scholarly journals X-Ray Microbeam Measurement of Local Texture and Strain in Metals

1999 ◽  
Vol 563 ◽  
Author(s):  
Jin-Seok Chung ◽  
N. Tamura ◽  
G. E. Ice ◽  
B. C. Larson ◽  
J. D. Budai
Keyword(s):  
Fresnel Zone ◽  
Strain Tensor ◽  
Unit Cell ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Local Texture ◽  
Ccd Detector ◽  
Photon Source ◽  
Strained Material

AbstractSynchrotron x-ray sources provide high-brilliance beams that can be focused to submicron sizes with Fresnel zone-plate and x-ray mirror optics. With these intense, tunable or broadbandpass x-ray microbeams, it is now possible to study texture and strain distributions in surfaces, and in buried or encapsulated thin films. The full strain tensor and local texture can be determined by measuring the unit cell parameters of strained material. With monochromatic or tunable radiation, at least three independent reflections are needed to determine the orientation and unit cell parameters of an unknown crystal. With broadbandpass or white radiation, at least four reflections and one measured energy are required to determine the orientation and the unit cell parameters of an unknown crystal. Routine measurement of local texture and strain is made possible by automatic indexing of the Laue reflections combined with precision calibration of the monochromator-focusing mirrors-CCD detector system. Methods used in implementing these techniques on the MHATT-CAT beam line at the Advanced Photon Source will be discussed.

scholarly journals Crystal Structure Refinements of Four Monazite Samples from Different Localities

Minerals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1028 ◽  
Author(s):  
M. Mashrur Zaman ◽  
Sytle M. Antao
Keyword(s):  
Crystal Structure ◽  
Electron Probe ◽  
Unit Cell Volume ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Large Unit Cell ◽  
A Site

This study investigates the crystal chemistry of monazite (APO4, where A = Lanthanides = Ln, as well as Y, Th, U, Ca, and Pb) based on four samples from different localities using single-crystal X-ray diffraction and electron-probe microanalysis. The crystal structure of all four samples are well refined, as indicated by their refinement statistics. Relatively large unit-cell parameters (a = 6.7640(5), b = 6.9850(4), c = 6.4500(3) Å, β = 103.584(2)°, and V = 296.22(3) Å3) are obtained for a detrital monazite-Ce from Cox’s Bazar, Bangladesh. Sm-rich monazite from Gunnison County, Colorado, USA, has smaller unit-cell parameters (a = 6.7010(4), b = 6.9080(4), c = 6.4300(4) Å, β = 103.817(3)°, and V = 289.04(3) Å3). The a, b, and c unit-cell parameters vary linearly with the unit-cell volume, V. The change in the a parameter is large (0.2 Å) and is related to the type of cations occupying the A site. The average <A-O> distances vary linearly with V, whereas the average <P-O> distances are nearly constant because the PO4 group is a rigid tetrahedron.

Compressibility of β-As4S4: an in situ high-pressure single-crystal X-ray study

2012 ◽  
Vol 76 (4) ◽  
pp. 963-973 ◽  
Author(s):  
G. O. Lepore ◽  
T. Boffa Ballaran ◽  
F. Nestola ◽  
L. Bindi ◽  
D. Pasqual ◽  
...  
Keyword(s):  
Pressure Range ◽  
Substantial Reduction ◽  
Structural Data ◽  
Unit Cell ◽  
Van Der Waals Interactions ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Intermolecular Distances

AbstractAmbient temperature X-ray diffraction data were collected at different pressures from two crystals of β-As4S4, which were made by heating realgar under vacuum at 295ºC for 24 h. These data were used to calculate the unit-cell parameters at pressures up to 6.86 GPa. Above 2.86 GPa, it was only possible to make an approximate measurement of the unit-cell parameters. As expected for a crystal structure that contains molecular units held together by weak van der Waals interactions, β-As4S4 has an exceptionally high compressibility. The compressibility data were fitted to a third-order Birch–Murnaghan equation of state with a resulting volume V0 = 808.2(2) Å3, bulk modulus K0 = 10.9(2) GPa and K' = 8.9(3). These values are extremely close to those reported for the low-temperature polymorph of As4S4, realgar, which contains the same As4S4 cage-molecule. Structural analysis showed that the unit-cell contraction is due mainly to the reduction in intermolecular distances, which causes a substantial reduction in the unit-cell volume (∼21% at 6.86 GPa). The cage-like As4S4 molecules are only slightly affected. No phase transitions occur in the pressure range investigated.Micro-Raman spectra, collected across the entire pressure range, show that the peaks associated with As–As stretching have the greatest pressure dependence; the S–As–S bending frequency and the As–S stretching have a much weaker dependence or no variation at all as the pressure increases; this is in excellent agreement with the structural data.

