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

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.

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

Journal of Applied Crystallography ◽

10.1107/s1600576718008610 ◽

2018 ◽

Vol 51 (4) ◽

pp. 1182-1196 ◽

Cited By ~ 3

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.

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The Stability of CeNi3-Based Intermetallic Hydrides

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.365.24 ◽

2015 ◽

Vol 365 ◽

pp. 24-29

Author(s):

Stepan Alexandrovich Lushnikov ◽

Tatyana Victorovna Filippova

Keyword(s):

Phase Composition ◽

Low Temperatures ◽

Room Temperature ◽

Diffraction Method ◽

X Ray Diffraction ◽

Hydrogen Atoms ◽

X Ray ◽

The Stability ◽

Diffusion Of Hydrogen ◽

Hydride Phases

Hydrides of CeNi3 intermetallic compounds were synthesized with hydrogen at a pressure of up to 50 bars at room and low temperatures. Using the X-ray diffraction method gives phase composition and lattice parameters of the hydride samples. It was revealed that one set of the hydride samples was stable in air and at room temperature, while another set was very unstable at the same conditions and rapidly desorbed hydrogen. This diverse behaviour depends on the proportion of obtained hydride phases at low and room temperatures, coexisting in the samples. A possible explanation has been proposed based on the different diffusion of hydrogen atoms in ordered and disordered hydride phases, incorporated in the samples.

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Fractionation of polymethylene chains: An electron crystallographic investigation

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100145315 ◽

1986 ◽

Vol 44 ◽

pp. 794-795

Author(s):

Douglas L. Dorset

Keyword(s):

Cross Section ◽

Binary Systems ◽

Linear Chain ◽

Pure Component ◽

Organic Substrates ◽

Crystallographic Investigation ◽

X Ray Diffraction ◽

X Ray ◽

Molecular Sizes ◽

The Stability

A variety of linear chain materials exist as polydisperse systems which are difficultly purified. The stability of continuous binary solid solutions assume that the Gibbs free energy of the solution is lower than that of either crystal component, a condition which includes such factors as relative molecular sizes and shapes and perhaps the symmetry of the pure component crystal structures.Although extensive studies of n-alkane miscibility have been carried out via powder X-ray diffraction of bulk samples we have begun to examine binary systems as single crystals, taking advantage of the well-known enhanced scattering cross section of matter for electrons and also the favorable projection of a paraffin crystal structure posited by epitaxial crystallization of such samples on organic substrates such as benzoic acid.

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An X-ray diffraction method for semiquantitative mineralogical analysis of Chilean nitrate ore

Open-File Report ◽

10.3133/ofr94240 ◽

1994 ◽

Cited By ~ 3

Author(s):

J.C. Jackson ◽

G.E. Ericksen

Keyword(s):

Diffraction Method ◽

X Ray Diffraction ◽

Mineralogical Analysis ◽

X Ray

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A Superhydrophobic, Antibacterial, and Durable Surface of Poplar Wood

Nanomaterials ◽

10.3390/nano11081885 ◽

2021 ◽

Vol 11 (8) ◽

pp. 1885

Author(s):

Xinyu Wu ◽

Feng Yang ◽

Jian Gan ◽

Zhangqian Kong ◽

Yan Wu

Keyword(s):

Stearic Acid ◽

Antibacterial Properties ◽

Alkali Resistance ◽

Poplar Wood ◽

X Ray Diffraction ◽

X Ray ◽

Different Temperatures ◽

Acid And Alkali Resistance ◽

The Stability

The silver particles were grown in situ on the surface of wood by the silver mirror method and modified with stearic acid to acquire a surface with superhydrophobic and antibacterial properties. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray energy spectroscopy (XPS) were used to analyze the reaction mechanism of the modification process. Scanning electron microscopy (SEM) and contact angle tests were used to characterize the wettability and surface morphology. A coating with a micro rough structure was successfully constructed by the modification of stearic acid, which imparted superhydrophobicity and antibacterial activity to poplar wood. The stability tests were performed to discuss the stability of its hydrophobic performance. The results showed that it has good mechanical properties, acid and alkali resistance, and UV stability. The durability tests demonstrated that the coating has the function of water resistance and fouling resistance and can maintain the stability of its hydrophobic properties under different temperatures of heat treatment.

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Synthesis of Bis(Carboranyl)amides 1,1′-μ-(CH2NH(O)C(CH2)n-1,2-C2B10H11)2 (n = 0, 1) and Attempt of Synthesis of Gadolinium Bis(Dicarbollide)

Molecules ◽

10.3390/molecules26051321 ◽

2021 ◽

Vol 26 (5) ◽

pp. 1321

Author(s):

Yasunobu Asawa ◽

Aleksandra V. Arsent’eva ◽

Sergey A. Anufriev ◽

Alexei A. Anisimov ◽

Kyrill Yu. Suponitsky ◽

...

