X-Ray Absorption at Si K-Edge for Novel Compounds in the Ternary System Si-C-N

1996 ◽  
Vol 437 ◽  
Author(s):  
P. Kroll ◽  
A. Greiner ◽  
R. Riedel ◽  
S. Bender ◽  
R. Franke ◽  
...  
Keyword(s):  
Composite Material ◽  
Ternary System ◽  
Crystalline Phase ◽  
Room Temperature ◽  
X Ray ◽  
Solid Phases ◽  
X Ray Absorption

AbstractWe present results of Si K-edge XANES-investigations for novel Si-C-N containing solid phases prepared by annealing of Si(NCN)2 at temperatures between room temperature (RT) and 1600°C. The chemical equivalence of the NCN-group arid oxygen as a ligand of silicon is confirmed. The spectra show the presence of an intermediate crystalline phase and its decomposition. Furthermore the recrystallisation of a Si3N4/SiC composite material and its dependence on temperature can be seen.

scholarly journals Laboratory EXAFS determined structure of the stable complexes in the ternary Ni(ii)–EDTA–CN− system

2019 ◽  
Vol 21 (18) ◽  
pp. 9239-9245 ◽  
Author(s):  
Zoltán Németh ◽  
Éva G. Bajnóczi ◽  
Bogdán Csilla ◽  
György Vankó
Keyword(s):  
Ternary System ◽  
Aqueous Solutions ◽  
Absorption Spectroscopy ◽  
Cyanide Concentration ◽  
X Ray ◽  
System P ◽  
X Ray Absorption

Aqueous solutions of the ternary system Ni(ii)–EDTA–CN− are investigated with X-ray Absorption Spectroscopy (XAS) as a function of cyanide concentration with an enhanced laboratory von Hámos X-ray spectrometer.

scholarly journals Soft x-ray absorption spectroscopy of metalloproteins and high-valent metal-complexes at room temperature using free-electron lasers

2017 ◽  
Vol 4 (5) ◽  
pp. 054307 ◽  
Author(s):  
Markus Kubin ◽  
Jan Kern ◽  
Sheraz Gul ◽  
Thomas Kroll ◽  
Ruchira Chatterjee ◽  
...  
Keyword(s):  
Metal Complexes ◽  
Absorption Spectroscopy ◽  
Free Electron ◽  
Room Temperature ◽  
Free Electron Lasers ◽  
X Ray ◽  
High Valent ◽  
X Ray Absorption

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

Recovery of nanosize zinc from phosphor wastes with an ionic liquid

2009 ◽  
Vol 6 (3) ◽  
pp. 268 ◽  
Author(s):  
Hsin-Liang Huang ◽  
H. Paul Wang ◽  
Edward M. Eyring ◽  
Juu-En Chang
Keyword(s):  
Ionic Liquid ◽  
Absorption Spectroscopy ◽  
Room Temperature ◽  
Bond Distance ◽  
Extraction Process ◽  
Room Temperature Ionic Liquid ◽  
Zns Nanoparticles ◽  
Recovery Method ◽  
X Ray ◽  
X Ray Absorption

Environmental context. Very fine phosphor ashes are discharged from particulate collection systems (such as bag houses) in the cathode ray tube or television disassembling processes. Effective recovery of ZnO and ZnS nanoparticles from the phosphor ash can be achieved by extraction with a room temperature ionic liquid. By synchrotron radiation X-ray absorption spectroscopy, the obtained molecular scale data turn out to be very useful in revealing speciation of zinc in the extraction process, which also facilitates the development of a simple nanoparticle recovery method. Abstract. An effective, simple method has been developed for the recovery of ZnO and ZnS nanoparticles from hazardous phosphor ash waste. Experimentally, zinc (77%) in the phosphor ash (that contains mainly zinc (91%)) can be recovered by extraction with a room temperature ionic liquid (RTIL) ([C4mim][PF6], 1-butyl-3-methylimidazolium hexafluorophosphate). Component fitted X-ray absorption near edge structure (XANES) spectra of zinc indicate that metallic zinc (Zn) (9%) in the phosphor ash can be dissolved to form a Zn2+–1-methylimidazole ([mim]) complex during extraction with the RTIL. ZnS and ZnO nanoparticles (60–61%) can also be extracted from the phosphor. Over the 298–523 K temperature range, desired ZnO/ZnS ratios (0.3–0.6) can be obtained since interconversion of ZnS to ZnO in the RTIL is temperature dependent. The Fourier transformed extended X-ray absorption fine structure (EXAFS) data also show that the nanosize ZnS extracted in the RTIL possesses a Zn–S bond distance of 2.33 Å with coordination numbers (CNs) of 3.6–3.7. At 523 K, in the RTIL, ~30% of the ZnS is oxidised to form octahedral ZnO (with a bond distance of 2.10 Å and a CN of 6.1) that may coat the surfaces of the ZnS nanoparticles. This work exemplifies the utilisation of X-ray absorption spectroscopy (EXAFS and XANES) to reveal speciation and possible reaction pathways in a nanoparticle extraction process (with a RTIL) in detail.

