Determination of the Atomic Structure of Solid Catalysts by X-Ray Diffraction

1994 ◽  
pp. 417-444 ◽  
Author(s):  
G. Bergeret ◽  
P. Gallezot
Keyword(s):  
Atomic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solid Catalysts

Atomic Structure of Rare Earth Si-Al-O-N Glasses

1998 ◽  
Vol 53 (5) ◽  
pp. 259-264 ◽  
Author(s):  
H. Uhlig ◽  
M.-J. Hoffmann ◽  
S. Steeb
Keyword(s):  
Rare Earth ◽  
Neutron Diffraction ◽  
Atomic Structure ◽  
Pair Correlation ◽  
X Ray Diffraction ◽  
Ionic Radii ◽  
X Ray ◽  
Structure Factors ◽  
Total Structure

Abstract In this paper the results of X-ray diffraction experiments of Ln-Si-Al-O-N (Ln = La, Gd, Yb) glasses are presented. Total structure factors and pair correlation functions allow the determination of the first coordination sphere of Ln atoms. The bond lengths observed correspond to the ionic radii of the Ln-ions surrounded by oxygen and nitrogen atoms. The presence of non-bridging nitrogen is discussed together with results of neutron diffraction, NMR-experiments and XPS-studies of other authors.

Studying Structure of Metallic Superlattices by "Symmetric" and "Asymmetric" X-rAY Diffraction

1993 ◽  
Vol 308 ◽  
Author(s):  
G. Gladyszewski ◽  
Ph. Goudeau ◽  
K.F. Badawi ◽  
A. Naudon
Keyword(s):  
Atomic Structure ◽  
General Procedure ◽  
Structural Disorder ◽  
X Ray Diffraction ◽  
X Ray ◽  
Superlattice Structure ◽  
Complete Determination ◽  
Psi Method

ABSTRACT"Symmetric" and "asymmetric" x-ray diffraction measurements are proposed as a tool for quantitative and complete determination of the superlattice structure. A general procedure which takes into account the atomic structure of the sublayers as well as structural disorder are presented. The "asymmetric" geometry using the "sin2psi" method is particularly emphasized.

THE GROWTH AND ATOMIC STRUCTURE OF THALLIUM ON COPPER(001)

1997 ◽  
Vol 04 (06) ◽  
pp. 1191-1196
Author(s):  
C. L. NICKLIN ◽  
C. NORRIS ◽  
C. BINNS ◽  
N. JONES ◽  
J. ALVAREZ ◽  
...  
Keyword(s):  
Atomic Structure ◽  
Ultrathin Films ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
Temperature Growth ◽  
X Ray

We report a determination of the room temperature growth and atomic structure of ultrathin films of thallium on copper(001) using surface X-ray diffraction. The results show clearly that the growth is layerwise up to two monolayers and islanded thereafter. This is contrary to earlier reports which suggested that the islanding commenced at one monolayer. The first submonolayer structure to appear is a c(4×4) arrangement. Reflectivity scans suggest that there is significant reordering of the substrate at this coverage.

Sem and X-Ray Analysis of Renal and Biliary Calculi

1976 ◽  
Vol 34 ◽  
pp. 306-307
Author(s):  
R. J. Narconis ◽  
G. L. Johnson
Keyword(s):  
Chemical Constituents ◽  
Natural State ◽  
X Ray Diffraction ◽  
Chemical Methods ◽  
X Ray ◽  
Additional Dimension ◽  
Biliary Calculi ◽  
Calculus Formation ◽  
Scanning Electron

Analysis of the constituents of renal and biliary calculi may be of help in the management of patients with calculous disease. Several methods of analysis are available for identifying these constituents. Most common are chemical methods, optical crystallography, x-ray diffraction, and infrared spectroscopy. The application of a SEM with x-ray analysis capabilities should be considered as an additional alternative.A scanning electron microscope equipped with an x-ray “mapping” attachment offers an additional dimension in its ability to locate elemental constituents geographically, and thus, provide a clue in determination of possible metabolic etiology in calculus formation. The ability of this method to give an undisturbed view of adjacent layers of elements in their natural state is of advantage in determining the sequence of formation of subsequent layers of chemical constituents.

New Coordination Compounds of Fe(III) with Organic Ligands

2009 ◽  
Vol 59 (12) ◽  
Author(s):  
Mihaela Flondor ◽  
Ioan Rosca ◽  
Doina Sibiescu ◽  
Mihaela-Aurelia Vizitiu ◽  
Daniel-Mircea Sutiman ◽  
...  
Keyword(s):  
Chemical Analysis ◽  
Complex Compounds ◽  
Organic Ligands ◽  
X Ray Diffraction ◽  
X Ray ◽  
Elemental Chemical Analysis ◽  
Structural Formulae ◽  
Paramagnetic Properties

In this paper the synthesis and the study of some complex compounds of Fe(III) with ligands derived from: 2-(4-chloro-phenylsulfanyl)-1-(2-hydroxy-3,5-diiodo-phenyl)-ethanone (HL1), 1-(3,5-dibromo-2-hydroxy-phenyl)-2-phenylsulfanyl-ethanone(HL2), and 2-(4-chloro-phenylsulfanyl)-1-(3,5-dibromo-2-hydroxy-phenyl)-ethanone (HL3) is presented. The characterization of these complexes is based on method as: the elemental chemical analysis, IR and ESR spectroscopy, M�ssbauer, the thermogravimetric analysis and X-ray diffraction. Study of the IR and chemical analysis has evidenced that the precipitates form are a complexes and the combination ratio of M:L is 1:2. The central atoms of Fe(III) presented paramagnetic properties and a octaedric hybridization. Starting from this precipitation reactions, a method for the gravimetric determination of Fe(III) with this organic ligands has been possible. Based on the experimental data on literature indications, the structural formulae of the complex compounds are assigned.

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