Keyword(s):

Molecular Structure ◽

Single Crystal ◽

Quantum Chemical Calculations ◽

Quantum Chemical ◽

X Ray Diffraction ◽

Stable Conformation ◽

Acyl Chlorides ◽

X Ray ◽

Cesium Fluoride ◽

The Stability

Bis(carboranyl)amides 1,1′-μ-(CH2NH(O)C(CH2)n-1,2-C2B10H11)2 (n = 0, 1) were prepared by the reactions of the corresponding carboranyl acyl chlorides with ethylenediamine. Crystal molecular structure of 1,1′-μ-(CH2NH(O)C-1,2-C2B10H11)2 was determined by single crystal X-ray diffraction. Treatment of bis(carboranyl)amides 1,1′-μ-(CH2NH(O)C(CH2)n-1,2-C2B10H11)2 with ammonium or cesium fluoride results in partial deboronation of the ortho-carborane cages to the nido-carborane ones with formation of [7,7′(8′)-μ-(CH2NH(O)C(CH2)n-7,8-C2B9H11)2]2−. The attempted reaction of [7,7′(8′)-μ-(CH2NH(O)CCH2-7,8-C2B9H11)2]2− with GdCl3 in 1,2-dimethoxy- ethane did not give the expected metallacarborane. The stability of different conformations of Gd-containing metallacarboranes has been estimated by quantum-chemical calculations using [3,3-μ-DME-3,3′-Gd(1,2-C2B9H11)2]− as a model. It was found that in the most stable conformation the CH groups of the dicarbollide ligands are in anti,anti-orientation with respect to the DME ligand, while any rotation of the dicarbollide ligand reduces the stability of the system. This makes it possible to rationalize the design of carborane ligands for the synthesis of gadolinium metallacarboranes on their base.

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

Scientific Reports ◽

10.1038/s41598-020-78598-3 ◽

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.

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Facile Organometallic Synthesis of Fe-Based Nanomaterials by Hot Injection Reaction

Nanomaterials ◽

10.3390/nano11051141 ◽

2021 ◽

Vol 11 (5) ◽

pp. 1141

Author(s):

Georgia Basina ◽

Hafsa Khurshid ◽

Nikolaos Tzitzios ◽

George Hadjipanayis ◽

Vasileios Tzitzios

Keyword(s):

Room Temperature ◽

Colloidal Particles ◽

Iron Pentacarbonyl ◽

Vibrating Sample Magnetometer ◽

X Ray Diffraction ◽

Organometallic Synthesis ◽

X Ray ◽

Transmission Electron ◽

Hot Injection ◽

The Stability

Fe-based colloids with a core/shell structure consisting of metallic iron and iron oxide were synthesized by a facile hot injection reaction of iron pentacarbonyl in a multi-surfactant mixture. The size of the colloidal particles was affected by the reaction temperature and the results demonstrated that their stability against complete oxidation related to their size. The crystal structure and the morphology were identified by powder X-ray diffraction and transmission electron microscopy, while the magnetic properties were studied at room temperature with a vibrating sample magnetometer. The injection temperature plays a very crucial role and higher temperatures enhance the stability and the resistance against oxidation. For the case of injection at 315 °C, the nanoparticles had around a 10 nm mean diameter and revealed 132 emu/g. Remarkably, a stable dispersion was created due to the colloids’ surface functionalization in a nonpolar solvent.

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Polydomain Structure of Epitaxial PbTiO3 films on MgO

MRS Proceedings ◽

10.1557/proc-493-111 ◽

1997 ◽

Vol 493 ◽

Cited By ~ 1

Author(s):

S. P. Alpay ◽

A. S. Prakash ◽

S. Aggarwal ◽

R. Ramesh ◽

A. L. Roytburd ◽

...

Keyword(s):

Domain Structure ◽

Pulsed Laser ◽

Laser Deposition ◽

X Ray Diffraction ◽

X Ray ◽

Theoretical Predictions ◽

The Stability ◽

Increasing Temperature ◽

Stable Domains ◽

Domain Stability

ABSTRACTA PbTiO3(001) film grown on MgO(001) by pulsed laser deposition is examined as an example to demonstrate the applications of the domain stability map for epitaxial perovskite films which shows regions of stable domains and fractions of domains in a polydomain structure. X-ray diffraction studies indicate that the film has a …c/a/c/a… domain structure in a temperature range of °C to 400°C with the fraction of c-domains decreasing with increasing temperature. These experimental results are in excellent agreement with theoretical predictions based on the stability map.

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