scholarly journals Surface Chemistry Of Heterobimetallic Ge-M (M = Mo, W) Complexes In Zeolite Y

1991 ◽  
Vol 233 ◽  
Author(s):  
Aticha Borvornwattananont ◽  
Karin Moller ◽  
Thomas Bein
Keyword(s):  
Room Temperature ◽  
Zeolite Y ◽  
In Situ Ftir ◽  
Nay Zeolite ◽  
Zeolite Framework ◽  
Hy Zeolite ◽  
X Ray ◽  
Proton Form ◽  
X Ray Absorption

ABSTRACTThe intrazeolite chemistry of the two germylene complexes Cl2(THF)GeM(CO)5(M = Mo, W) was studied with x-ray absorption spectroscopy (Ge, Mo, W edge EXAFS) and in-situ FTIR/TPD-MS techniques. The slightly decarbonylated GeMo complex interacts with the framework of NaY zeolite at room temperature and retains the Ge-Mo bond up to about 100° C. In proton-loaded HY zeolite, framework interactions increase at elevated temperature, and the attached complex retains the Ge-Mo bond up to about 120° C. The Ge-Mo bond is cleaved at higher temperatures. MoC1x and Mo-Mo species are formed in NaY and HY zeolite, respectively, while GeClx fragments are anchored to the zeolite framework.The complex Cl2 (THF)GeW(CO) 5 retains all five CO ligands up to about 100° C in both NaY and the proton form. Detectable anchoring occurs at room temperature in NaY and at about 80° C in the proton form. WC1x species are formed upon cleavage of the Ge-W bond at higher temperatures.

scholarly journals The Determination of Interfacial Structure and Phase Transitions in Al/Cu and Al/Ni Interfaces by Means of Surface Extended X-Ray Absorption Fine Structure

1991 ◽  
Vol 238 ◽  
Author(s):  
E. V. Barrera ◽  
S. M. Heald
Keyword(s):  
Fine Structure ◽  
Room Temperature ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Interfacial Structure ◽  
Reaction Products ◽  
X Ray ◽  
Absorption Fine ◽  
Reaction Zones ◽  
X Ray Absorption

ABSTRACTSurface extended x-ray absorption fine structure (SEXAFS) was used to investigate the interfacial conditions of Al/Cu and Al/Ni shallow buried interfaces. Previous studies using glancing angle extended x-ray absorption fine structure, x-ray reflectivity, photoemission, and SEXAFS produced conflicting results as to whether or not the interfaces between Al and Cu and Al and Ni were reacted upon room temperature deposition. In this study polycrystalline bilayers of Al/Cu and Al/Ni and trilayers of Al/Cu/Al and Al/Ni/Al were deposited on tantalum foil at room temperature in ultra high vacuum and analyzed to evaluate the reactivity of these systems on a nanometer scale. It became overwhelming apparent that the interfacial phase reactions were a function of the vacuum conditions. Samples deposited with the optimum vacuum conditions showed reaction products upon deposition at room temperature which were characterized by comparisons to standards and by least squares fitting to be CuAl2 and NiAl3 respectively. The results of this study showed that the reacted zone thicknesses were readily dependent on the deposition parameters. For both Al on Cu and Al on Ni as well as the metal on Al conditions 10A reaction zones were observed. These reaction zones were smaller than that observed for bilayers of Al on Cu (30Å) and Al on Ni (60Å) where deposition rates were much higher and samples were much thicker. The reaction species are evident by SEXAFS, where the previous photoemission studies only indicated that changes had occurred. Improved vacuum conditions as compared to the earlier experiments is primarily the reason reactions on deposition were seen in this study as compared to the earlier SEXAFS studies.

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