Full-section otolith microtexture imaged by local-probe X-ray diffraction

2018 ◽  
Vol 51 (4) ◽  
pp. 1182-1196 ◽  
Author(s):  
Phil K. Cook ◽  
Cristian Mocuta ◽  
Élise Dufour ◽  
Marie-Angélique Languille ◽  
Loïc Bertrand
Keyword(s):  
A Priori ◽  
Diffraction Method ◽  
Time Frame ◽  
Climatic Conditions ◽  
Structure Characterization ◽  
Fish Stock ◽  
Stock Management ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fish Otoliths

An optimized synchrotron-based X-ray diffraction method is described for the direct and efficient measurement of crystallite phase and orientation at micrometre resolution across textured polycrystalline samples of millimetre size (high scale dynamics) within a reasonable time frame. The method is demonstrated by application to biomineral fish otoliths. Otoliths are calcium carbonate accretions formed in the inner ears of vertebrates. Fish otoliths are essential biological archives, providing information for individual age estimation, the study of population dynamics and fish stock management, as well as past environmental and climatic conditions from archaeological specimens. Here, X-ray diffraction mapping is discussed as a means of describing the mineralogical structure and microtexture of otoliths. Texture maps could be generated with a fewa priorihypotheses on the aragonitic system. Full-section imaging allows quantitative intercomparison of crystal orientation coupled to microstructural description, across the zones of the otoliths that represent distinctive mineral organization. It reveals the extents of these regions and their internal textural structure. Characterization of structural and textural correlations across whole images is therefore proposed as a complementary approach to investigate and validate the local in-depth nanometre-scale study of biominerals. The estimation of crystallite size and orientational distribution points to diffracting domains intermediate in size between the otolith nanogranules and the crystalline units, in agreement with recently reported results.

scholarly journals Study of Corrosion Resistance and Degradation Mechanisms in LiTiO2-Li2TiO3 Ceramic

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 753
Author(s):  
Dmitriy Shlimas ◽  
Artem L. Kozlovskiy ◽  
Maxim Zdorovets
Keyword(s):  
Degradation Mechanism ◽  
Diffraction Method ◽  
Large Mass ◽  
Time Frame ◽  
X Ray Diffraction ◽  
Acidic Media ◽  
X Ray ◽  
Mass Losses ◽  
The Stability ◽  
Thermal Sintering

The interest in lithium-containing ceramics is due to their huge potential as blanket materials for thermonuclear reactors for the accumulation of tritium. However, an important factor in their use is the preservation of the stability of their strength and structural properties when under the influence of external factors that determine the time frame of their operation. This paper presents the results of a study that investigated the influence of the LiTiO2 phase on the increasing resistance to degradation and corrosion of Li2TiO3 ceramic when exposed to aggressive acidic media. Using the X-ray diffraction method, it was found that an increase in the concentration of LiClO4·3H2O during synthesis leads to the formation of a cubic LiTiO2 phase in the structure as a result of thermal sintering of the samples. During corrosion tests, it was found that the presence of the LiTiO2 phase leads to a decrease in the degradation rate in acidic media by 20–70%, depending on the concentration of the phase. At the same time, and in contrast to the samples of Li2TiO3 ceramics, for which the mechanisms of degradation during a long stay in aggressive media are accompanied by large mass losses, for the samples containing the LiTiO2 phase, the main degradation mechanism is pitting corrosion with the formation of pitting inclusions.

Structure Characterization of Ni/Al2O3 Composite Coatings Prepared by Electrodeposition

2010 ◽  
Vol 163 ◽  
pp. 64-67 ◽  
Author(s):  
Anna Góral ◽  
E. Bełtowska-Lehman ◽  
P. Indyka
Keyword(s):  
Composite Coatings ◽  
Diffraction Method ◽  
Rotating Disk ◽  
Rotating Disk Electrode ◽  
Structure Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pole Figures ◽  
Steel Substrates

In the present study, the electrodeposition of composites consisted of metal matrix (nickel) and inert particles (hard nano-sized Al2O3 oxide) has been carried out in a Watt’s type bath of pH 4, at room temperature in a system with the steel rotating disk electrode. The influence of dispersed Al2O3 powder on structure characteristics (morphology, phase composition, texture, residual stresses) of Ni/Al2O3 coatings has been investigated. The crystallographic texture of Ni and Ni/Al2O3 coatings deposited on the steel substrates was analyzed by XRD technique based on the back-reflection pole figures. The “sin2ψ” X-ray diffraction method was used to determine the residual stress as a function of X-ray penetration depth. The influence of Al2O3 particles on the value of the Ni coating microhardness was also analyzed.