Crystallization and preliminary X-ray studies of sialidase L from the leech Macrobdella decora

1998 ◽  
Vol 54 (1) ◽  
pp. 111-113 ◽  
Author(s):  
Yu Luo ◽  
Min-yuan Chou ◽  
Su-chen Li ◽  
Yu-teh Li ◽  
Ming Luo
Keyword(s):  
Escherichia Coli ◽  
Unit Cell ◽  
Data Sets ◽  
Molecular Replacement ◽  
Unit Cell Parameters ◽  
Solvent Content ◽  
X Ray ◽  
Cell Parameters ◽  
Mercury Derivative ◽  
Macrobdella Decora

Functional monomeric 83 kDa sialidase L, a NeuAcα2→3Gal-specific sialidase from Macrobdella leech, was expressed in Escherichia coli and readily crystallized by a macroseeding technique. The crystal belongs to space group P1 with unit-cell parameters a = 46.4, b = 69.3, c = 72.5 Å, α = 113.5, β = 95.4 and γ = 107.3°. There is one molecule per unit cell, giving a Vm = 2.4 Å3 Da−1 and a solvent content of 40%. Native and mercury-derivative data sets were collected to 2.0 Å resolution. Threading and molecular-replacement calculations confirmed the existence of a bacterial sialidase-like domain.

X-ray powder diffraction data for tetrazene nitrate monohydrate, C2H9N11O4

2021 ◽  
pp. 1-3
Author(s):  
J. Maixner ◽  
J. Ryšavý
Keyword(s):  
Cell Volume ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Unit Cell Volume ◽  
Unit Cell ◽  
Powder Diffraction Data ◽  
Unit Cell Parameters ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters

X-ray powder diffraction data, unit-cell parameters, and space group for tetrazene nitrate monohydrate, C2H9N11O4, are reported [a = 5.205(1) Å, b = 13.932(3) Å, c = 14.196(4) Å, β = 97.826(3)°, unit-cell volume V = 1019.8(4) Å3, Z = 4, and space group P21/c]. All measured lines were indexed and are consistent with the P21/c space group. No detectable impurities were observed.

Pb-Sb zrudnění z Antimonitové žíly, důl Rudolf, Bohutín (Česká republika)

2021 ◽  
Vol 29 (2) ◽  
pp. 275-280
Author(s):  
Pavel Škácha ◽  
Jiří Sejkora
Keyword(s):  
Czech Republic ◽  
Chemical Composition ◽  
Empirical Formula ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Ore District ◽  
Archive Material

The Pb-Sb mineralization with dominant stibnite and plagionite and associated semseyite and zinkenite was found in an archive material collected at the Antimonitová vein, Bohutín, Březové Hory ore district (Czech Republic). Plagionite forms subhedral aggregates up to 1 mm in size. The unit-cell parameters of plagionite for monoclinic space group C2/c refined from the X-ray powder data are: a 13.4890(17), b 11.8670(14), c 19.997(2) Å, β 107.199(8)° and V 3057.9(6) Å3. Its chemical composition (average of 26 analyses, based on 30 apfu) corresponds to the empirical formula Pb5.02Sb8.15S16.82. Associated zinkenite is forming subhedral crystals up to 1 mm in size. Its empirical formula can be expressed as (Cu0.25Ag0.02Fe0.01)Σ0.28Pb9.22Sb22.19S41.31 (average of 26 analyses, based on 73 apfu). Semseyite aggregates have the empirical formula (Pb8.72Fe0.14)8.86Sb8.42S20.73 (average of 11 analyses, based on 38 apfu).

scholarly journals Crystallization and X-ray diffraction analysis of native and selenomethionine-substituted PhyH-DI fromBacillussp. HJB17

2017 ◽  
Vol 73 (11) ◽  
pp. 607-611
Author(s):  
Fang Lu ◽  
Bei Zhang ◽  
Yong Liu ◽  
Ying Song ◽  
Gangxing Guo ◽  
...  
Keyword(s):  
Unit Cell ◽  
Diffusion Method ◽  
Data Sets ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Solvent Content ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters

Phytases are phosphatases that hydrolyze phytates to less phosphorylatedmyo-inositol derivatives and inorganic phosphate. β-Propeller phytases, which are very diverse phytases with improved thermostability that are active at neutral and alkaline pH and have absolute substrate specificity, are ideal substitutes for other commercial phytases. PhyH-DI, a β-propeller phytase fromBacillussp. HJB17, was found to act synergistically with other single-domain phytases and can increase their efficiency in the hydrolysis of phytate. Crystals of native and selenomethionine-substituted PhyH-DI were obtained using the vapour-diffusion method in a condition consisting of 0.2 Msodium chloride, 0.1 MTris pH 8.5, 25%(w/v) PEG 3350 at 289 K. X-ray diffraction data were collected to 3.00 and 2.70 Å resolution, respectively, at 100 K. Native PhyH-DI crystals belonged to space groupC121, with unit-cell parametersa = 156.84,b = 45.54,c = 97.64 Å, α = 90.00, β = 125.86, γ = 90.00°. The asymmetric unit contained two molecules of PhyH-DI, with a corresponding Matthews coefficient of 2.17 Å3 Da−1and a solvent content of 43.26%. Crystals of selenomethionine-substituted PhyH-DI belonged to space groupC2221, with unit-cell parametersa = 94.71,b= 97.03,c= 69.16 Å, α = β = γ = 90.00°. The asymmetric unit contained one molecule of the protein, with a corresponding Matthews coefficient of 2.44 Å3 Da−1and a solvent content of 49.64%. Initial phases for PhyH-DI were obtained from SeMet SAD data sets. These data will be useful for further studies of the structure–function relationship of PhyH-DI.

