Energy-dispersive Laue experiments with X-ray tube and PILATUS detector: precise determination of lattice constants

2019 ◽  
Vol 52 (1) ◽  
pp. 72-93
Author(s):  
Fiodar Kurdzesau
Keyword(s):  
A Priori ◽  
Three Dimensional ◽  
Precise Determination ◽  
Energy Dispersive ◽  
X Ray Diffraction ◽  
Lattice Vector ◽  
X Ray ◽  
Lattice Constants ◽  
Space Pattern ◽  
Measurement Strategies

A PILATUS detector in combination with a conventional sealed X-ray tube was used for the development of the energy-dispersive Laue diffraction technique, which can be applied for precise measurements of single-crystal lattice constants in transmission and reflection modes without moving the sample. Exploiting the ability of PILATUS detectors to suppress counting of X-ray photons below a certain energy threshold allows one to recover the wavelength of diffracted Bragg reflections, reconstruct the three-dimensional reciprocal-space pattern, index X-ray diffraction peaks, and find the orientation and lattice parameters of the crystal without any a priori information about the sample. By making some geometrical assumptions and using a set of fast in situ calibration procedures, it is possible to simultaneously refine lattice constants and hardware correction factors, which simplifies the sample preparation and measurement strategies. Several samples [silicon, quartz, fluorite (CaF2), o′-Al13Co4 quasicrystal approximant, Laves (MgZn2) and Bergman (Mg32(Al,Zn)49) phases] were studied with the developed technique, and 0.01 Å and 0.1° precisions were routinely reached for lattice vector lengths and angles, respectively. The use of the developed methods is only limited by the energy resolution of the PILATUS detector, where lattice vectors with >27 Å length cannot be reliably resolved.

scholarly journals Intragranular strain estimation in far-field scanning X-ray diffraction using a Gaussian process

2021 ◽  
Vol 54 (4) ◽  
Author(s):  
Axel Henningsson ◽  
Johannes Hendriks
Keyword(s):  
Gaussian Process ◽  
Strain Field ◽  
A Priori ◽  
Three Dimensional ◽  
Polycrystalline Materials ◽  
X Ray Diffraction ◽  
Polycrystalline Specimen ◽  
X Ray ◽  
Reconstruction Methods ◽  
Mean Square Errors

A new method for estimation of intragranular strain fields in polycrystalline materials based on scanning three-dimensional X-ray diffraction (scanning 3DXRD) data is presented and evaluated. Given an a priori known anisotropic compliance, the regression method enforces the balance of linear and angular momentum in the linear elastic strain field reconstruction. By using a Gaussian process (GP), the presented method can yield a spatial estimate of the uncertainty of the reconstructed strain field. Furthermore, constraints on spatial smoothness can be optimized with respect to measurements through hyperparameter estimation. These three features address weaknesses discussed for previously existing scanning 3DXRD reconstruction methods and, thus, offer a more robust strain field estimation. The method is twofold validated: firstly by reconstruction from synthetic diffraction data, and secondly by reconstruction of a previously studied tin (Sn) grain embedded in a polycrystalline specimen. Comparison against reconstructions achieved by a recently proposed algebraic inversion technique is also presented. It is found that the GP regression consistently produces reconstructions with lower root-mean-square errors, mean absolute errors and maximum absolute errors across all six components of strain.

Characterization of polycapillary X-ray lens for application in confocal three-dimensional energy-dispersive micro X-ray diffraction experiments

2007 ◽  
Vol 40 (6) ◽  
pp. 1169-1173 ◽  
Author(s):  
Tianxi Sun ◽  
Meirong Zhang ◽  
Xunliang Ding ◽  
Zhiguo Liu ◽  
Xiaoyan Lin ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Depth Resolution ◽  
Energy Dispersive ◽  
Lateral Resolution ◽  
X Ray Diffraction ◽  
Ray Optics ◽  
X Ray

A confocal technology based on polycapillary X-ray optics is proposed to perform three-dimensional energy-dispersive micro X-ray diffraction. A three-dimensional energy-dispersive micro X-ray diffractometer based on a polycapillary focusing X-ray lens (PFXRL) in the excitation channel and a polycapillary parallel X-ray lens (PPXRL) in the detection channel has been designed. At 2\theta = 90^ \circ, the lateral resolution l_X \times l_Y of this diffractometer is 49.7 \times 49.9 \rm \micro m at 7.5 keV, and its depth resolution d_Z is 48.1 \rm \micro m at 8.0 keV. The total resolution of this diffractometer in \Delta d/d is 6.5% at 6.4 keV and 2\theta = 140.2^ \circ.

Ribosome Structural Organization

1974 ◽  
Vol 32 ◽  
pp. 332-333
Author(s):  
James A. Lake
Keyword(s):  
Ribosomal Proteins ◽  
Structural Organization ◽  
Three Dimensional ◽  
Small Subunit ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
Specific Antibodies ◽  
X Ray ◽  
E Coli ◽  
Complete Sequences

The understanding of ribosome structure has advanced considerably in the last several years. Biochemists have characterized the constituent proteins and rRNA's of ribosomes. Complete sequences have been determined for some ribosomal proteins and specific antibodies have been prepared against all E. coli small subunit proteins. In addition, a number of naturally occuring systems of three dimensional ribosome crystals which are suitable for structural studies have been observed in eukaryotes. Although the crystals are, in general, too small for X-ray diffraction, their size is ideal for electron microscopy.

