scholarly journals Removing multiple outliers and single-crystal artefacts from X-ray diffraction computed tomography data

2015 ◽  
Vol 48 (6) ◽  
pp. 1943-1955 ◽  
Author(s):  
Antonios Vamvakeros ◽  
Simon D. M. Jacques ◽  
Marco Di Michiel ◽  
Vesna Middelkoop ◽  
Christopher K. Egan ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Single Crystal ◽  
Tomographic Reconstruction ◽  
Projection Data ◽  
Data Sets ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns ◽  
Tomography Data

This paper reports a simple but effective filtering approach to deal with single-crystal artefacts in X-ray diffraction computed tomography (XRD-CT). In XRD-CT, large crystallites can produce spots on top of the powder diffraction rings, which, after azimuthal integration and tomographic reconstruction, lead to line/streak artefacts in the tomograms. In the simple approach presented here, the polar transform is taken of collected two-dimensional diffraction patterns followed by directional median/mean filtering prior to integration. Reconstruction of one-dimensional diffraction projection data sets treated in such a way leads to a very significant improvement in reconstructed image quality for systems that exhibit powder spottiness arising from large crystallites. This approach is not computationally heavy which is an important consideration with big data sets such as is the case with XRD-CT. The method should have application to two-dimensional X-ray diffraction data in general where such spottiness arises.

scholarly journals DLSR: a solution to the parallax artefact in X-ray diffraction computed tomography data

2020 ◽  
Vol 53 (6) ◽  
pp. 1531-1541
Author(s):  
A. Vamvakeros ◽  
A. A. Coelho ◽  
D. Matras ◽  
H. Dong ◽  
Y. Odarchenko ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Tomographic Reconstruction ◽  
Scale Up ◽  
Lattice Parameter ◽  
Chemical Information ◽  
X Rays ◽  
X Ray Diffraction ◽  
Major Barrier ◽  
X Ray ◽  
Tomography Data

A new tomographic reconstruction algorithm is presented, termed direct least-squares reconstruction (DLSR), which solves the well known parallax problem in X-ray-scattering-based experiments. The parallax artefact arises from relatively large samples where X-rays, scattered from a scattering angle 2θ, arrive at multiple detector elements. This phenomenon leads to loss of physico-chemical information associated with diffraction peak shape and position (i.e. altering the calculated crystallite size and lattice parameter values, respectively) and is currently the major barrier to investigating samples and devices at the centimetre level (scale-up problem). The accuracy of the DLSR algorithm has been tested against simulated and experimental X-ray diffraction computed tomography data using the TOPAS software.

DATAD: a Python-based X-ray diffraction simulation code for arbitrary texture and arbitrary deformation

2021 ◽  
Vol 54 (2) ◽  
pp. 686-696
Author(s):  
J. W. Huang ◽  
Y. Y. Zhang ◽  
S. C. Hu ◽  
Y. Cai ◽  
S. N. Luo
Keyword(s):  
Single Crystal ◽  
Applied Strain ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Simulation Code ◽  
Polycrystalline Specimen ◽  
Basic Principles ◽  
X Ray ◽  
Deformation State ◽  
Diffraction Patterns

DATAD, a Python-based X-ray diffraction simulation code, has been developed for simulating one- and two-dimensional diffraction patterns of a polycrystalline specimen with an arbitrary texture under an arbitrary deformation state and an arbitrary detection geometry. Pixelated planar and cylindrical detectors can be used. The basic principles and key components of the code are presented along with the usage of DATAD. As validation and application cases, X-ray diffraction patterns of single-crystal and polycrystalline specimens with or without texture, or applied strain, on a planar or cylindrical detector are simulated.

The software packageANAELUfor X-ray diffraction analysis using two-dimensional patterns

2010 ◽  
Vol 44 (1) ◽  
pp. 241-246 ◽  
Author(s):  
Luis Fuentes-Montero ◽  
Maria Elena Montero-Cabrera ◽  
Luis Fuentes-Cobas
Keyword(s):  
Single Crystal ◽  
Diffraction Analysis ◽  
Software Package ◽  
Inverse Pole Figure ◽  
Two Dimensional ◽  
Axially Symmetric ◽  
X Ray Diffraction ◽  
X Ray ◽  
Measurement And Analysis ◽  
Diffraction Patterns

A new software package for interpreting two-dimensional diffraction diagrams is presented. The application capabilities include representation of single- and polycrystal structures with an inverse pole figure treatment of texture phenomena, measurement and analysis of diffraction signals, and different approaches to the modelling of two-dimensional diffraction patterns obtained from both single-crystal and polycrystalline samples. Particular consideration is given to the effect of axially symmetric textures on two-dimensional diffraction patterns. An example showing the capabilities of the software is presented.

