
Reduction Effect ◽  
Ar Gas ◽  
X Ray Absorption ◽  
Cu Ions

This research is aimed to examine oxidation state of Copper (Cu) in both as-synthesized and reduced T’-Pr2-xCexCuO4 (T’-PCCO) with x = 0, 0.10, and 0.15 using Cu K-edge x-ray absorption near edge structure (XANES). The T‘-PCCO nanopowders were successfully synthesized by the chemically dissolved method with HNO3 as a dissolving agent continued by calcination at 1000°C for 15 h. The reduced T’-PCCO nanopowders were obtained by reduction annealing process at 700°C for 5 h under Ar gas atmosphere. The analyses of XANES spectra show that oxidation states of the Cu ions in all of the T'-PCCO nanopowders have values between +1 and +2. This indicates the existence of electron doping in the CuO2 planes, even in the undoped T’-structure. It is found that the oxidation states of the Cu ions change after reduction annealing depending on the existence of apical oxygen in the T'-structure. Based on the XANES analyses, it is revealed that the change of oxidation state is influenced by the presence of both electron and hole carriers in the two-carrier model of T’-structure.

Probing origin of room temperature ferromagnetism in Ni ion implanted ZnO films with x-ray absorption spectroscopy

2012 ◽  
Vol 111 (1) ◽  
pp. 013715 ◽  
Author(s):  
P. Srivastava ◽  
S. Ghosh ◽  
B. Joshi ◽  
P. Satyarthi ◽  
P. Kumar ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Zno Films ◽  
X Ray ◽  
X Ray Absorption ◽  
Ion Implanted

Conversion-electron extended X-ray absorption fine structure of ion-implanted nanocrystalline evaporated films

1990 ◽  
Vol 2 (41) ◽  
pp. 8113-8122 ◽  
Author(s):  
M Jaouen ◽  
P Bouillaud ◽  
T Girardeau ◽  
P Chartier ◽  
J Mimault ◽  
...  
Keyword(s):  
Fine Structure ◽  
Conversion Electron ◽  
X Ray ◽  
Absorption Fine ◽  
X Ray Absorption ◽  
Ion Implanted

X-Ray Absorption Study of Ti and Cr Reactions with Triazine and Polyimide

1993 ◽  
Vol 323 ◽  
Author(s):  
K. Konstadinidis ◽  
R. L. Opila ◽  
M. A. Marcus ◽  
K. Short ◽  
A. E. White ◽  
...  
Keyword(s):  
Fine Structure ◽  
Polymer Matrix ◽  
Model Compound ◽  
The Other ◽  
Absorption Study ◽  
X Ray ◽  
Buried Interfaces ◽  
Metal Atoms ◽  
Π Complex ◽  
X Ray Absorption

AbstractIn this paper we present results on the use of x-ray absorption spectroscopy and in particular extended x-ray absorption fine structure (EXAFS) to study non-destructively buried interfaces between polymers and metals. In particular we study the interaction between isolated metal atoms (Ti or Cr) and the surrounding polymer matrix (polyimide or triazine). The metal atoms have been introduced into the polymer matrix using ion-implantation. We find that Cr forms a π complex with the aromatic structures of polyimide and triazine in agreement with model compound and XPS data. Ti on the other hand seems to form Ti-O-C bonds with both polymers.

Local coordination geometry around Cu and Cu ions in silicate glasses: an X-ray absorption near edge structure investigation

2000 ◽  
Vol 14 (2) ◽  
pp. 211-216 ◽  
Author(s):  
C. Maurizio ◽  
F. d'Acapito ◽  
M. Benfatto ◽  
S. Mobilio ◽  
E. Cattaruzza ◽  
...  
Keyword(s):  
Silicate Glasses ◽  
Coordination Geometry ◽  
Structure Investigation ◽  
Edge Structure ◽  
X Ray ◽  
Local Coordination ◽  
X Ray Absorption ◽  
Cu Ions

XAFS Study of Iron and Nickel Speciation in Complex Sodium Aluminophosphate Based Glasses

MRS Advances ◽  
2016 ◽  
Vol 1 (63-64) ◽  
pp. 4209-4214
Author(s):  
S.V. Stefanovsky ◽  
V.Y. Murzin ◽  
M.B. Remizov ◽  
B.F. Myasoedov
Keyword(s):  
Glass Network ◽  
High Level Waste ◽  
Homogeneous Distribution ◽  
Mössbauer Study ◽  
X Ray ◽  
Steel Tanks ◽  
High Level ◽  
Octahedral Oxygen ◽  
X Ray Absorption ◽  
Good Agreement

ABSTRACTIron and nickel oxidation state and coordination in complex sodium aluminophosphate based glasses suggested as potential matrices for immobilization of legacy high level waste currently stored in stainless steel tanks at PA «Mayak» (Ural reg., Russia) were determined by X-ray absorption fine structure spectroscopy (XAFS: XANES/EXAFS). The glasses containing (wt.%) 20-30 Na2O, 6-12 Al2O3, 40-52 P2O5, 2-5 Fe2O3, 1-3 NiO, 0-6 B2O3, 10-15 other waste oxides produced by quenching of their melts were fully amorphous or contained minor Fe and Ni free phases. Fe in the glasses was found to be predominantly trivalent with an average Fe-O distance and a coordination number (CN) in the first shell of 1.94 to 1.97 Å and 5.2 to 5.8, respectively, mostly in octahedral oxygen environment. Ni is divalent in all the glasses and has in the first shell an average Ni-O distance and CN of 1.97 to 2.03 Å and 4.9 to 5.6, respectively. The first shell of both Fe and Ni is somewhat distorted. The second and further coordination shells are weakly appeared exhibiting no clustering and homogeneous distribution of Fe and Ni ions in the glass network. The data on Fe obtained are in good agreement with those from Mössbauer study of same glasses. After annealing glasses were partly devitrified and interpretation of XAFS data is strongly complicated due to Fe and Ni partitioning among crystalline and vitreous phases.

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