Size dependent content of structural vacancies within TiO nanoparticles: Quantum-chemical DFTB study

Popov, I. S.; Enyashin, Andrey N.; Rempel, А. А.

doi:10.1016/j.spmi.2017.11.031

Cited by 10 publications

(2 citation statements)

References 31 publications

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“…This suggests a different mechanism of variation in the composition and vacancy concentration compared with the microcrystalline state under atmospheric pressure. Note also that the nanostate features smaller lattice period values compared with the microcrystalline state, which agrees with the predictions of theoretical calculations [30].…”

Section: Resultssupporting

confidence: 90%

Effect of high pressures and high temperatures on the structure of nanostructured titanium monoxide

Валеева¹,

Kostenko²,

Pfitzner³

et al. 2018

Nanosystems: Phys. Chem. Math.

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The structure of nanostructured titanium monoxide TiO 0.98 containing structural vacancies in two sublattices simultaneously has been modified via thermobaric annealing. Analysis of the experimental data on thermobaric synthesis of nanostructured TiO 0.98 with cubic B1 type structure at temperatures 573-2273 K and pressure 6 GPa revealed that a transition from the cubic B1 (sp. gr. F m3m) phase to the trigonal Ti 2 O 3 (sp. gr. R3c) phase takes place in the nanostructured monoxide as a result of high pressures and high temperatures. The first-principle calculations of the cohesive energy and electronic structure show that the trigonal phase with space group R3c is energetically favorable compared to the cubic phase of the same composition TiO 3/2 and the orthorhombic ordered Ti 2 O 3 (sp. gr. Immm) phase.

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Section: Resultssupporting

confidence: 90%

Effect of high pressures and high temperatures on the structure of nanostructured titanium monoxide

Валеева¹,

Kostenko²,

Pfitzner³

et al. 2018

Nanosystems: Phys. Chem. Math.

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“…Titanium monoxide materials TiO x , in bulk, low-dimensional, and nanostructured forms, are the subject of advanced investigations revealing their unique electronic, thermoelectric, optical and antibacterial properties [3][4][5][6][7][8][9]. Nonstoichiometric nature of TiO has generated a paradigm that at ambient conditions, bulk titanium monoxide is stable only if high concentration of structural vacancies is available [10]. Furthermore, this compound is a convenient model object for studying the behavior of point defects at high pressures [11][12][13][14].…”

Section: Introductionmentioning

confidence: 99%

Stability of vacancy-free crystalline phases of titanium monoxide at high pressure and temperature

Chtchelkatchev

Ryltsev

Magnitskaya

et al. 2020

Eur. Phys. J. Spec. Top.

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There have existed for a long time a paradigm that TiO phases at ambient conditions are stable only if structural vacancies are available. Using an evolutionary algorithm, we perform an ab initio search of possible zero-temperature polymorphs of TiO in wide pressure interval. We obtain the Gibbs energy of the competing phases taking into account entropy via quasiharmonic approximation and build the pressure-temperature diagram of the system. We reveal that two vacancy-free hexagonal phases are the most stable at relatively low temperatures in a wide range of pressures. The transition between these phases takes place at 28 GPa. Only above 1290 K at ambient pressure the phases with vacancies (B1-derived) become stable. In particular, the high-pressure hexagonal phase is shown to have unusual electronic properties, with a pronounced pseudo-gap in the electronic spectrum. The comparison of DFT-GGA and GW calculations demonstrates that the account for many-body corrections significantly changes the electronic spectrum near the Fermi energy.

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Main concepts and applications of DFTB approach

Berdimurodov

Guo

Kholikov

et al. 2023

Chemical Reactivity

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Size dependent content of structural vacancies within TiO nanoparticles: Quantum-chemical DFTB study

Cited by 10 publications

References 31 publications

Effect of high pressures and high temperatures on the structure of nanostructured titanium monoxide

Effect of high pressures and high temperatures on the structure of nanostructured titanium monoxide

Stability of vacancy-free crystalline phases of titanium monoxide at high pressure and temperature

Main concepts and applications of DFTB approach

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