input4MAUD: an efficient program for automatic two-dimensional diffraction image series input and/or batch refinement withMAUD

2014 ◽  
Vol 47 (6) ◽  
pp. 2081-2085 ◽  
Author(s):  
Lars Raue
Keyword(s):  
Materials Science ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Texture Measurement ◽  
Pole Figures ◽  
Executable File ◽  
Diffraction Peaks ◽  
Efficient Program ◽  
Beta Version ◽  
File Series

In materials science or applied crystallography, X-ray diffraction represents a versatile and useful method with which one can obtain the orientation of single crystals or even the texture of a polycrystalline material. When the investigated sample consists of many phases, or phases of low symmetry, it becomes difficult to measure pole figures from single diffraction peaks. A combined Rietveld–texture analysis with the programMAUDis perfectly suitable to deal with conditions of overlapping diffraction peaks, including those arising from different phases. Even though nearly no alternative toMAUDexists, it is not always easy to use. The input of a file series of two-dimensional diffraction images, for example from a texture measurement, can be time consuming since each individual image must be loaded manually, and only the newest beta version ofMAUDallows semi-automated file input. The new programinput4MAUD, which is presented in this paper, offers a much more efficient way to automate both single and batch file series input intoMAUDas well as the preparation of basic batch refinements withMAUD. input4MAUDis written in Visual C++ and is currently available as a 32-bit statically compiled binary executable file for Windows.

2. Close inspection

2014 ◽  
pp. 22-42
Author(s):  
Christopher Hall
Keyword(s):  
Internal Structure ◽  
Materials Science ◽  
Two Dimensional ◽  
Material Behaviour ◽  
X Ray Diffraction ◽  
Close Inspection ◽  
Robert Hooke ◽  
3 Dimensional ◽  
The Core ◽  
Electron Microscopes

‘Close inspection’ explains that at the core of materials science is the understanding of the internal structure of materials. If we don’t understand the internal structure we shall struggle to explain or to predict material behaviour. If we want to alter the behaviour to make better materials, we probably need to re-engineer the architecture inside. This understanding has been made possible with the development of microscopy, beginning in the 17th century with Robert Hooke and Anton van Leeuwenhoek. Development of X-ray diffraction and electron microscopes has provided atomic resolution leading to improved crystallography and lattice theories for 3-dimensional crystals. Two-dimensional crystals such as graphene and 1-dimensional carbon nanotubes are also described.

scholarly journals A method for accurate texture determination of thin oxide films by glancing-angle laboratory X-ray diffraction

2014 ◽  
Vol 47 (2) ◽  
pp. 575-583 ◽  
Author(s):  
Alistair Garner ◽  
Michael Preuss ◽  
Philipp Frankel
Keyword(s):  
Oxide Films ◽  
X Ray Diffraction ◽  
Aqueous Corrosion ◽  
Texture Measurement ◽  
X Ray ◽  
Peak Broadening ◽  
Glancing Angle ◽  
Thin Oxide Films ◽  
Diffraction Peaks ◽  
Thin Oxide

The present article describes a modification to the standard method of glancing-angle X-ray diffraction for accurate measurement of the texture of thin oxide films. The technique resolves the problems caused by overlapping diffraction peaks originating from multiphase materials with asymmetric unit cells and the peak broadening associated with sample tilt during glancing-angle texture measurement. The entire 2θ range of interest is recorded as a function of sample orientation, and the integrated intensities from different crystallographic planes are extracted from fitted diffraction profiles. The technique allows for pole figures to be plotted from diffraction peaks that could otherwise not be resolved and separates contributions from neighbouring peaks, leading to a more accurate representation of the existing oxide texture. The proposed method has been used for determining texture in a 3 µm layer of monoclinic/tetragonal zirconium oxide grown during aqueous corrosion testing and has been verified by additional synchrotron X-ray diffraction measurements.

