Oxygen-Induced Reversible Structural Change of Supported fine Silver Particles Observed by In Situ Optical Absorption and X-ray Diffraction

1990 ◽  
Vol 195 ◽  
Author(s):  
Akihisa Yanase ◽  
Hiroshi Komiyama ◽  
Kazunobu Tanaka
Keyword(s):  
Optical Absorption ◽  
Surface Stress ◽  
Lattice Parameter ◽  
Silver Particles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ambient Gases ◽  
First Time ◽  
Shape Of Particles

ABSTRACTIn situ measurements of optical absorption and x-ray diffraction for small supported silver particles were performed under defined atmospheres at temperatures below 723 K. We found, for the first time, reversible changes both in optical absorption spectrum and lattice parameter of silver particles against the cyclic exchange of ambient gases between 5% H2/He and 1% 02/He. The present data indicate that the adsorption of oxygen results in a reduction in surface stress of silver particles, leading to a change in the shape of particles.

In-situ High Temperature X-ray Diffraction Study of the Am-O System

MRS Advances ◽  
2016 ◽  
Vol 1 (62) ◽  
pp. 4133-4137 ◽  
Author(s):  
E. Epifano ◽  
R. C. Belin ◽  
J-C Richaud ◽  
R. Vauchy ◽  
M. Strach ◽  
...  
Keyword(s):  
High Temperature ◽  
Lattice Parameter ◽  
Minor Actinide ◽  
Controlled Atmosphere ◽  
X Ray Diffraction ◽  
X Ray ◽  
Binary Phase Diagrams ◽  
First Time ◽  
O Phase

ABSTRACTIn the frame of minor actinide recycling, (U,Am)O2 are promising transmutation targets. To assess the thermodynamic properties of the U-Am-O system, it is essential to have a thorough knowledge of the binary phase diagrams, which is difficult due to the lack of thermodynamic data on the Am-O system. Nevertheless, an Am-O phase diagram modelling has been recently proposed by Gotcu. Here, we show a recent investigation of the Am-O system using in-situ High Temperature X-ray Diffraction under controlled atmosphere. By coupling our experimental results with the thermodynamic calculations based on the Gotcu model, we propose for the first time a relation between the lattice parameter and the departure from stoichiometry.

Inflexible stoichiometry in bulk pyrite FeS2 as viewed by in situ and high-resolution X-ray diffraction

2018 ◽  
Vol 74 (5) ◽  
pp. 436-444 ◽  
Author(s):  
Rebecca D. McAuliffe ◽  
Daniel P. Shoemaker
Keyword(s):  
Gas Flow ◽  
Lattice Parameter ◽  
Iron Pyrite ◽  
X Ray Diffraction ◽  
Intrinsic Defects ◽  
X Ray ◽  
Solubility Range ◽  
Absorber Material ◽  
Line Compound

Non-stoichiometry is considered to be one of the main problems limiting iron pyrite, FeS2, as a photovoltaic absorber material. Although some historical diffraction experiments have implied a large solubility range of FeS2−δ with δ up to 0.25, the current consensus based on calculated formation energies of intrinsic defects has lent support to line-compound behavior. Here it is shown that pyrite stoichiometry is relatively inflexible in both reductive conditions and in autogenous sulfur partial pressure, which produces samples with precise stoichiometry of FeS2 even at different Fe/S ratios. By properly standardizing in situ gas-flow X-ray diffraction measurements, no significant changes in the lattice parameter of FeS2 can be resolved, which portrays iron pyrite as prone to forming sulfur-deficient compounds, but not intrinsic defects in the manner of NiS2−δ.

Probing atomic positions of adsorbed ammonia molecules in zeolite

2016 ◽  
Vol 52 (16) ◽  
pp. 3422-3425 ◽  
Author(s):  
Lin Ye ◽  
Benedict T.W. Lo ◽  
Jin Qu ◽  
Ian Wilkinson ◽  
Tim Hughes ◽  
...  
Keyword(s):  
X Ray Diffraction ◽  
Guest Molecules ◽  
X Ray ◽  
Adsorbed Ammonia ◽  
Experimental Errors ◽  
Zeolite P ◽  
First Time ◽  
Microporous Solids

The atomic positions and interactions between adsorbed guest molecules, such as ammonia in H-ZSM-5 microporous solids, are for the first time revealed by using in situ synchrotron powder X-ray diffraction combined with refinement within experimental errors.

A dispenser–reactor apparatus applied forin situXAS monitoring of Pt nanoparticle formation

2015 ◽  
Vol 22 (3) ◽  
pp. 736-744 ◽  
Author(s):  
Jocenir Boita ◽  
Marcus Vinicius Castegnaro ◽  
Maria do Carmo Martins Alves ◽  
Jonder Morais
Keyword(s):  
Photoelectron Spectroscopy ◽  
Metallic Nanoparticles ◽  
Pt Nanoparticles ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Two Stages ◽  
X Ray Absorption

In situtime-resolved X-ray absorption spectroscopy (XAS) measurements collected at the PtL3-edge during the synthesis of Pt nanoparticles (NPs) in aqueous solution are reported. A specially designed dispenser–reactor apparatus allowed for monitoring changes in the XAS spectra from the earliest moments of Pt ions in solution until the formation of metallic nanoparticles with a mean diameter of 4.9 ± 1.1 nm. By monitoring the changes in the local chemical environment of the Pt atoms in real time, it was possible to observe that the NPs formation kinetics involved two stages: a reduction-nucleation burst followed by a slow growth and stabilization of NPs. Subsequently, the synthesized Pt NPs were supported on activated carbon and characterized by synchrotron-radiation-excited X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and extended X-ray absorption fine structure (EXAFS). The supported Pt NPs remained in the metallic chemical state and with a reduced size, presenting slight lattice parameter contraction in comparison with the bulk Pt values.

