Identification of Heterogeneous State and Trajectories of Interstitials in the Titanium-Oxygen System Using Precise Diffusion Experiment

Выходец, В. Б.; Куренных, Т. Е.; Fishman, Anatoly Yakovlevich

doi:10.4028/www.scientific.net/ddf.143-147.79

Cited by 5 publications

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“…First-principles calculations suggest anisotropic migration of carbon in the tetragonal lattices of anatase ( c / a = 2.51) and rutile TiO 2 ( c / a = 0.64). , Therefore, substrate grain-dependent material transport in TiO 2 , which brings about substrate texture-dependent conversion time scales of the anodic TiO 2 at a given temperature, may be responsible for the substrate grain-dependent chemical compositions of TiOC 650 and TiOC 750 . When oxygen and carbon start to diffuse into the Ti substrate, the grain-dependent orientation of the hexagonal Ti lattice ( c / a = 1.58) is likely to determine the diffusion kinetics , and therewith not only the fractions of C and O that remain in the TiO x C y phase adjacent to the Ti substrate but also the thickness of the TiO x C y layer. In addition, the substrate grain boundaries can affect the conversion of the anodic TiO 2 .…”

Section: Discussionmentioning

confidence: 99%

Substrate Grain-Dependent Chemistry of Carburized Planar Anodic TiO₂ on Polycrystalline Ti

et al. 2017

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Mixtures or composites of titania and carbon have gained considerable research interest as innovative catalyst supports for low-and intermediate-temperature proton-exchange membrane fuel cells. For applications in electro-catalysis, variations in the local physicochemical properties of the employed materials can have significant effects on their behavior as catalyst supports. To assess microscopic hetero-geneities in composition, structure, and morphology, a microscopic multitechnique approach is required. In this work, compact anodic TiO2 films on planar polycrystalline Ti substrates are converted into carbon/titania composites or multiphase titanium oxycarbides through carbothermal treatment in an acetylene/argon atmosphere in a flow reactor. The local chemical composition, structure, and morphology of the converted films are studied with scanning photoelectron microscopy, micro-Raman spectroscopy, and scanning electron microscopy and are related with the crystallographic orientations of the Ti substrate grains by means of electron backscatter diffraction. Different annealing temperatures, ranging from 550 to 850 degrees C, are found to yield different substrate grain-dependent chemical compositions, structures, and morphologies. The present study reveals individual time scales for the carbothermal conversion and subsequent surface re-oxidation on substrate grains of a given orientation. Furthermore, it demonstrates the power of a microscopic multitechnique approach for studying polycrystalline heterogeneous materials for electrocatalytic applications

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Section: Discussionmentioning

confidence: 99%

Substrate Grain-Dependent Chemistry of Carburized Planar Anodic TiO₂ on Polycrystalline Ti

et al. 2017

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“…Increasing the oxygen content in titanium forms ordered layered-oxide phases, which rely on the diffusion of oxygen into alternating basal planes to form. [4][5][6][7] These oxides are brittle and facilitate further penetration of oxygen into titanium. One could consider different possible approaches to solve this problem: designing titanium alloys to reduce the high oxygen solubility (33 at.…”

Section: Introductionmentioning

confidence: 99%

Solute effect on oxygen diffusion in α-titanium

Trinkle²

2013

Journal of Applied Physics

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We calculate first-principles interaction energies between substitutional solutes and oxygen interstitials in a-titanium and predict the effect of solutes on oxygen diffusion from those interactions. Interaction between 45 solutes across the periodic table and three oxygen interstitial sites are calculated with density-functional theory. The interaction energies show distinct trends across the periodic table corresponding to both atomic radii and the period. Changes in diffusion barrier due to solutes are modeled with the kinetically resolved activation barrier approximation. Solute effects at infinite dilution are numerically calculated and show both accelerated and reduced oxygen diffusivity. V

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Titanium Oxycarbides: Formation, Properties and Application in Electrocatalysis

Kunze‐Liebhäuser¹,

Rüdiger²

2019

Reference Module in Chemistry, Molecular Sciences and Chemical Engineering

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Identification of Heterogeneous State and Trajectories of Interstitials in the Titanium-Oxygen System Using Precise Diffusion Experiment

Cited by 5 publications

References 0 publications

Substrate Grain-Dependent Chemistry of Carburized Planar Anodic TiO₂ on Polycrystalline Ti

Substrate Grain-Dependent Chemistry of Carburized Planar Anodic TiO₂ on Polycrystalline Ti

Solute effect on oxygen diffusion in α-titanium

Titanium Oxycarbides: Formation, Properties and Application in Electrocatalysis

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Identification of Heterogeneous State and Trajectories of Interstitials in the Titanium-Oxygen System Using Precise Diffusion Experiment

Cited by 5 publications

References 0 publications

Substrate Grain-Dependent Chemistry of Carburized Planar Anodic TiO2 on Polycrystalline Ti

Substrate Grain-Dependent Chemistry of Carburized Planar Anodic TiO2 on Polycrystalline Ti

Solute effect on oxygen diffusion in α-titanium

Titanium Oxycarbides: Formation, Properties and Application in Electrocatalysis

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Product

Resources

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Substrate Grain-Dependent Chemistry of Carburized Planar Anodic TiO₂ on Polycrystalline Ti

Substrate Grain-Dependent Chemistry of Carburized Planar Anodic TiO₂ on Polycrystalline Ti