Alkali Metals salts of a Tetracyanopyridine (TCPy) Derivative: Structure Characterization and Luminescence Properties

CrystEngComm ◽  
2021 ◽  
Author(s):  
Sergey Chunikhin ◽  
Oleg V Ershov ◽  
Aleksandr V. Yatsenko ◽  
Viktor Tafeenko ◽  
Natalia Evgenievna Dmitrieva ◽  
...  
Keyword(s):  
Solid State ◽  
Single Crystal ◽  
Alkali Metals ◽  
Diffraction Method ◽  
Structure Characterization ◽  
Luminescence Properties ◽  
X Ray Diffraction ◽  
Sodium Potassium ◽  
X Ray

Five new salts of 3,4-dicyano-2-(dicyanomethylene)-5-methyl-6-phenyl-2H-pyridin-1-ide anion (TCPy−) with lithium, sodium, potassium, rubidium and cesium cations were synthesized and structurally characterized by the single-crystal X-ray diffraction method. Solid state photoluminescence characteristics...

scholarly journals Growth of sillenite Bi12FeO20 single crystals: structural, thermal, optical, photocatalytic features and first principle calculations

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Durga Sankar Vavilapalli ◽  
Ambrose A. Melvin ◽  
F. Bellarmine ◽  
Ramanjaneyulu Mannam ◽  
Srihari Velaga ◽  
...  
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Photoelectron Spectroscopy ◽  
Diffraction Method ◽  
Lattice Parameter ◽  
First Principle ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Principle Calculations ◽  
Photodegradation Efficiency

AbstractIdeal sillenite type Bi12FeO20 (BFO) micron sized single crystals have been successfully grown via inexpensive hydrothermal method. The refined single crystal X-ray diffraction data reveals cubic Bi12FeO20 structure with single crystal parameters. Occurrence of rare Fe4+ state is identified via X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS). The lattice parameter (a) and corresponding molar volume (Vm) of Bi12FeO20 have been measured in the temperature range of 30–700 °C by the X-ray diffraction method. The thermal expansion coefficient (α) 3.93 × 10–5 K−1 was calculated from the measured values of the parameters. Electronic structure and density of states are investigated by first principle calculations. Photoelectrochemical measurements on single crystals with bandgap of 2 eV reveal significant photo response. The photoactivity of as grown crystals were further investigated by degrading organic effluents such as Methylene blue (MB) and Congo red (CR) under natural sunlight. BFO showed photodegradation efficiency about 74.23% and 32.10% for degrading MB and CR respectively. Interesting morphology and microstructure of pointed spearhead like BFO crystals provide a new insight in designing and synthesizing multifunctional single crystals.

Study of the quality of GaAs thin film on Si substrate by X-ray diffraction method

1990 ◽  
Vol 7 (7) ◽  
pp. 308-311
Author(s):  
Li Chaorong ◽  
Mai Zhenhong ◽  
Cui Shufan ◽  
Zhou Junming ◽  
Yutian Wang
Keyword(s):  
Thin Film ◽  
Diffraction Method ◽  
X Ray Diffraction ◽  
Si Substrate ◽  
X Ray

A New X‐Ray Diffraction Method for Studying Imperfections of Crystal Structure in Polycrystalline Specimens

1951 ◽  
Vol 22 (5) ◽  
pp. 665-672 ◽  
Author(s):  
Alfred J. Reis ◽  
Jerome J. Slade ◽  
Sigmund Weissmann
Keyword(s):  
Crystal Structure ◽  
Diffraction Method ◽  
X Ray Diffraction ◽  
X Ray

Crystal structure characterization and electronic structure of a rare-earth-containing Zintl phase in the Yb–Al–Sb family: Yb3AlSb3

2021 ◽  
Vol 77 (6) ◽  
Author(s):  
Rongqing Shang ◽  
An T. Nguyen ◽  
Allan He ◽  
Susan M. Kauzlarich
Keyword(s):  
Crystal Structure ◽  
Electronic Structure ◽  
Rare Earth ◽  
Electronic Structure Calculations ◽  
Structure Characterization ◽  
Charge Balance ◽  
X Ray Diffraction ◽  
Zintl Phase ◽  
X Ray ◽  
Structure Calculations

A rare-earth-containing compound, ytterbium aluminium antimonide, Yb3AlSb3 (Ca3AlAs3-type structure), has been successfully synthesized within the Yb–Al–Sb system through flux methods. According to the Zintl formalism, this structure is nominally made up of (Yb2+)3[(Al1−)(1b – Sb2−)2(2b – Sb1−)], where 1b and 2b indicate 1-bonded and 2-bonded, respectively, and Al is treated as part of the covalent anionic network. The crystal structure features infinite corner-sharing AlSb4 tetrahedra, [AlSb2Sb2/2]6−, with Yb2+ cations residing between the tetrahedra to provide charge balance. Herein, the synthetic conditions, the crystal structure determined from single-crystal X-ray diffraction data, and electronic structure calculations are reported.

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