Characterization of the crystal structure, kinematics, stresses and rotations in angular granular quartz during compaction

Three-dimensional X-ray diffraction (3DXRD), a method for quantifying the position, orientation and elastic strain of large ensembles of single crystals, has recently emerged as an important tool for studying the mechanical response of granular materials during compaction. Applications have demonstrated the utility of 3DXRD and X-ray computed tomography (XRCT) for assessing strains, particle stresses and orientations, inter-particle contacts and forces, particle fracture mechanics, and porosity evolution in situ. Although past studies employing 3DXRD and XRCT have elucidated the mechanics of spherical particle packings and angular particle packings with a small number of particles, there has been limited effort to date in studying angular particle packings with a large number of particles and in comparing the mechanics of these packings with those composed of a large number of spherical particles. Therefore, the focus of the present paper is on the mechanics of several hundred angular particles during compaction using in situ 3DXRD to study the crystal structure, kinematics, stresses and rotations of angular quartz grains. Comparisons are also made between the compaction response of angular grains and that of spherical grains, and stress-induced twinning within individual grains is discussed.

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X-Ray Single Crystal Structural Analysis of Magnetically Oriented Microcrystals

Acta Crystallographica Section A Foundations and Advances ◽

10.1107/s2053273314088615 ◽

2014 ◽

Vol 70 (a1) ◽

pp. C1138-C1138

Author(s):

Chiaki Tsuboi ◽

Kazuki Aburaya ◽

Shingo Higuchi ◽

Fumiko Kimura ◽

Masataka Maeyama ◽

...

Keyword(s):

Molecular Structure ◽

Crystal Structure ◽

Single Crystal ◽

Three Dimensional ◽

Diffraction Measurement ◽

X Ray Diffraction ◽

Data Set ◽

Uv Curable ◽

X Ray

We have developed magnetically oriented microcrystal array (MOMA) technique that enables single crystal X-ray diffraction analyses from microcrystalline powder. In this method, microcrystals suspended in a UV-curable monomer matrix are there-dimensionally aligned by special rotating magnetic field, followed by consolidation of the matrix by photopolymerization. From thus achieved MOMAs, we have been succeeded in crystal structure analysis for some substances [1, 2]. Though MOMA method is an effective technique, it has some problems as follows: in a MOMA, the alignment is deteriorated during the consolidation process. In addition, the sample microcrystals cannot be recovered from a MOMA. To overcome these problems, we performed an in-situ X-ray diffraction measurement using a three-dimensional magnetically oriented microcrystal suspension (3D MOMS) of L-alanine. An experimental setting of the in-situ X-ray measurement of MOMS is schematically shown in the figure. L-alanine microcrystal suspension was poured into a glass capillary and placed on the rotating unit equipped with a pair of neodymium magnets. Rotating X-ray chopper with 10°-slits was placed between the collimator and the suspension. By using this chopper, it was possible to expose the X-ray only when the rotating MOMS makes a specific direction with respect to the impinging X-ray. This has the same effect as the omega oscillation in conventional single crystal measurement. A total of 22 XRD images of 10° increments from 0° to 220° were obtained. The data set was processed by using conventional software to obtain three-dimensional molecular structure of L-alanine. The structure is in good agreement with that reported for the single crystal. R1 and wR2 were 6.53 and 17.4 %, respectively. RMSD value between the determined molecular structure and the reported one was 0.0045 Å. From this result, we conclude that this method can be effective and practical to be used widely for crystal structure analyses.

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Formation and annihilation of stressed deformation twins in magnesium

Communications Materials ◽

10.1038/s43246-020-00105-y ◽

2021 ◽

Vol 2 (1) ◽

Author(s):

Karim Louca ◽

Hamidreza Abdolvand ◽

Charles Mareau ◽

Marta Majkut ◽

Jonathan Wright

Keyword(s):

