Calculated one-dimensional X-ray diffraction patterns of illite/smectite as fundamental particle aggregates

1988 ◽  
Author(s):  
Kathleen E. Tellier
Keyword(s):  
X Ray Diffraction ◽  
Fundamental Particle ◽  
One Dimensional ◽  
X Ray ◽  
Particle Aggregates ◽  
Diffraction Patterns

Analysis of Selected Area Diffraction Patterns With Winjade

1998 ◽  
Vol 4 (S2) ◽  
pp. 342-343 ◽  
Author(s):  
S. D. Walck ◽  
P. Ruzakowski-Athey
Keyword(s):  
Single Phase ◽  
Xrd Analysis ◽  
Analysis Program ◽  
X Ray Diffraction ◽  
Program Module ◽  
Vast Number ◽  
One Dimensional ◽  
X Ray ◽  
Diffraction Patterns ◽  
Xrd Patterns

The analysis of Selected Area Diffraction (SAD) patterns that are collected from a single phase material having sufficient crystallites to provide continuous rings is relatively straightforward. However, when this condition is not met and there may be several phases present having rings of a spotty nature, the pattern is complex and can be quite difficult to analyze manually because of the vast number of discrete spots. WinJade from MDI is an X-ray diffraction (XRD) analysis program with an Electron Diffraction Program Module (EDPM) that can be used to aid in the analysis of SAD patterns. The EDPM produces Integrated Circular Density Plots (ICDP), which are one-dimensional intensity profiles plotted as a function of equivalent XRD 20 values or crystal d-spacings. These ICDP's can be overlayed with XRD patterns or with reference lines from the NIST and JCPDS crystalline databases for direct comparisons.

Systematic studies on side-chain structures of phthalocyaninato-polysiloxanes: Polymerization and self-assembling behaviors

2015 ◽  
Vol 19 (01-03) ◽  
pp. 160-170 ◽  
Author(s):  
Satoru Yoneda ◽  
Tsuneaki Sakurai ◽  
Toru Nakayama ◽  
Kenichi Kato ◽  
Masaki Takata ◽  
...  
Keyword(s):  
Hexagonal Lattice ◽  
Side Chain ◽  
Electron Systems ◽  
X Ray Diffraction ◽  
Strong Electron ◽  
Covalent Bonds ◽  
One Dimensional ◽  
X Ray ◽  
Self Assembling ◽  
Diffraction Patterns

A series of dihydroxysilicon phthalocyanines having soluble side chains were synthesized and their bulk-state polymerization capability was investigated. Detailed spectroscopic study of the obtained phthalocyaninato-polysiloxanes revealed that strong electron donating ability and small steric hindrance of the peripheral substituents are the dominant factors to afford high-molecular weight polymers. The polymers show the behaviors of columnar liquid crystal (LC), which is clarified by the presence of clear X-ray diffraction patterns with a hexagonal lattice and birefringent textures in polarized optical microscopy. Because of the siloxane covalent bonds through central silicon atoms, phthalocyaninato-polysiloxanes accommodate one-dimensional phthalocyanine arrays with strong π-electronic couplings, thus exhibiting colmnar LC property even for the derivatives carrying short peripheral chains and leading to the relatively higher density of π-electron systems in the materials. This tendency is different from typical discotic small molecules that require optimum side chain structures for LC formation.

X-Ray Diffraction and Transmission Electron Microscopy Study of One-Dimensional Disorder Polytypes in SiC

1982 ◽  
Vol 40 ◽  
pp. 542-543
Author(s):  
M. Dubey ◽  
S. R. Singh ◽  
G. Singh
Keyword(s):  
Reciprocal Lattice ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
X Ray Diffraction ◽  
Lattice Imaging ◽  
One Dimensional ◽  
X Ray ◽  
Structural Modifications ◽  
Transmission Electron ◽  
Diffraction Patterns

Silicon carbide crystallizes into several structural modifications whose c-periodicities vary from 1 nm to more than 100 nm. Its high period structures are found to consist of intergrowth of smaller period structures at the unit cell level. The X-ray diffraction studies show that SiC crystals often possess one-dimensional disorder which is characterized by continuous streaks in X-ray diffraction patterns along ho.1 reciprocal lattice rows. However, it is shown that these streaks can also arise as a result of extremely high c-periodicities of the crystals as their ho.1 spots cannot be resolved easily. This contribution reports the observation of only few representative cases of so-called one-dimensional disordered crystals as observed in their X-ray and electron diffractions with lattice imaging.

