scholarly journals THE MEASUREMENT OF THE INTEGRATED INTENSITY BY MEANS OF A SINGLE CRYSTAL X-RAY DIFFRACTOMETER

1958 ◽  
Vol 2 (5) ◽  
pp. 283-297
Author(s):  
YOICHI IITAKA
Keyword(s):  
Single Crystal ◽  
X Ray ◽  
Integrated Intensity

scholarly journals Estimation of Single Crystal Integrated X-ray Intensity within a Designated (D?, D2?) Domain

1983 ◽  
Vol 36 (1) ◽  
pp. 79 ◽  
Author(s):  
A McL Mathieson
Keyword(s):  
Single Crystal ◽  
Scintillation Detector ◽  
Truncation Error ◽  
Bragg Reflection ◽  
Major Error ◽  
Error Source ◽  
X Ray ◽  
D2 Domain ◽  
Integrated Intensity ◽  
Small Single Crystal

It is shown that measurement of the integrated intensity of a Bragg X-ray reflection within a precisely defined area of the (Aw, A2() distribution (Mathieson 1982a) is possible using a standard scintillation detector. The method involves an aperture system in front of the detector, consisting of two halves which are independently controlled so that both the width and position of the aperture are variable and can follow the A2() boundaries of the sections of any specified convex domain in (Aw, A2() space, as the specimen crystal steps in Aw. By taking account of the dispersion of the wavelength, crystal mosaicity and source components, the method can (a) exclude those extraneous contributions which, particularly at low () angles, constitute a major error source with conventional fixed-aperture procedures and (b) obviate the so-called truncation error at high () angles. This boundary-following method therefore provides, by a simple instrumental operation, a much closer estimate of the true integrated intensity of a Bragg reflection from a small single crystal than is feasible with the use of a fixed aperture. Once the main parameters of the experiment are determined, the procedure requires no greater expenditure of time than the traditional fixed-aperture method.

Electron Microscopy of Shock Loaded Polycrystalline Beryllium

1974 ◽  
Vol 32 ◽  
pp. 506-507 ◽  
Author(s):  
J. M. Galbraith ◽  
L. E. Murr ◽  
A. L. Stevens
Keyword(s):  
Electron Microscopy ◽  
Wave Propagation ◽  
Structural Change ◽  
Single Crystal ◽  
Diffraction Pattern ◽  
Shock Loading ◽  
Slip Systems ◽  
Compression Tests ◽  
X Ray Diffraction ◽  
X Ray

Uniaxial compression tests and hydrostatic tests at pressures up to 27 kbars have been performed to determine operating slip systems in single crystal and polycrystal1ine beryllium. A recent study has been made of wave propagation in single crystal beryllium by shock loading to selectively activate various slip systems, and this has been followed by a study of wave propagation and spallation in textured, polycrystal1ine beryllium. An alteration in the X-ray diffraction pattern has been noted after shock loading, but this alteration has not yet been correlated with any structural change occurring during shock loading of polycrystal1ine beryllium.This study is being conducted in an effort to characterize the effects of shock loading on textured, polycrystal1ine beryllium. Samples were fabricated from a billet of Kawecki-Berylco hot pressed HP-10 beryllium.

Automatic measurement of SAED patterns from asbestos minerals

1988 ◽  
Vol 46 ◽  
pp. 846-847
Author(s):  
J. C. Russ ◽  
T. Taguchi ◽  
P. M. Peters ◽  
E. Chatfield ◽  
J. C. Russ ◽  
...  
Keyword(s):  
Diffraction Pattern ◽  
High Precision ◽  
Diffraction Data ◽  
Automatic Measurement ◽  
Automatic Method ◽  
Important Method ◽  
X Ray ◽  
Integrated Intensity ◽  
Asbestiform Minerals ◽  
True Center

Conventional SAD patterns as obtained in the TEM present difficulties for identification of materials such as asbestiform minerals, although diffraction data is considered to be an important method for making this purpose. The preferred orientation of the fibers and the spotty patterns that are obtained do not readily lend themselves to measurement of the integrated intensity values for each d-spacing, and even the d-spacings may be hard to determine precisely because the true center location for the broken rings requires estimation. We have implemented an automatic method for diffraction pattern measurement to overcome these problems. It automatically locates the center of patterns with high precision, measures the radius of each ring of spots in the pattern, and integrates the density of spots in that ring. The resulting spectrum of intensity vs. radius is then used just as a conventional X-ray diffractometer scan would be, to locate peaks and produce a list of d,I values suitable for search/match comparison to known or expected phases.