Two-Dimensional X-Ray Diffraction for Structure and Stress Analysis

2005 ◽  
Vol 490-491 ◽  
pp. 1-6 ◽  
Author(s):  
Bob B. He ◽  
Ke Wei Xu ◽  
Fei Wang ◽  
Ping Huang
Keyword(s):  
Stress Analysis ◽  
Stress Measurement ◽  
Unit Vector ◽  
Sample Space ◽  
Matrix Transformation ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Texture Measurement ◽  
X Ray ◽  
The Matrix

This paper introduces the recent progress in two-dimensional X-ray diffraction as well as its applications in microstructure and residual stress analysis. Based on the matrix transformation between diffraction space, detector space and sample space, the unit vector of the diffraction vector can be expressed in the sample space corresponding to all the geometric parameters and Bragg conditions. The same transformation matrix can be used for texture and stress analysis. The fundamental equations for both stress measurement and texture measurement are developed with the matrix transformation defined for the two-dimensional diffraction. Stress measurement using twodimensional detector is based on a direct relationship between the stress tensor and the diffraction cone distortion. The two-dimensional detector collects texture data and background values simultaneously for multiple poles and multiple directions.

scholarly journals Texture and Lamellae Distribution Functions in Lamellar Eutectics

1986 ◽  
Vol 6 (4) ◽  
pp. 265-287 ◽  
Author(s):  
H. J. Bunge
Keyword(s):  
Three Dimensional ◽  
Orientation Distribution ◽  
Distribution Functions ◽  
X Rays ◽  
Two Dimensional ◽  
Absorption Factor ◽  
X Ray Diffraction ◽  
Diffraction Vector ◽  
X Ray ◽  
Pole Figures

The crystallographic orientation distribution and the geometrical lamellae orientation distribution in lamellar eutectics are, in general, not independent of each other. The combined orientation-lamellae distribution function depends on five angular parameters. X-ray diffraction in such eutectics may exhibit an anisotropic macroscopic absorption factor if the penetration depth of the X-rays is large compared with their planar size. As a consequence, the reflected X-ray intensity may depend on a third angle γ, i.e. a rotation of the sample about the diffraction vector s additionally to the usual pole figure angles α, β which describe the orientation of the diffraction vector s with respect to the sample coordinate system. It is thus necessary to measure three-dimensional generalized pole figures instead of conventional two-dimensional ones.

Introduction to two-dimensional X-ray diffraction

2003 ◽  
Vol 18 (2) ◽  
pp. 71-85 ◽  
Author(s):  
Bob Baoping He
Keyword(s):  
Diffraction Pattern ◽  
Diffraction Data ◽  
Data Reduction ◽  
Data Interpretation ◽  
Phase Identification ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Texture Measurement ◽  
One Dimensional ◽  
X Ray

Two-dimensional X-ray diffraction refers to X-ray diffraction applications with two-dimensional detector and corresponding data reduction and analysis. The two-dimensional diffraction pattern contains far more information than a one-dimensional profile collected with the conventional diffractometer. In order to take advantage of two-dimensional diffraction, new theories and approaches are necessary to configure the two-dimensional X-ray diffraction system and to analyze the two-dimensional diffraction data. This paper is an introduction to some fundamentals about two-dimensional X-ray diffraction, such as geometry convention, diffraction data interpretation, and advantages of two-dimensional X-ray diffraction in various applications, including phase identification, stress, and texture measurement.