X-ray diffraction of helices with arbitrary periodic ligand binding

1999 ◽  
Vol 55 (12) ◽  
pp. 2022-2027 ◽  
Author(s):  
Jin Gu ◽  
Leepo C. Yu
Keyword(s):  
Ligand Binding ◽  
Fourier Transforms ◽  
Muscle Actin ◽  
X Ray Diffraction ◽  
Helical Structures ◽  
One Dimensional ◽  
X Ray ◽  
Classical Formalism ◽  
Diffraction Patterns ◽  
The One

The classical formalism for studying diffraction from helical structures extended to include ligand binding is presented. The diffraction from such a binding pattern is the convolution of the Fourier transforms of the helix and the one-dimensional binding distribution. It is shown in the present analysis that it is not necessary to assume that the binding distribution is strictly periodic, as long as its Fourier transform can be determined. Analysis of the convolution gives a general expression for the diffracted intensities and the selection rule for the layer-lines. It shows two groups of layer-lines: one group is the familiar layer-line set from the original helix, while the other group shows reciprocal spacings shifted by 1/a from the original helix layer-lines, where a is the average repeat of the binding distribution. This group of layer-lines is contributed by the ligand only. By way of examples, calculated diffraction patterns from muscle actin filaments with bound myosin heads in three different binding patterns are presented. This approach provides a method for determining the ligand-binding distribution along helices by an analysis of their X-ray diffraction patterns.

scholarly journals X-ray diffraction patterns of one-dimensional quasicrystals

1993 ◽  
Vol 49 (s1) ◽  
pp. c336-c336
Author(s):  
H. Terauchi ◽  
M. Ishida ◽  
N. Sano ◽  
H. Kasatani ◽  
K. Sakaue
Keyword(s):  
X Ray Diffraction ◽  
One Dimensional ◽  
X Ray ◽  
Diffraction Patterns

X-ray diffraction study of a one-dimensional GaAs–AlAs superlattice

1977 ◽  
Vol 10 (1) ◽  
pp. 1-6 ◽  
Author(s):  
A. Segmüller ◽  
P. Krishna ◽  
L. Esaki
Keyword(s):  
Elastic Strain ◽  
Lattice Mismatch ◽  
Reciprocal Lattice ◽  
Unit Cell ◽  
Scattering Data ◽  
High Angle ◽  
X Ray Diffraction ◽  
One Dimensional ◽  
X Ray ◽  
Diffraction Patterns

Low- and high-angle X-ray diffraction patterns have been obtained from one-dimensional superlattice crystals prepared artificially by alternately depositing predetermined thicknesses of GaAs and AlAs, on the (001) face of a GaAs single-crystal by molecular-beam epitaxy. The positions and intensities of several superlattice reflections obtained along the 00l, 11l and 02l reciprocal lattice rows have been recorded. The structure of the superlattice can be approximated by a model which incorporates elastic strains in the unit cell due to the lattice mismatch between GaAs and AlAs. The number of Ga and Al layers in the superlattice unit cell can be accurately determined from the low-angle scattering data while the relative intensities of the high-angle superlattice reflections are a sensitive measure of the elastic strain present in the lattice. It is shown that the elastic strain agrees with the value computed theoretically on the assumption that the strain is not relieved by dislocations at the GaAs–AlAs interfaces.

Thermal evolution of Mg–Al and Ni–Al layered double hydroxides: the structure of the dehydrated phase

2016 ◽  
Vol 72 (6) ◽  
pp. 651-659 ◽  
Author(s):  
Svetlana Cherepanova ◽  
Natalya Leont'eva ◽  
Vladimir Drozdov ◽  
Vladimir Doronin
Keyword(s):  
Layered Double Hydroxides ◽  
Thermal Evolution ◽  
Water Molecules ◽  
Initial Structure ◽  
X Ray Diffraction ◽  
One Dimensional ◽  
X Ray ◽  
Turbostratic Disorder ◽  
Diffraction Patterns ◽  
Double Hydroxides

Simulation of X-ray diffraction patterns on the basis of the models of one-dimensional disordered crystals was used to investigate the structure of the dehydrated phase produced by dehydration of Mg–Al and Ni–Al layered double hydroxides at a temperature of ∼473–498 K. It was found that the removal of water molecules transforms the initial structure, which is a mixture of 3R1and 2H1polytypes, into a structure that comprises preferentially fragments of 3R2and 1Hpolytypes and has some turbostratic disorder.

β-NbBr5, eine neue Modifikation von Niobpentabromid mit einer eindimensionalen Lagenfehlordnung/ β-NbBr5, a New Modification of Niobium Pentabromide Having One-Dimensional Stacking Disorder

1983 ◽  
Vol 38 (5) ◽  
pp. 559-561 ◽  
Author(s):  
Ulrich Müller ◽  
Paul Klingelhöfer
Keyword(s):  
Close Packing ◽  
X Ray Diffraction ◽  
One Dimensional ◽  
X Ray ◽  
Lattice Constants ◽  
Closed Tube ◽  
Packing Arrangement ◽  
Diffraction Patterns ◽  
True Structure ◽  
Stacking Disorder

Abstract While trying to react NbBr5 with sulfur in a closed tube, crystals of the new modification β-NbBr5 were obtained. Its X-ray diffraction patterns have sharp reflexions and diffuse streaks showing the presence of a one-dimensional disorder. From the sharp reflexions alone, a statistically averaged sub-structure results; it has the space group Ccmm and the lattice constants a0 = 644, b0 = 1867 and c0 = 615 pm. Taking into account the diffuse streaks, the true structure was deduced; its lattice constants are a = 2a0, c = Co, b indefinite due to the disorder. β-NbBr5 is isostructural to tantalum pentaiodide. It consists of layers of (NbBr5)2 molecules that are stacked with displacement faults in the direction of b. The bromine atoms have a hexagonal close-packing arrangement.

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