Plastic deformations in kyanites by tectonometamorphic processes: a single-crystal X-ray diffraction study

2009 ◽  
Vol 73 (3) ◽  
pp. 359-371 ◽  
Author(s):  
G. D. Gatta ◽  
N. Rotiroti ◽  
M. Zucali
Keyword(s):  
Single Crystal ◽  
X Ray Diffraction ◽  
Plastic Deformations ◽  
X Ray ◽  
Deformational History ◽  
Significant Difference ◽  
Elliptical Section ◽  
History Of ◽  
Diffraction Patterns ◽  
Two Stages

AbstractThe crystalch emistry and crystal structure of naturalky anite crystals from the Eclogitic Micaschists Complex of the Sesia-Lanzo Zone, Western Italian Alps, have been investigated by means of optical microscopy, wavelength dispersive X-ray microanalysis, and single-crystal X-ray diffraction. The association of kyanite + garnet + phengitic-mica + chloritoid suggests that the eclogite-facies stages occurred at P ≤ 2.1 GPa and T ≤ 650ºC. Kyanite grains are large (cm-sized) porphyroblasts grown dynamically during one of the deformational events related to the subduction of the Austroalpine continentalcr ust. Under the polarizing microscope, kyanite grains show almost homogeneous cores, whereas rims are sometimes symplectitic aggregates of quartz and kyanite, confirming at least two stages of growth most likely related to the multistage deformational history of these rocks. Chemical analysis shows that Fe3+ is the major substituting cation for Al3+, ranging between 0.038 and 0.067 a.p.f.u.The single-crystal X-ray diffraction investigation of the kyanites shows severely textured patterns on the (h0l)*-plane. Such evidence is not observed in the unwarped diffraction patterns on (0kl)* and (hk0)*. The most significant difference between the structuralp arameters refined in this study, with respect to those of previously published unstrained gem-quality crystals, concerns the displacement parameters. The anisotropic displacement ellipsoids of all the atomic sites are significantly larger than those previously described, and systematically oriented with the largest elliptical section almost perpendicular to [010]. The larger ellipsoids in the kyanite crystal investigated here reflect the displacement of the centre of gravity of the electron distribution, rather than an anomalous atomic thermal motion. The magnitude and orientation of the displacement parameters and the textured/strained diffraction pattern may be the result of two combined effects: (1) that the kyanite crystals are actually composed of several blocks; (2) the crystals are affected by a pervasive residual strain, as a result of tectonometamorphic plastic deformations and re-crystallization.

Synthesis, Structure and Properties of Two-Dimensional Coordination Polymer Based on 3,5-di(benzimidazol-1-yl)pyridine

2020 ◽  
Vol 42 (2) ◽  
pp. 249-249
Author(s):  
Guo Jun Wu Guo Jun Wu
Keyword(s):  
Infrared Spectroscopy ◽  
Coordination Polymer ◽  
Single Crystal ◽  
Photocatalytic Degradation ◽  
Elemental Analysis ◽  
Solvothermal Reaction ◽  
Two Dimensional ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
X Ray

[Cu(L)(AIP)·1.5H2O]n (1) [L= 3,5-di(benzimidazol-1-yl)pyridine, H2AIP= 5-aminoisophthalic acid] was prepared by the solvothermal reaction, which was characterized by single-crystal X–ray diffraction, infrared spectroscopy, and elemental analysis. 1 exhibits an infinite two dimensional [Cu(AIP)]n sheet parallel to (0 1 1) crystal plane. Furthermore, complex 1 displays good photocatalytic degradation of methyl blue (MB).