Texture of NiGe(Sn) on Ge(100) and its evolution with Sn content

2021 ◽  
Vol 54 (5) ◽  
pp. 1306-1316
Author(s):  
Andrea Quintero ◽  
Patrice Gergaud ◽  
Tra Nguyen-Thanh ◽  
Jean-Michel Hartmann ◽  
Vincent Reboud ◽  
...  
Keyword(s):  
The Other ◽  
X Ray Diffraction ◽  
Rich Phase ◽  
X Ray ◽  
Pole Figures ◽  
Out Of Plane ◽  
Diffraction Peaks ◽  
The Impact ◽  
Plane Diffraction

The texture of the Ni monostanogermanide phase on a Ge(100) substrate was evaluated during a solid-state reaction, with a focus on the impact of Sn addition. Complementary X-ray diffraction analyses involving in situ X-ray diffraction, in-plane reciprocal space maps (RSMs) and pole figures were used to that end. A sequential growth of the phases for the Ni/Ge(Sn) system was found. An Ni-rich phase formed first, followed by the NiGe(Sn) phase. The NiGe and NiGe(Sn) layers were polycrystalline with different out-of-plane orientations. The number of out-of-plane diffraction peaks decreased with the Sn content, while the preferred orientation changed. In-plane RSM analyses confirmed these results. Sn addition modified the out-of-plane and in-plane orientations. Pole figure analysis revealed that numerous epitaxial texture components were present for the Ni/Ge system, while Sn addition reduced the number of epitaxial texture components. On the other hand, segregated Sn crystallized with an epitaxial alignment with the Ge substrate underneath.

Tubulin structure at intermediate resolution

1995 ◽  
Vol 53 ◽  
pp. 852-853
Author(s):  
K. H. Downing ◽  
S. G. Wolf ◽  
E. Nogales
Keyword(s):  
High Resolution ◽  
Structural Data ◽  
Therapeutic Drug ◽  
Zinc Ions ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Negative Stain ◽  
Functional Mechanisms ◽  
Tubulin Structure

Microtubules are involved in a host of critical cell activities, many of which involve transport of organelles through the cell. Different sets of microtubules appear to form during the cell cycle for different functions. Knowledge of the structure of tubulin will be necessary in order to understand the various functional mechanisms of microtubule assemble, disassembly, and interaction with other molecules, but tubulin has so far resisted crystallization for x-ray diffraction studies. Fortuitously, in the presence of zinc ions, tubulin also forms two-dimensional, crystalline sheets that are ideally suited for study by electron microscopy. We have refined procedures for forming the sheets and preparing them for EM, and have been able to obtain high-resolution structural data that sheds light on the formation and stabilization of microtubules, and even the interaction with a therapeutic drug.Tubulin sheets had been extensively studied in negative stain, demonstrating that the same protofilament structure was formed in the sheets and microtubules. For high resolution studies, we have found that the sheets embedded in either glucose or tannin diffract to around 3 Å.

X-ray microprobe for materials science

1994 ◽  
Vol 52 ◽  
pp. 56-57
Author(s):  
G.E. Ice
Keyword(s):  
Crystallographic Orientation ◽  
Local Structure ◽  
Materials Science ◽  
Chemical Information ◽  
X Ray Diffraction ◽  
Ray Optics ◽  
X Ray ◽  
Novel Materials ◽  
New Information ◽  
Elemental Sensitivity

The increasing availability of synchrotron x-ray sources has stimulated the development of advanced hard x-ray (E≥5 keV) microprobes. With new x-ray optics these microprobes can achieve micron and submicron spatial resolutions. The inherent elemental and crystallographic sensitivity of an x-ray microprobe and its inherently nondestructive and penetrating nature will have important applications to materials science. For example, x-ray fluorescent microanalysis of materials can reveal elemental distributions with greater sensitivity than alternative nondestructive probes. In materials, segregation and nonuniform distributions are the rule rather than the exception. Common interfaces to whichsegregation occurs are surfaces, grain and precipitate boundaries, dislocations, and surfaces formed by defects such as vacancy and interstitial configurations. In addition to chemical information, an x-ray diffraction microprobe can reveal the local structure of a material by detecting its phase, crystallographic orientation and strain.Demonstration experiments have already exploited the penetrating nature of an x-ray microprobe and its inherent elemental sensitivity to provide new information about elemental distributions in novel materials.

