A New X‐Ray Diffraction Method for Studying Imperfections of Crystal Structure in Polycrystalline Specimens

1951 ◽  
Vol 22 (5) ◽  
pp. 665-672 ◽  
Author(s):  
Alfred J. Reis ◽  
Jerome J. Slade ◽  
Sigmund Weissmann
Keyword(s):  
Crystal Structure ◽  
Diffraction Method ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals Magnetically Oriented Powder Crystal to Indexing and Structure Determination

2014 ◽  
Vol 70 (a1) ◽  
pp. C1560-C1560
Author(s):  
Fumiko Kimura ◽  
Wataru Oshima ◽  
Hiroko Matsumoto ◽  
Hidehiro Uekusa ◽  
Kazuaki Aburaya ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Crystal Lattice ◽  
Powder Diffraction ◽  
Diffraction Method ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystal Lattice Parameters

In pharmaceutical sciences, the crystal structure is of primary importance because it influences drug efficacy. Due to difficulties of growing a large single crystal suitable for the single crystal X-ray diffraction analysis, powder diffraction method is widely used. In powder method, two-dimensional diffraction information is projected onto one dimension, which impairs the accuracy of the resulting crystal structure. To overcome this problem, we recently proposed a novel method of fabricating a magnetically oriented microcrystal array (MOMA), a composite in which microcrystals are aligned three-dimensionally in a polymer matrix. The X-ray diffraction of the MOMA is equivalent to that of the corresponding large single crystal, enabling the determination of the crystal lattice parameters and crystal structure of the embedded microcrytals.[1-3] Because we make use of the diamagnetic anisotropy of crystal, those crystals that exhibit small magnetic anisotropy do not take sufficient three-dimensional alignment. However, even for these crystals that only align uniaxially, the determination of the crystal lattice parameters can be easily made compared with the determination by powder diffraction pattern. Once these parameters are determined, crystal structure can be determined by X-ray powder diffraction method. In this paper, we demonstrate possibility of the MOMA method to assist the structure analysis through X-ray powder and single crystal diffraction methods. We applied the MOMA method to various microcrystalline powders including L-alanine, 1,3,5-triphenyl benzene, and cellobiose. The obtained MOMAs exhibited well-resolved diffraction spots, and we succeeded in determination of the crystal lattice parameters and crystal structure analysis.

The Influence of Emulsifiers on the Crystal Properties of Tristearin and Trilaurin

1988 ◽  
Vol 3 (1) ◽  
pp. 19-22 ◽  
Author(s):  
J. Schlichter ◽  
I. Mayer ◽  
S. Sarig ◽  
N. Garti
Keyword(s):  
Crystal Structure ◽  
Melting Point ◽  
Diffraction Method ◽  
The Other ◽  
Sorbitan Monostearate ◽  
X Ray Diffraction ◽  
Sorbitan Monolaurate ◽  
X Ray ◽  
Crystal Properties ◽  
Long Chain

AbstractThe effect of solid emulsifiers, added at the level of 10%, on the lattice parameters of tristearin and trilaurin, has been studied by powder X-ray diffraction method. The presence of sorbitan monostearate and glycerol-l-stearate affects slightly the lattice constant a in tristearin; on the other hand, although sorbitan monostearate causes an increase in a of trilaurin, glycerol-l-stearate does not. The presence of sorbitan monolaurate and glycerol-l-laurate affect a of trilaurin similarly to the long chain emulsifiers.A correlation between the effect on a and the increase in melting point has been found.The presence of the emulsifier does not alter drastically the lattice dimensions of the fat. The slight dissimilarity in crystal structure between tristearin and trilaurin is confirmed by the diverse effects of the emulsifiers on the internal structure of the fat.

scholarly journals Kandungan Mineral dan Struktur Kristal Batu Sekis

2020 ◽  
Vol 4 (1) ◽  
pp. 24-30
Author(s):  
Muhamad Ragil Setiawan ◽  
Rahmat Nawi Siregar
Keyword(s):  
Crystal Structure ◽  
Data Processing ◽  
Mineral Content ◽  
Diffraction Method ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
Rock Crystal ◽  
X Ray ◽  
Two Samples ◽  
Processing Information

This study aims to determine the mineral content and crystal structure of schist rocks in South Lampung. The method used in this research is the X-ray diffraction method to see the lattice parameters and the crystal structure of the schist rocks. Based on data processing, information was obtained that two main minerals were found, namely quartz and albite minerals. In conclusion, the Albit minerals found in the two samples of rock crystal schists in South Lampung have the same crystal structure and lattice parameters, while the quartz minerals from the two samples have different crystal structures and lattice parameters. Keywords: Lampung, Schis, XRD, Crystal Structure

The determination of the crystal structure of tetrapotassium uranyl tricarbonate by powder X-ray diffraction method

1990 ◽  
Vol 8 (4) ◽  
pp. 313-318 ◽  
Author(s):  
Han Jian-Cheng ◽  
Rong Suo-Bao ◽  
Chen Qi-Ming ◽  
Wu Xin-Ran
Keyword(s):  
Crystal Structure ◽  
Diffraction Method ◽  
X Ray Diffraction ◽  
X Ray

Crystal Structure of ζ2' Martensite in Au-49.5at%Cd Alloy

1991 ◽  
Vol 246 ◽  
Author(s):  
Yutaka Emura ◽  
Takuya Ohba ◽  
Kazuhiro Otsuka
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Crystal Lattice ◽  
Least Squares ◽  
Least Squares Method ◽  
Diffraction Method ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
X Ray ◽  
Lattice Constants

AbstractCrystal structure of the ζ2' martensite in a Au-49.5at%Cd ally has been analyzed by the single crystal x-ray diffraction method. The crystal lattice was trigonal and the lattice constants were a:0.8095(3) and c=o.57940(6) nm. There were 18 atoms in a unit cell. The space group was P3, which was different from that previously determined by Vatanayon and Hehemann. The structure was refined by the full matrix least squares method to a final R factor of 7.8% and a weighted R factor of 4.1%.

Crystal Structure and Fluorescence Characterization of Large π-Conjugated Biphenyl Derivative

2013 ◽  
Vol 850-851 ◽  
pp. 49-52
Author(s):  
Yu Feng Li
Keyword(s):  
Crystal Structure ◽  
Title Compound ◽  
Diffraction Method ◽  
Fluorescence Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Biphenyl Derivative

biphenyl Derivative was synthesized by Wittig-Homer reaction. Its crystal structure was determined by X-ray diffraction method. The fluorescence properties of the title compound in solvents were investigated.

Sign in / Sign up

Export Citation Format

Share Document