Mechanical Response ◽

Axial Stress ◽

Three Dimensional ◽

Service Performance ◽

Polycrystalline Materials ◽

X Ray Diffraction ◽

Sign Reversal ◽

X Ray ◽

Hexagonal Close Packed

AbstractThe mechanical response of polycrystalline materials to an externally applied load and their in-service performance depend on the local load partitioning among the constituent crystals. In hexagonal close-packed polycrystals such load partitioning is significantly affected by deformation twinning. Here we report in-situ compression-tension experiments conducted on magnesium specimens to measure the evolution of grain resolved tensorial stresses and formation and annihilation of twins. More than 13000 grains and 1300 twin-parent pairs are studied individually using three-dimensional synchrotron X-ray diffraction. It is shown that at the early stages of plasticity, the axial stress in twins is higher than that of parents, yet twins relax with further loading. While a sign reversal is observed for the resolved shear stress (RSS) acting on the twin habit plane in the parent, the sign of RSS within the majority of twins stays unchanged until twin annihilation during the load reversal. The variations of measured average stresses across parents and twins are also investigated.

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Utilizing broadband X-rays in a Bragg coherent X-ray diffraction imaging experiment

Journal of Synchrotron Radiation ◽

10.1107/s1600577516010523 ◽

2016 ◽

Vol 23 (5) ◽

pp. 1241-1244 ◽

Cited By ~ 4

Author(s):

Wonsuk Cha ◽

Wenjun Liu ◽

Ross Harder ◽

Ruqing Xu ◽

Paul H. Fuoss ◽

...

Keyword(s):

Three Dimensional ◽

Three Dimensions ◽

X Rays ◽

X Ray Diffraction ◽

X Ray ◽

Individual Crystal ◽

Sample Motion ◽

Diffraction Imaging ◽

Individual Grains

A method is presented to simplify Bragg coherent X-ray diffraction imaging studies of complex heterogeneous crystalline materials with a two-stage screening/imaging process that utilizes polychromatic and monochromatic coherent X-rays and is compatible within situsample environments. Coherent white-beam diffraction is used to identify an individual crystal particle or grain that displays desired properties within a larger population. A three-dimensional reciprocal-space map suitable for diffraction imaging is then measured for the Bragg peak of interest using a monochromatic beam energy scan that requires no sample motion, thus simplifyingin situchamber design. This approach was demonstrated with Au nanoparticles and will enable, for example, individual grains in a polycrystalline material of specific orientation to be selected, then imaged in three dimensions while under load.

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Three-Dimensional X-Ray Structural Microscopy Using Polychromatic Microbeams

MRS Bulletin ◽

10.1557/mrs2004.55 ◽

2004 ◽

Vol 29 (3) ◽

pp. 170-176 ◽

Cited By ~ 19

Author(s):

Gene E. Ice ◽

Bennett C. Larson

Keyword(s):

Crystal Structure ◽

Three Dimensional ◽

X Rays ◽

Actual Structure ◽

X Ray ◽

Elastic And Plastic Deformation ◽

Strain Tensors ◽

Microprobe Technique

AbstractIn this article, the authors describe the principle and application of differential-aperture x-ray microscopy (DAXM). This recently developed scanning x-ray microprobe technique uses a confocal or traveling pinhole camera approach to determine the crystal structure, crystallographic orientation, and elastic and plastic strain tensors within bulk materials. The penetrating properties of x-rays make the technique applicable to optically opaque as well as transparent materials, and it is nondestructive; this provides for in situ, submicrometer-resolution characterization of local crystal structure and for measurements of microstructure evolution on mesoscopic length scales from tenths to hundreds of micrometers. Examples are presented that illustrate the use of DAXM to study grain and subgrain morphology, grain-boundary types and networks, and local intra- and intergranular elastic and plastic deformation. Information of this type now provides a direct link between the actual structure and evolution in materials and increasingly powerful computer simulations and multiscale modeling of materials microstructure and evolution.