Design and Synthesis of Two-Dimensional Covalent Organic Frameworks with Four-Arm Cores: Prediction of Remarkable Ambipolar Charge-Transport Properties

2019 ◽  
Author(s):  
Simil Thomas ◽  
Hong Li ◽  
Raghunath R. Dasari ◽  
Austin Evans ◽  
William Dichtel ◽  
...  
Keyword(s):  
Charge Transport ◽  
Organic Semiconductors ◽  
Density Functional ◽  
Polymer Networks ◽  
Two Dimensional ◽  
Covalent Organic Frameworks ◽  
X Ray Diffraction ◽  
Zinc Porphyrin ◽  
Design And Synthesis ◽  
Predicted Values

<p>We have considered three two-dimensional (2D) π-conjugated polymer networks (i.e., covalent organic frameworks, COFs) materials based on pyrene, porphyrin, and zinc-porphyrin cores connected <i>via</i> diacetylenic linkers. Their electronic structures, investigated at the density functional theory global-hybrid level, are indicative of valence and conduction bands that have large widths, ranging between 1 and 2 eV. Using a molecular approach to derive the electronic couplings between adjacent core units and the electron-vibration couplings, the three π-conjugated 2D COFs are predicted to have ambipolar charge-transport characteristics with electron and hole mobilities in the range of 65-95 cm<sup>2</sup>V<sup>-1</sup>s<sup>-1</sup>. Such predicted values rank these 2D COFs among the highest-mobility organic semiconductors. In addition, we have synthesized the zinc-porphyrin based 2D COF and carried out structural characterization via powder X-ray diffraction and surface area analysis, which demonstrates the feasability of these electroactive networks.</p>

Control of the phase composition of advanced calcium phosphates using an x-ray diffractometer with a curved position-sensitive detector

2020 ◽  
Vol 86 (6) ◽  
pp. 29-35
Author(s):  
V. P. Sirotinkin ◽  
O. V. Baranov ◽  
A. Yu. Fedotov ◽  
S. M. Barinov
Keyword(s):  
Phase Composition ◽  
Calcium Phosphates ◽  
Position Sensitive Detector ◽  
Sensitive Detector ◽  
X Ray Diffraction ◽  
X Ray ◽  
Impurity Phases ◽  
Position Sensitive ◽  
Diffraction Peaks ◽  
Diffraction Patterns

The results of studying the phase composition of advanced calcium phosphates Ca10(PO4)6(OH)2, β-Ca3(PO4)2, α-Ca3(PO4)2, CaHPO4 · 2H2O, Ca8(HPO4)2(PO4)4 · 5H2O using an x-ray diffractometer with a curved position-sensitive detector are presented. Optimal experimental conditions (angular positions of the x-ray tube and detector, size of the slits, exposure time) were determined with allowance for possible formation of the impurity phases during synthesis. The construction features of diffractometers with a position-sensitive detector affecting the profile characteristics of x-ray diffraction peaks are considered. The composition for calibration of the diffractometer (a mixture of sodium acetate and yttrium oxide) was determined. Theoretical x-ray diffraction patterns for corresponding calcium phosphates are constructed on the basis of the literature data. These x-ray diffraction patterns were used to determine the phase composition of the advanced calcium phosphates. The features of advanced calcium phosphates, which should be taken into account during the phase analysis, are indicated. The powder of high-temperature form of tricalcium phosphate strongly adsorbs water from the environment. A strong texture is observed on the x-ray diffraction spectra of dicalcium phosphate dihydrate. A rather specific x-ray diffraction pattern of octacalcium phosphate pentahydrate revealed the only one strong peak at small angles. In all cases, significant deviations are observed for the recorded angular positions and relative intensity of the diffraction peaks. The results of the study of experimentally obtained mixtures of calcium phosphate are presented. It is shown that the graphic comparison of experimental x-ray diffraction spectra and pre-recorded spectra of the reference calcium phosphates and possible impurity phases is the most effective method. In this case, there is no need for calibration. When using this method, the total time for analysis of one sample is no more than 10 min.

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