X-ray emission spectra and quantum chemical calculations of electronic structure of vanadium oxides

Gubanov, V. A.; Lazukova, N. I.; Kurmaev, E.Z.

doi:10.1016/0022-4596(76)90143-2

Cited by 12 publications

(2 citation statements)

References 16 publications

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“…Oxidation states V +2 , V +3 , V +4 , and V +5 are all rather common for vanadium in different substances including oxide compounds. [23][24][25][26] The region of the V-O phase diagram between V 2 O 3 and V 2 O 5 contains two series of phases with mixed vanadium oxidation states restricting VO 2 : Magneli phases with general formula V n O 2n−1 (3 ⩽ n ⩽ 9) which are oxygen-deficient in relation to VO 2 , and oxygen-excessive Wadsley phases (V n O 2n+1 )-V 6 O 13 27 and V 3 O 7 . 28 Many of these substances demonstrate MIT at different temperatures, leading to this region's great interest.…”

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confidence: 99%

Editors’ Choice—Equilibrium Boundaries of VO₂ Phase Stability: Determination by Solid Electrolyte EMF Measurements and Effect on Optical Changes during Metal-Insulator Transition

Sudarikov,

Amelichev,

Kaul

2023

J. Electrochem. Soc.

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Vanadium dioxide is widely known for its metal-insulator transition (MIT), in which drastic changes in resistivity and IR-transparency occur. This makes VO2 thin films promising materials for high-frequency optoelectronic devices. To get the most MIT sharpness, thin films should not contain impurities of hyper-oxygen or hypo-oxygen phases arising during VO2 synthesis. To ascertain the conditions of single-phase VO2 existence, the equilibrium boundaries of VO2 with neighboring phases were determined using the electromotive force method (EMF) with a solid electrolyte ZrO2(Y2O3). Our data for the high-oxygen boundary of VO2 existence in equilibrium with the V6O13 phase agree with the only data known in the literature. We established that VO2 is, in equilibrium with the V9O17 phase at the low-oxygen boundary, which forms V8O15 under further reduction. The temperature of the peritectoid decomposition of V9O17 is established, and the corresponding corrections to the phase diagram of the vanadium-oxygen system are introduced. The Gibbs energies for V9O17, V8O15, and V6O13 formation reactions are calculated. It is also shown that the IR reflectance of VO2 films brought to equilibrium at the high-oxygen boundary is much greater than that of films equilibrated at the low-oxygen boundary.

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Editors’ Choice—Equilibrium Boundaries of VO₂ Phase Stability: Determination by Solid Electrolyte EMF Measurements and Effect on Optical Changes during Metal-Insulator Transition

Sudarikov,

Amelichev,

Kaul

2023

J. Electrochem. Soc.

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“…The delocalization of electrons leads to the appearance of nonzero The theoretical diagram of the cluster energy levels can be directly compared with the emission spectra produced by the transitions of valence electrons to the vacancies of inner shells [7]. Figure 3 shows experimental K O , L, spectra for vanadium, K , spectrum of oxygen and the corresponding intensities calculated.…”

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confidence: 99%

Electric field gradient calculation in V₂O₅

Lazukova¹,

Gubanov²,

Pletnev³

1975

Int J of Quantum Chemistry

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AbstractsThe electric field gradient at the "V nucleus in VzO, has been calculated by the .Mulliken-Wolfsberg-Helmholtz method. In contrast to the results obtained from crystal field theory, covalency effects in the MO method are shown to give rise to a valence contribution comparable with the lattice contribution. The total electric field gradient correlates with NMR experiments and confirms the adequacy of the method of calculation used.Le gradient du champ Clectrique au noyau 51V dans V,Os a CtC calculC par la mtthode de Mulliken-Wolfsberg-Helmholtz. Contrairement aux rksultats obtenus de la thCorie du champ cristallin les effets de covalence dans la mCthode MO donnent une contribution de valence comparable 2 celle du rCseau. Le gradient total du champ Clectrique est en bon accord avec les risultats des expkriences RMN ce qui confirme l'aptitude de la mCthode employ Ce. The NMR spectroscopy is known to be the effective method of studying electric and magnetic interactions and the symmetry of the crystal surrounding of a resonating nucleus in a solid. However, the values of chemical shift and nuclear quadrupole interaction tensors obtained from the wide line NMR experiments have no direct relations with peculiarities of the electronic structure of the compound under investigation. Such a dependence can be derived only from the results of theoretical calculations.In the present paper, using vanadium pentoxide as an example, the possibility of applying semiempirical molecular orbital methods to the calculations of the electric field gradient (EFG) at the vanadium nucleus in solid is investigated.The NMR spectra of polycrystalline V205 were obtained using the NMR spectrometer BS-477 (modified for recording wide line spectra) in the frequency 69 1

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X‐ray K emission spectra of vanadium in various oxidation states

Yasuda¹,

Kakiyama²

1978

X-Ray Spectrometry

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The Ka,, 2 , KO1, 3 , KO,, and KP" emission spectra of vanadium in the element and several V(III), V(IV), and V(V) compounds have been measured with a two-crystal X-ray spectrometer. The Kal and KP1,3 peaks shift slightly to lower energies with increasing the oxidation state of vanadium atom and the K& peak shifts to higher energies with it. An approximately linear relationship between Kal width and Kal / K a 2 intensity ratio can be used for identification of vanadium oxidation state.

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X-ray emission spectra and quantum chemical calculations of electronic structure of vanadium oxides

Cited by 12 publications

References 16 publications

Editors’ Choice—Equilibrium Boundaries of VO₂ Phase Stability: Determination by Solid Electrolyte EMF Measurements and Effect on Optical Changes during Metal-Insulator Transition

Editors’ Choice—Equilibrium Boundaries of VO₂ Phase Stability: Determination by Solid Electrolyte EMF Measurements and Effect on Optical Changes during Metal-Insulator Transition

Electric field gradient calculation in V₂O₅

X‐ray K emission spectra of vanadium in various oxidation states

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X-ray emission spectra and quantum chemical calculations of electronic structure of vanadium oxides

Cited by 12 publications

References 16 publications

Editors’ Choice—Equilibrium Boundaries of VO2 Phase Stability: Determination by Solid Electrolyte EMF Measurements and Effect on Optical Changes during Metal-Insulator Transition

Editors’ Choice—Equilibrium Boundaries of VO2 Phase Stability: Determination by Solid Electrolyte EMF Measurements and Effect on Optical Changes during Metal-Insulator Transition

Electric field gradient calculation in V2O5

X‐ray K emission spectra of vanadium in various oxidation states

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Editors’ Choice—Equilibrium Boundaries of VO₂ Phase Stability: Determination by Solid Electrolyte EMF Measurements and Effect on Optical Changes during Metal-Insulator Transition

Editors’ Choice—Equilibrium Boundaries of VO₂ Phase Stability: Determination by Solid Electrolyte EMF Measurements and Effect on Optical Changes during Metal-Insulator Transition

Electric field gradient calculation in V₂O₅