X-ray powder diffraction study of ZnGa2Te4

2002 ◽  
Vol 17 (1) ◽  
pp. 41-43 ◽  
Author(s):  
Rashmi ◽  
U. Dhawan
Keyword(s):  
Diffraction Study ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Unit Cell ◽  
Powder Diffraction Data ◽  
Unit Cell Parameters ◽  
Tetrahedral Structure ◽  
X Ray ◽  
Cell Parameters ◽  
Ray Density

ZnGa2Te4 was found to crystallize in a defect tetrahedral structure with possible space group I4(82) with Z=2. Complete X-ray powder diffraction data were obtained and the unit cell parameters a and c and X-ray density were calculated. These were a=0.5930(1) nm, c=1.1859(3) nm, and Dx=5.7×103 kg/m3.

Crystallization and preliminary X-ray study of two crystal forms of Klebsiella oxytoca diol dehydratase–cyanocobalamin complex

1999 ◽  
Vol 55 (4) ◽  
pp. 907-909 ◽  
Author(s):  
Jun Masuda ◽  
Tetsuya Yamaguchi ◽  
Takamasa Tobimatsu ◽  
Tetsuo Toraya ◽  
Kyoko Suto ◽  
...  
Keyword(s):  
Klebsiella Oxytoca ◽  
Crystal Form ◽  
Unit Cell ◽  
Unit Cell Parameters ◽  
Crystal Forms ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
Diol Dehydratase ◽  
Replacement Method

Two crystal forms of Klebsiella oxytoca diol dehydratase complexed with cyanocobalamin have been obtained and preliminary crystallographic experiments have been performed. The crystals belong to two different space groups, depending on the crystallization conditions. One crystal (form I) belongs to space group P212121 with unit-cell parameters a = 76.2, b = 122.3, c = 209.6 Å, and diffracts to 2.2 Å resolution using an X-ray beam from a synchrotron radiation source. The other crystal (form II) belongs to space group P21 with unit-cell parameters a = 75.4, b = 132.7, c = 298.8 Å, β = 91.9°, and diffracts to 3.0 Å resolution. For the purpose of structure determination, a heavy-atom derivative search was carried out and some mercuric derivatives were found to be promising. Structure analysis by the multiple isomorphous replacement method is now under way.

X-ray powder diffraction data for ertapenem side chain, C20H19N3O7S

2017 ◽  
Vol 32 (3) ◽  
pp. 203-205
Author(s):  
Xiang Lin ◽  
Wei Ling Zhuo ◽  
Qiao Hong Du ◽  
Xi Lin Peng ◽  
Hui Li
Keyword(s):  
Powder Diffraction ◽  
Diffraction Data ◽  
Unit Cell Volume ◽  
Unit Cell ◽  
Side Chain ◽  
Powder Diffraction Data ◽  
Unit Cell Parameters ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters

X-ray powder diffraction data, unit-cell parameters, and space group for ertapenem side chain, C20H19N3O7S, are reported [a = 4.907(6) Å, b = 18.686(3) Å, c = 22.071(1) Å, α = γ = 90°, β = 90.759(5)°, unit-cell volume V = 2023.82 Å3, Z = 4, ρcal = 1.462 g cm−3, and space group P21/c]. All measured lines were indexed and are consistent with the P21/c space group. No detectable impurity was observed.

X-ray powder diffraction data for copper(II), bis[(2E)-3-methoxy-2-[(2,6-dimethylphenyl)imino]-4-[(2,6-dimethylphenyl)imino-κN]-3-pentanolato-κO] complex

2013 ◽  
Vol 28 (4) ◽  
pp. 296-298
Author(s):  
R. Pažout ◽  
J. Maixner ◽  
A.S. Jones ◽  
J. Merna
Keyword(s):  
Cell Volume ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Unit Cell Volume ◽  
Unit Cell ◽  
Powder Diffraction Data ◽  
Unit Cell Parameters ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters

X-ray powder diffraction data, unit-cell parameters, and space group for a new bis(β-diiminato) Cu(II) complex, C44H54CuN4O4, are reported [a = 8.683(3) Å, b = 11.216(3) Å, c = 11.753(4) Å, α = 66.27(3), β = 84.61(3), γ = 78.85(3), unit-cell volume V = 1027.77 Å3, Z = 1, and space group P-1]. All measured lines were indexed and are consistent with the P-1 space group. No detectable impurity was observed.

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