Structural Characterization of Gallbladder Stones Using Energy Dispersive X-ray Spectroscopy and X-ray Diffraction

2018 ◽  
Vol 21 (7) ◽  
pp. 495-500 ◽  
Author(s):  
Hassan A. Almarshad ◽  
Sayed M. Badawy ◽  
Abdalkarem F. Alsharari
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Energy Dispersive ◽  
Spectroscopic Techniques ◽  
X Ray Diffraction ◽  
Major Health Problem ◽  
X Ray ◽  
Gallbladder Stones ◽  
Pure Cholesterol ◽  
Scanning Electron

Aim and Objective: Formation of the gallbladder stones is a common disease and a major health problem. The present study aimed to identify the structures of the most common types of gallbladder stones using X-ray spectroscopic techniques, which provide information about the process of stone formation. Material and Method: Phase and elemental compositions of pure cholesterol and mixed gallstones removed from gallbladders of patients were studied using energy-dispersive X-ray spectroscopy combined with scanning electron microscopy analysis and X-ray diffraction. Results: The crystal structures of gallstones which coincide with standard patterns were confirmed by X-ray diffraction. Plate-like cholesterol crystals with laminar shaped and thin layered structures were clearly observed for gallstone of pure cholesterol by scanning electron microscopy; it also revealed different morphologies from mixed cholesterol stones. Elemental analysis of pure cholesterol and mixed gallstones using energy-dispersive X-ray spectroscopy confirmed the different formation processes of the different types of gallstones. Conclusion: The method of fast and reliable X-ray spectroscopic techniques has numerous advantages over the traditional chemical analysis and other analytical techniques. The results also revealed that the X-ray spectroscopy technique is a promising technique that can aid in understanding the pathogenesis of gallstone disease.

scholarly journals An investigation of polyhedral deformation in two mixed-metal diarsenates: SrZnAs2O7and BaCuAs2O7

2015 ◽  
Vol 71 (4) ◽  
pp. 330-337 ◽  
Author(s):  
Sabina Kovač ◽  
Ljiljana Karanović ◽  
Tamara Đorđević
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
General Formula ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
X Ray ◽  
Open Framework ◽  
Geometrical Characteristics ◽  
Barium Copper

Two isostructural diarsenates, SrZnAs2O7(strontium zinc diarsenate), (I), and BaCuAs2O7[barium copper(II) diarsenate], (II), have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction. The three-dimensional open-framework crystal structure consists of corner-sharingM2O5(M2 = Zn or Cu) square pyramids and diarsenate (As2O7) groups. Each As2O7group shares its five corners with five differentM2O5square pyramids. The resulting framework delimits two types of tunnels aligned parallel to the [010] and [100] directions where the large divalent nine-coordinatedM1 (M1 = Sr or Ba) cations are located. The geometrical characteristics of theM1O9,M2O5and As2O7groups of known isostructural diarsenates, adopting the general formulaM1IIM2IIAs2O7(M1II= Sr, Ba, Pb;M2II= Mg, Co, Cu, Zn) and crystallizing in the space groupP21/n, are presented and discussed.

Selective catalytic reduction of NO by Co-Mn based nanocatalysts

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Vahid Zabihi ◽  
Mohammad Hasan Eikani ◽  
Mehdi Ardjmand ◽  
Seyed Mahdi Latifi ◽  
Alireza Salehirad
Keyword(s):  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Energy Dispersive ◽  
Diffraction Field ◽  
X Ray Diffraction ◽  
X Ray ◽  
Analysis Techniques ◽  
Acidic Sites ◽  
Temperature Window ◽  
Temperature Programmed

Abstract One of the most significant aspects in selective catalytic reduction (SCR) of nitrogen oxides (NOx) is developing suitable catalysts by which the process occurs in a favorable way. At the present work SCR reaction by ammonia (NH3-SCR) was conducted using Co-Mn spinel and its composite with Fe-Mn spinel, as nanocatalysts. The nanocatalysts were fabricated through liquid routes and then their physicochemical properties such as phase composition, degree of agglomeration, particle size distribution, specific surface area and also surface acidic sites have been investigated by X-ray diffraction, Field Emission Scanning Electron Microscope, Energy-dispersive X-ray spectroscopy, energy dispersive spectroscopy mapping, Brunauer–Emmett–Teller, temperature-programmed reduction (H2-TPR) and temperature-programmed desorption of ammonia (NH3-TPD) analysis techniques. The catalytic activity tests in a temperature window of 150–400 °C and gas hourly space velocities of 10,000, 18,000 and 30,000 h−1 revealed that almost in all studied conditions, CoMn2O4/FeMn2O4 nanocomposite exhibited better performance in SCR reaction than CoMn2O4 spinel.

scholarly journals Energy dispersive X-ray diffraction (EDXRD) for operando materials characterization within batteries

2020 ◽  
Vol 22 (37) ◽  
pp. 20972-20989 ◽  
Author(s):  
Amy C. Marschilok ◽  
Andrea M. Bruck ◽  
Alyson Abraham ◽  
Chavis A. Stackhouse ◽  
Kenneth J. Takeuchi ◽  
...  
Keyword(s):  
Materials Characterization ◽  
Energy Dispersive ◽  
System Level ◽  
X Ray Diffraction ◽  
X Ray ◽  
Non Destructive ◽  
Non Destructive Characterization

This review highlights the efficacy of EDXRD as a non-destructive characterization tool in elucidating system-level phenomena for batteries.

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