Structural Behaviour of Solid Solution in the SmAlO3−TbAlO3 System

2015 ◽  
Vol 230 ◽  
pp. 39-44 ◽  
Author(s):  
Natalja Ohon ◽  
Leonid Vasylechko ◽  
Yurii Prots ◽  
Marcus Schmidt ◽  
I.I. Syvorotka
Keyword(s):  
Thermal Analysis ◽  
Solid Solution ◽  
Continuous Solid Solution ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
Structural Behaviour ◽  
X Ray ◽  
Synchrotron Powder Diffraction ◽  
Orthorhombic Perovskite

Phase and structural behaviour in the SmAlO3–TbAlO3system has been studied in a whole concentration range by means of laboratory X-ray diffraction,in situhigh temperature synchrotron powder diffraction and differential thermal analysis. Formation of the continuous solid solution Sm1−xTbxAlO3with the orthorhombic perovskite structure (space groupPbnm) has been established. Peculiarity of the investigated system is lattice parameter crossovers resulted in the existence of three regions with different relations of the lattice parameters. Based on the results obtained, as well as an available literature data for the “pure” SmAlO3and TbAlO3, a phase diagram of the pseudo-binary SmAlO3–TbAlO3system has been constructed.

scholarly journals Determination of Residual Stresses in an Oxidized Metallic Alloy under Thermal Loadings

Metals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 913
Author(s):  
Zhimao Wang ◽  
Jean-Luc Grosseau-Poussard ◽  
Benoît Panicaud ◽  
Guillaume Geandier ◽  
Pierre-Olivier Renault ◽  
...  
Keyword(s):  
Residual Stresses ◽  
Correction Method ◽  
Lattice Parameter ◽  
European Synchrotron Radiation Facility ◽  
X Ray Diffraction ◽  
Synchrotron Diffraction ◽  
X Ray ◽  
Crystallographic Planes

In order to clarify the mechanical features of a metal under thermal cyclic loading for the system Ni30Cr-Cr2O3, a specific study has been carried out. In the present work, the residual stresses in both the metal and the oxide layer have been investigated. An adapted method is applied to process the experimental results that were obtained by using in-situ high temperature synchrotron diffraction at European Synchrotron Radiation Facility. The sin2ψ analysis provides information about the stress in metal and oxide. X-ray diffraction provides also the lattice parameter between crystallographic planes in the metal. To obtain correct stress values, a correction method is also proposed taking into account different discrepancies sources to ensure the equation of mechanical balance.

scholarly journals Structure Quality of LuFeO3 Epitaxial Layers Grown by Pulsed-Laser Deposition on Sapphire/Pt

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 61 ◽  
Author(s):  
Sondes Bauer ◽  
Adriana Rodrigues ◽  
Lukáš Horák ◽  
Xiaowei Jin ◽  
Reinhard Schneider ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Lattice Parameter ◽  
Laser Deposition ◽  
X Ray Diffraction ◽  
X Ray

Structural quality of LuFeO 3 epitaxial layers grown by pulsed-laser deposition on sapphire substrates with and without platinum Pt interlayers has been investigated by in situ high-resolution X-ray diffraction (reciprocal-space mapping). The parameters of the structure such as size and misorientation of mosaic blocks have been determined as functions of the thickness of LuFeO 3 during growth and for different thicknesses of platinum interlayers up to 40 nm. By means of fitting of the time-resolved X-ray reflectivity curves and by in situ X-ray diffraction measurement, we demonstrate that the LuFeO 3 growth rate as well as the out-of-plane lattice parameter are almost independent from Pt interlayer thickness, while the in-plane LuFeO 3 lattice parameter decreases. We reveal that, despite the different morphologies of the Pt interlayers with different thickness, LuFeO 3 was growing as a continuous mosaic layer and the misorientation of the mosaic blocks decreases with increasing Pt thickness. The X-ray diffraction results combined with ex situ scanning electron microscopy and high-resolution transmission electron microscopy demonstrate that the Pt interlayer significantly improves the structure of LuFeO 3 by reducing the misfit of the LuFeO 3 lattice with respect to the material underneath.

Synthesis, characterisation, and electrical properties of novel nanostructured conducting poly(aniline-co-m-chloroaniline) with incorporated silver particles

2015 ◽  
Vol 69 (7) ◽  
Author(s):  
Janakiraman Vivekanandan ◽  
Arunachalam Mahudeswaran ◽  
Xiao-Yan Tang ◽  
Sangamesh G. Kumbar ◽  
Pachanoor Subbaian Vijayanand
Keyword(s):  
Spectroscopic Methods ◽  
Silver Particles ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Monomer Composition ◽  
Crystalline Nature ◽  
Poly Aniline ◽  
Scanning Electron

AbstractNovel copolymers of poly(aniline-co-m-chloroaniline)-doped dodecylbenzenesulphonic acid (DBSA) with embedded silver nanoparticles were synthesised using the in situ chemical oxidative method. The structural properties of the copolymers were characterised using the UV-VIS and FTIR spectroscopic methods. The crystalline nature of the copolymer was demonstrated by way of the X-ray diffraction (XRD) pattern. Scanning electron microscopy (SEM) revealed the presence of particle agglomerates measuring 50 nm to 100 nm on the surface of the nanocomposites. The electrical conductivity of the copolymer was dependent on the monomer composition and was found to be in the range of 10

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