Incredible internal strains within a biogenic single crystal viewed by X-ray diffraction tomography

AbstractThe dorsal arm plates (DAPs) of the Ophiocoma Wendtii brittle star are highly functional single crystalline biominerals whose optimized structure and nanostructure enable them to fullfill mechanical and optical functions in the organism. Here, a large DAP bulk piece is characterized by means of synchrotron X-ray Diffraction Tomography (XRDT). This non-destructive crystallographic characterization revealed an astounding feature: the presence of very high compressive strains which relax when the mineral is cracked or grinded into a powder. Thus, previous destructive characterization techniques did not allow their detection. We attribute the compressive strains to the previously identified high-Mg calcite particles, which are coherently included and thereby compress the low-Mg calcite matrix. The measured slice contained both the bulk DAP sample as well as DAP powder. The data generated by the bulk piece could be separated from those by the powder, and the latter was used to calibrate and interprete the former. This study reveals yet another awe-inspiring feature of a biogenic structure, highlights the importance of non-destructive crystallographic characterization for biominerals, and exemplifies the potential of XRDT use in studying a single crystalline material, as well as the advantage of complementary measurement of bulk and powder for data calibration and interpretation.

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Applying multivariate analysis to x-ray diffraction computed tomography: the study of medieval applied brocades.

Journal of Analytical Atomic Spectrometry ◽

10.1039/d1ja00143d ◽

2021 ◽

Author(s):

Pierre Bordet ◽

Florian Kergourlay ◽

Ariane Pinto ◽

NIls Blanc ◽

Pauline Martinetto

Keyword(s):

Computed Tomography ◽

Multivariate Analysis ◽

Cultural Heritage ◽

Heterogeneous Materials ◽

Diffraction Tomography ◽

X Ray Diffraction ◽

X Ray ◽

Non Destructive

X-ray diffraction tomography is a well-developed technique to study the structure of heterogeneous materials which makes it a tool of choice for the non-destructive investigation of cultural heritage microsamples. Characterizing...

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Development of a novel apparatus for experiments in soft X-ray diffraction imaging and diffraction tomography

Journal de Physique IV (Proceedings) ◽

10.1051/jp4:200300022 ◽

2003 ◽

Vol 104 ◽

pp. 27-30 ◽

Cited By ~ 2

Author(s):

T. Beetz ◽

C. Jacobsen ◽

C.-C. Kao ◽

J. Kirz ◽

O. Mentes ◽

...

Keyword(s):

Diffraction Tomography ◽

X Ray Diffraction ◽

X Ray ◽

Diffraction Imaging

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Highlights in the history of X-ray topography1

Zeitschrift für Kristallographie - Crystalline Materials ◽

10.1524/zkri.1995.210.6.394 ◽

1995 ◽

Vol 210 (6) ◽

Author(s):

A. R. Lang

Keyword(s):

Magnetic Domain ◽

Diffraction Theory ◽

Dislocation Loops ◽

X Ray Diffraction ◽

X Ray ◽

Domain Structures ◽

Structure Factors ◽

History Of ◽

Dislocation Sources ◽

Non Destructive

AbstractX-ray topography provides a non-destructive method of mapping point-by-point variations in orientation and reflecting power within crystals. The discovery, made by several workers independently, that in nearly perfect crystals it was possible to detect individual dislocations by X-ray diffraction contrast started an epoch of rapid exploitation of X-ray topography as a new, general method for assessing crystal perfection. Another discovery, that of X-ray Pendellösung, led to important theoretical developments in X-ray diffraction theory and to a new and precise method for measuring structure factors on an absolute scale. Other highlights picked out for mention are studies of Frank-Read dislocation sources, the discovery of long dislocation helices and lines of coaxial dislocation loops in aluminium, of internal magnetic domain structures in Fe-3 wt.% Si, and of stacking faults in silicon and natural diamonds.

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Defect-Mediated Conductivity Enhancements in Na3-xPn1-xWxS4 (Pn = P, Sb) using Aliovalent Substitutions

10.26434/chemrxiv.9943961.v2 ◽

2019 ◽

Author(s):

Till Fuchs ◽

Sean Culver ◽

Paul Till ◽

Wolfgang Zeier

Keyword(s):

Ionic Conductivity ◽

Vacancy Concentration ◽

Sodium Ion ◽

High Ionic Conductivity ◽

Ionic Conductors ◽

X Ray Diffraction ◽

X Ray ◽

Solid State Batteries ◽

Ion Conducting ◽

Very High

The sodium-ion conducting family of Na3PnS4, with Pn = P, Sb, have gained interest for the use in solid-state batteries due to their high ionic conductivity. However, significant improvements to the conductivity have been hampered by the lack of aliovalent dopants that can introduce vacancies into the structure. Inspired by the need for vacancy introduction into Na3PnS4, the solid solutions with WS42- introduction are explored. The influence of the substitution with WS42- for PS43- and SbS43-, respectively, is monitored using a combination of X-ray diffraction, Raman and impedance spectroscopy. With increasing vacancy concentration improvements resulting in a very high ionic conductivity of 13 ± 3 mS·cm-1 for Na2.9P0.9W0.1S4 and 41 ± 8 mS·cm-1 for Na2.9Sb0.9W0.1S4 can be observed. This work acts as a stepping-stone towards further engineering of ionic conductors using vacancy-injection via aliovalent substituents.

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