Crystal structure of an inclusion complex between chiral monoaza-15-crown-5 and S(–)-1-phenyl-ethyl ammonium percholorate

2003 ◽  
Vol 218 (5) ◽  
Author(s):  
Süheyla Özbey ◽  
F. B. Kaynak ◽  
M. Toğrul ◽  
N. Demirel ◽  
H. Hoşgören
Keyword(s):  
Crystal Structure ◽  
Inclusion Complex ◽  
Single Crystal ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
New Type

AbstractA new type of inclusion complex, S(–)-1 phenyl ethyl ammonium percholorate complex of R-(–)-2-ethyl - N - benzyl - 4, 7, 10, 13 - tetraoxa -1- azacyclopentadecane, has been prepared and studied by NMR, IR and single crystal X-ray diffraction techniques. The compound crystallizes in space group

Single Crystal Growth of High-Pressure Phases of Ice and Salt Hydrate Far Below the Original Melting Point by Mixing Alcohol: Crystal Structure Determination of Magnesium Chloride Heptahydrate

2020 ◽  
Author(s):  
Keishiro Yamashita ◽  
Kazuki Komatsu ◽  
Hiroyuki Kagi
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Crystal Growth ◽  
Single Crystal ◽  
Room Temperature ◽  
Growth Technique ◽  
Salt Hydrate ◽  
X Ray

An crystal-growth technique for single crystal x-ray structure analysis of high-pressure forms of hydrogen-bonded crystals is proposed. We used alcohol mixture (methanol: ethanol = 4:1 in volumetric ratio), which is a widely used pressure transmitting medium, inhibiting the nucleation and growth of unwanted crystals. In this paper, two kinds of single crystals which have not been obtained using a conventional experimental technique were obtained using this technique: ice VI at 1.99 GPa and MgCl<sub>2</sub>·7H<sub>2</sub>O at 2.50 GPa at room temperature. Here we first report the crystal structure of MgCl2·7H2O. This technique simultaneously meets the requirement of hydrostaticity for high-pressure experiments and has feasibility for further in-situ measurements.

Tris(pyrazolyl)borate Copper Hydroxide Complexes Featuring Tunable Intramolecular H-bonding

2019 ◽  
Author(s):  
Evan Gardner ◽  
Caitlyn Cobb ◽  
Jeffery A. Bertke ◽  
Timothy H. Warren
Keyword(s):  
Single Crystal ◽  
Copper Hydroxide ◽  
X Ray ◽  
Modular Synthesis ◽  
Pendant Arm ◽  
Copper Center ◽  
Vibrational Studies

A modular synthesis provides access to a series of new tris(pyrazolyl)borate ligands <sup>XpyMe</sup>TpK that possess a single functionalized pendant pyridyl (py) or pyrimidyl (pyd) arm designed to engage in tunable intramolecular H-bonding to metal–bound functionalities. To illustrate such H-bonding interactions, a series of [<sup>XpyMe</sup>TpCu]<sub>2</sub>(𝜇–OH)<sub>2</sub>(<b>6a</b><b>–6e</b>) complexes were synthesized from the corresponding <sup>XpyMe</sup>TpCu–OAc (<b>5a–5e</b>) complexes. Single crystal X-ray structures of three new dinuclear [<sup>XpyMe</sup>TpCu]<sub>2</sub>(𝜇–OH)<sub>2</sub>complexes reveal H-bonding between the pendant heterocycle and bridging hydroxide ligands while the donor arm engages the copper center in an unusual monomeric <sup>DMAPMe</sup>TpCu–OH complex. Vibrational studies (IR) of each bridging hydroxide complex reveal reduced 𝜈<sub>OH </sub>frequencies that tracks with the H-bond accepting ability of the pendant arm.

Tris(pyrazolyl)borate Copper Hydroxide Complexes Featuring Tunable Intramolecular H-bonding

2019 ◽  
Author(s):  
Evan Gardner ◽  
Caitlyn Cobb ◽  
Jeffery A. Bertke ◽  
Timothy H. Warren
Keyword(s):  
Single Crystal ◽  
Copper Hydroxide ◽  
X Ray ◽  
Modular Synthesis ◽  
Pendant Arm ◽  
Copper Center ◽  
Vibrational Studies

A modular synthesis provides access to a series of new tris(pyrazolyl)borate ligands <sup>XpyMe</sup>TpK that possess a single functionalized pendant pyridyl (py) or pyrimidyl (pyd) arm designed to engage in tunable intramolecular H-bonding to metal–bound functionalities. To illustrate such H-bonding interactions, a series of [<sup>XpyMe</sup>TpCu]<sub>2</sub>(𝜇–OH)<sub>2</sub>(<b>6a</b><b>–6e</b>) complexes were synthesized from the corresponding <sup>XpyMe</sup>TpCu–OAc (<b>5a–5e</b>) complexes. Single crystal X-ray structures of three new dinuclear [<sup>XpyMe</sup>TpCu]<sub>2</sub>(𝜇–OH)<sub>2</sub>complexes reveal H-bonding between the pendant heterocycle and bridging hydroxide ligands while the donor arm engages the copper center in an unusual monomeric <sup>DMAPMe</sup>TpCu–OH complex. Vibrational studies (IR) of each bridging hydroxide complex reveal reduced 𝜈<sub>OH </sub>frequencies that tracks with the H-bond accepting ability of the pendant arm.

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