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Single Crystal Growth of High-Pressure Phases of Ice and Salt Hydrate Far Below the Original Melting Point by Mixing Alcohol: Crystal Structure Determination of Magnesium Chloride Heptahydrate

10.26434/chemrxiv.11345063.v2 ◽

2020 ◽

Author(s):

Keishiro Yamashita ◽

Kazuki Komatsu ◽

Hiroyuki Kagi

Keyword(s):

Crystal Structure ◽

High Pressure ◽

Crystal Growth ◽

Single Crystal ◽

Room Temperature ◽

Growth Technique ◽

Salt Hydrate ◽

X Ray

An crystal-growth technique for single crystal x-ray structure analysis of high-pressure forms of hydrogen-bonded crystals is proposed. We used alcohol mixture (methanol: ethanol = 4:1 in volumetric ratio), which is a widely used pressure transmitting medium, inhibiting the nucleation and growth of unwanted crystals. In this paper, two kinds of single crystals which have not been obtained using a conventional experimental technique were obtained using this technique: ice VI at 1.99 GPa and MgCl<sub>2</sub>·7H<sub>2</sub>O at 2.50 GPa at room temperature. Here we first report the crystal structure of MgCl2·7H2O. This technique simultaneously meets the requirement of hydrostaticity for high-pressure experiments and has feasibility for further in-situ measurements.

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

Acta Crystallographica Section C Structural Chemistry ◽

10.1107/s2053229615005616 ◽

2015 ◽

Vol 71 (4) ◽

pp. 330-337 ◽

Cited By ~ 2

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.

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Morphology and Mechanical Properties of Fossil Diatom Frustules from Genera of Ellerbeckia and Melosira

Nanomaterials ◽

10.3390/nano11061615 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1615

Author(s):

Qiong Li ◽

Jürgen Gluch ◽

Zhongquan Liao ◽

Juliane Posseckardt ◽

André Clausner ◽

...

Keyword(s):

Fracture Behavior ◽

Three Dimensional ◽

Mechanical Tests ◽

Fracture Force ◽

Thickness Change ◽

X Ray ◽

Transmission Electron ◽

Percentage Concentration ◽

Morphology Characterization

Fossil frustules of Ellerbeckia and Melosira were studied using laboratory-based nano X-ray tomography (nano-XCT), transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS). Three-dimensional (3D) morphology characterization using nondestructive nano-XCT reveals the continuous connection of fultoportulae, tube processes and protrusions. The study confirms that Ellerbeckia is different from Melosira. Both genera reveal heavily silicified frustules with valve faces linking together and forming cylindrical chains. For this cylindrical architecture of both genera, valve face thickness, mantle wall thickness and copulae thickness change with the cylindrical diameter. Furthermore, EDS reveals that these fossil frustules contain Si and O only, with no other elements in the percentage concentration range. Nanopores with a diameter of approximately 15 nm were detected inside the biosilica of both genera using TEM. In situ micromechanical experiments with uniaxial loading were carried out within the nano-XCT on these fossil frustules to determine the maximal loading force under compression and to describe the fracture behavior. The fracture force of both genera is correlated to the dimension of the fossil frustules. The results from in situ mechanical tests show that the crack initiation starts either at very thin features or at linking structures of the frustules.

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PHASE TRANSITION IN LAYERED PEROVSKITE LIKE MANGANATE Ca3Mn2O7 UNDER HIGH PRESSURE

International Journal of Modern Physics B ◽

10.1142/s0217979201007117 ◽

2001 ◽

Vol 15 (18) ◽

pp. 2491-2497 ◽

Cited By ~ 1

Author(s):

J. L. ZHU ◽

L. C. CHEN ◽

R. C. YU ◽

F. Y. LI ◽

J. LIU ◽

...

Keyword(s):

Crystal Structure ◽

High Pressure ◽

Diamond Anvil Cell ◽

The Other ◽

Layered Perovskite ◽

X Ray Diffraction ◽

Two Phase ◽

X Ray ◽

Diamond Anvil

In situ high pressure energy dispersive X-ray diffraction measurements on layered perovskite-like manganate Ca 3 Mn 2 O 7 under pressures up to 35 GPa have been performed by using diamond anvil cell with synchrotron radiation. The results show that the structure of layered perovskite-like manganate Ca 3 Mn 2 O 7 is unstable under pressure due to the easy compression of NaCl-type blocks. The structure of Ca 3 Mn 2 O 7 underwent two phase transitions under pressures in the range of 0~35 GPa. One was at about 1.3 GPa with the crystal structure changing from tetragonal to orthorhombic. The other was at about 9.5 GPa with the crystal structure changing from orthorhombic back to another tetragonal.

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