New crystal structures in the realm of 5,5′-azotetrazolates

2015 ◽  
Vol 70 (2) ◽  
pp. 125-134 ◽  
Author(s):  
Martin Lampl ◽  
Gerhard Laus ◽  
Doris E. Braun ◽  
Volker Kahlenberg ◽  
Klaus Wurst ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Single Crystal ◽  
Crystal Structures ◽  
Organic Cations ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Diffraction Patterns

AbstractThe preparation of six new 5,5′-azotetrazolates with organic cations is reported. Differential scanning calorimetry of all compounds showed exothermic decompositions. The crystal structures of the six 5,5′-azotetrazolates were determined by single-crystal X-ray diffraction analyses. The phase purities of the bulk samples were confirmed by Pawley fits of the experimental and calculated powder X-ray diffraction patterns.

Exfoliated single molecular layers of Mn0.8PS3 and Cd0.8PS3

2005 ◽  
Vol 20 (5) ◽  
pp. 1107-1112 ◽  
Author(s):  
R.F. Frindt ◽  
D. Yang ◽  
P. Westreich
Keyword(s):  
Ion Exchange ◽  
Structure Factor ◽  
Single Layer ◽  
Layered Compounds ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vacancy Ordering ◽  
Diffraction Patterns ◽  
Molecular Layers

The layered compounds MnPS3 and CdPS3 were exfoliated to form single molecular layers of Mn0.8PS3 and Cd0.8PS3 in suspension in water by ion exchange. The x-ray diffraction patterns of the two single-layer suspensions showed profound differences in some of the Bragg peaks, and we demonstrated that the differences are not due to the quality or size of the single layers, but are caused by structure factor modulations of the Warren tail for two-dimensional systems. We also demonstrated that the Cd or Mn vacancies generated in the exfoliation process are not ordered at long range, in contrast to an earlier report of vacancy ordering on intercalated MnPS3.

Synchrotron radiation study of yttria-stabilized zirconia, Zr0.758Y0.242O1.879

1999 ◽  
Vol 55 (5) ◽  
pp. 726-735 ◽  
Author(s):  
N. Ishizawa ◽  
Y. Matsushima ◽  
M. Hayashi ◽  
M. Ueki
Keyword(s):  
Synchrotron Radiation ◽  
Single Crystal ◽  
Yttria Stabilized Zirconia ◽  
Data Sets ◽  
X Ray Diffraction ◽  
Stabilized Zirconia ◽  
X Ray ◽  
Ideal Position ◽  
Fluorite Type ◽  
The Ideal

The fluorite-related cubic structure of yttria-stabilized zirconia, Zr0.75 8Y0.24 2O1.87 9, has been studied by single-crystal X-ray diffraction using synchrotron radiation and by EXAFS. Two diffraction data sets obtained at X-ray energies of 512 and 10 eV below the Y K edge revealed that in the average structure Zr atoms are displaced from the origin of the space group Fm3¯m along 〈111〉 by 0.19 Å, while Y atoms reside at the origin. Approximately 48% of the O atoms occupy the ideal position in the fluorite-type structure, while 43% of O atoms are displaced from the ideal position along 〈001〉 by 0.31 Å. The remaining 9% of O atoms are presumably sited at interstitial positions. Local structures around Zr and Y are investigated by combining the results of single-crystal X-ray diffraction and EXAFS studies.

Simulations of X-ray diffraction of shock-compressed single-crystal tantalum with synchrotron undulator sources

2018 ◽  
Vol 25 (3) ◽  
pp. 748-756 ◽  
Author(s):  
M. X. Tang ◽  
Y. Y. Zhang ◽  
J. C. E ◽  
S. N. Luo
Keyword(s):  
Single Crystal ◽  
Large Scale ◽  
Incident Beam ◽  
Wave Structure ◽  
X Ray Diffraction ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
Diffraction Patterns ◽  
Case Transmission ◽  
Dynamics Simulations

Polychromatic synchrotron undulator X-ray sources are useful for ultrafast single-crystal diffraction under shock compression. Here, simulations of X-ray diffraction of shock-compressed single-crystal tantalum with realistic undulator sources are reported, based on large-scale molecular dynamics simulations. Purely elastic deformation, elastic–plastic two-wave structure, and severe plastic deformation under different impact velocities are explored, as well as an edge release case. Transmission-mode diffraction simulations consider crystallographic orientation, loading direction, incident beam direction, X-ray spectrum bandwidth and realistic detector size. Diffraction patterns and reciprocal space nodes are obtained from atomic configurations for different loading (elastic and plastic) and detection conditions, and interpretation of the diffraction patterns is discussed.

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