Центральная Научная Библиотека УрО РАН

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   A 10


    A Novel Complex Cobalt Gallium Oxide Ca2Co0.8Ga1.2O4.8: Synthesis and High-Temperature Electron Transport Properties [] = A Novel Complex Cobalt Gallium Oxide Ca2Co0.8Ga1.2O4.8: Synthesis and High-Temperature Electron Transport Properties / S. Ya. Istomin, E. V. Antipov, G. Svensson, J. P. Attfield, V. L. Kozhevnikov, I. A. Leonidov, M. V. Patrakeev, E. B. Mitberg // Journal of Solid State Chemistry. - 2002. - V. 167, N 1. - С. 196-202 . - ISSN 0022-4596

ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Кл.слова (ненормированные):
СЛОЖНЫЕ ОКСИДЫ -- ОКСИДЫ СЛОЖНЫЕ -- ЭЛЕКТРОНЫ -- ДИФРАКЦИЯ -- ЭЛЕКТРОННЫЕ СВОЙСТВА -- СВОЙСТВА ЭЛЕКТРОННЫЕ -- ПОРОШКИ -- ОКСИД КОБАЛЬТА -- ОКСИД ГАЛЛИЯ -- СИНТЕЗ -- ПРОВОДИМОСТЬ -- ВЫСОКОТЕМПЕРАТУРНЫЕ СВОЙСТВА -- СВОЙСТВА ВЫСОКОТЕМПЕРАТУРНЫЕ -- ЭЛЕКТРИЧЕСКИЕ СВОЙСТВА -- СВОЙСТВА ЭЛЕКТРИЧЕСКИЕ -- Co -- Ga -- Ga -- КОБАЛЬТ -- ГАЛЛИЙ -- РЕНТГЕНОВСКАЯ ДИФРАКЦИЯ
Аннотация: A new complex oxide with the cation ratio Ca:Co:Ga = 2:0.8:1.2 has been synthesized in air at 1150oC. The cobalt atoms adopt oxidation states 2+ and 3+ in equal amounts giving an oxygen content corresponding to the composition Ca2Co0.8Ga1.2O4.8. It crystallizes in F-centered cubic structure with a = 15.0558 Angstrom. Conductivity measurements performed at high temperatures revealed that the temperature increase gives a charge disproportionation of Co3+ species resulting in a small concentration of Co4+ species and thus a small p-type conductivity in the oxide. A decrease of the oxygen pressure promotes oxygen depletion from the oxide and a deterioration of the conductivity. The electric properties are interpreted within a small polaron conduction mechanism. An unusually large mobility activation energy of 0.45 eV can be explained by a large spatial separation of cobalt cations in the structure

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   A 62


    Antioxidants in carbon-bearing refractories / V. G. Bamburov, O. V. Sivtsova, V. P. Semyannikov, V. A. Kiselev // Refractories and Industrial Ceramics. - 2000. - Vol. 41, № 2. - P33-36 : il. - Bibliogr. : p. 36 (6 ref.)

ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Кл.слова (ненормированные):
АНТИОКСИДАНТЫ -- ТУГОПЛАВКИЕ КАРБИДЫ
Аннотация: A study of boron-bcaring additives to periclase-carbon refractories is described. The special features of their oxidation and phase formation in heating ofpericlase-carbon compositions are investigated. It is shown that some of them can be used successfully as an antioxidant component that improves the operational characteristics of periclase-carbon ceramics. It is shown that the imported antioxidant boron-2000 is analogous to amorphous-boron (95 - 85%) preparations, and the latter are recommended for the creation of domestic grades of thermally stable periclase-carbon refractories

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   B 22


    Band Structure of the Superconducting MgB2 Compound and Modeling of Related Ternary Systems / N. I. Medvedeva, J. E. Medvedeva, A. L. Ivanovskii, V. G. Zubkov, A. J. Freeman // JETP Letters. - 2001. - Vol. 73, № 7. - P. 336-340 : il. - Bibliogr. : p. 340 (12 ref.)

ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Кл.слова (ненормированные):
ДИБОРИД МАГНИЯ -- СВЕРХПРОВОДИМОСТЬ -- СТРУКТУРА ЭЛЕКТРОННАЯ
Аннотация: Band structure of a novel superconductor—magnesium diboride—is studied by the self-consistent FP-LMTO method. Density of states near the Fermi level of MgB2 and its electronic properties are governed by the metallike boron 2p orbitals in the planar network of boron atoms. The modification of the band structure of MgB2 upon doping the boron (with Be, C, N, and O substitutional impurities) and the magnesium (with Be, Ca, Li, and Na substitutional impurities) sublattices or upon the introduction of structural vacancies (boron nonstoichiomety) is analyzed. The electronic structures of MgB2 and hypothetical CaB2 are also studied as functions of pressure

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   B 22

    Bannikov, V. V.
    Band structure, elastic and magnetic properties, and stability of antiperovskites MCNi3 (M = Y-Ag) according to FLAPW-GGA calculations [Текст] / V. V. Bannikov, I. R. Shein, A. L. Ivanovski // Physics of the Solid State. - 2007. - Vol. 49, № 9. - С. 1704-1714. - Библиогр. : с. 1713 (41 назв.)

ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Кл.слова (ненормированные):
АНТИПЕРОВСКИТЫ -- КАРБИДЫ -- МЕЖАТОМНОЕ ВЗАИМОДЕЙСТВИЕ
Аннотация: Using the full-potential linearized augmented plane wave method (FLAPW) and the WIEN2k software package, calculations of the band structure and the elastic and magnetic properties of the ternary antiperovskite carbides MCNi3, where M = Y, Zr,..., Ag (overall, nine compounds) are performed and the features of interatomic interactions in them are considered. Stability of these antiperovskite compounds depending on the 4d metal is discussed based on the calculated energies of formation of MCNi3 from the corresponding elements (according to the formal reaction M + C + 3Ni - MCNi3), and the conclusion is drawn that the YCNi3, ZrCNi3, and PdCNi3 antiperovskites can be synthesized. The obtained results are compared with the available data on known isostructural nickel-based carbides (antiperovskites MgCNi3, ZnCNi3)

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   B 22

    Bannikov, V. V.
    Double Exchange in Cubic Crystals with Pairs of Exchange-Coupled Mixed-Valence 3d3 –3d4 Ions / V. V. Bannikov, V. Ya. Mitrofanov // Physics of the Solid State. - 2005. - Vol. 47, № 8. - P1532-1534 : il. - Bibliogr. : p. 1534 (6 ref.)

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Рубрики: ХИМИЧЕСКИЕ НАУКИ
Кл.слова (ненормированные):
НЕСТЕХИОМЕТРИЯ -- 3-D ИОНЫ -- KZnF3
Аннотация: Specifics of the exchange interaction in mixed-valence Cr2+–Cr3+ 3d-ion pairs in KZnF3 crystals are studied. It is shown that the double-exchange interaction can be significantly reduced by the low-symmetry crystal field created by a compensator. The features of the exchange interaction and optical absorption spectra are qualitatively analyzed

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   B 33

    Bazuev, G. V.
    Synthesis and magnetic properties of incommensurate phases A4CuMn2O9 (A = Ca, Sr) [] = Synthesis and magnetic properties of incommensurate phases A4CuMn2O9 (A = Ca, Sr) / G. V. Bazuev, V. N. Krasil'nikov, D. G. Kellerman // Journal of Alloys and Compounds. - 2003. - V. 352. - С. 190-196. - Bibliogr.: p. 195-196 (26 ref.) . - ISSN 0925-8388

ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Кл.слова (ненормированные):
CuO -- MnO2 -- CaMnO3 -- Ca4CuMn2O9 -- ТВЕРДОФАЗНЫЙ СИНТЕЗ -- СИНТЕЗ ТВЕРДОФАЗНЫЙ -- Sr4CuMn2O9 -- Ca4CuMn2O9 -- Cu -- Mn -- МЕДЬ -- МАРГАНЕЦ -- Ca -- Sr -- КАЛЬЦИЙ -- СТРОНЦИЙ -- СЛОЖНЫЕ ОКСИДЫ -- ОКСИДЫ СЛОЖНЫЕ -- МАГНИТНЫЕ СВОЙСТВА -- СВОЙСТВА МАГНИТНЫЕ -- КАРБОНАТЫ -- МАНГАНИТ КАЛЬЦИЯ
Аннотация: New complex oxides A4CuMn2O9 (A = Ca and Sr) belonging to the family of quasi-one-dimensional compounds have been obtained by solid-phase synthesis from Ca and Sr carbonates and oxides CuO and MnO2. It was established that both oxides are incommensurate and can be characterized by two sublattice with the same a, but different c (c1 and c2) parameters. Magnetic susceptibility measurement results were interpreted with allowance for exchange-bound dimers Mn(4+)-Mn(4+) and paramagnetic centers Cu(2+). Magnetic measurements revealed the presence of calcium manganate CaMnO3 in Ca4CuMn2O9

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   B 41

    Belova, N. S.
    PbS Nanoparticles: Synthesis and Size Determination by X-ray Diffraction / N. S. Belova, A. A. Rempel // Inorganic Materials. - 2004. - Vol. 40, № 1. - P. 3-10 : il. - Bibliogr. : p. 9-10 (31 ref.)

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Рубрики: ХИМИЧЕСКИЕ НАУКИ
Кл.слова (ненормированные):
СУЛЬФИД СВИНЦА -- НАНОЧАСТИЦЫ -- ДИФРАКЦИЯ РЕНТГЕНОВСКАЯ
Аннотация: PbS particles down to 60 nm in size are prepared by chemical precipitation from aqueous solutions. An x-ray diffraction procedure is described for determining the particle size and atomic structure. The PbS particles precipitating in the solution bulk are shown to be monocrystalline. Reducing the particle size of PbS from 300 to 60 nm increases the rms atomic displacements (by 30%) and lattice strain (by 0.1%) in the particles. The lattice parameter of PbS is found for the first time to increase with decreasing particle size

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   B 78

    Borukhovich, A. S.
    Spin-Polarized Transport and Submillimetric Microwave Spectroscopy of Solids / A. S. Borukhovich, N. A. Viglin, V. V. Osipov // Physics of the Solid State. - 2002. - Vol. 44, № 5. - P938-945 : il. - Bibliogr. : p. 945 (27 ref.)

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Рубрики: ХИМИЧЕСКИЕ НАУКИ
Кл.слова (ненормированные):
ФЕРРОМАГНЕТИКИ -- ПОЛУПРОВОДНИКИ
Аннотация: The problem of spin transport (spin transfer and localization in space by charge carriers) is considered from the standpoint of implementing this phenomenon in microelectronic devices based on novel physical principles. Experimental data are presented to confirm the possibility of creating extremely-high-frequency solid state microelectronic devices, operating in the millimetric and submillimetric wavelength range, which can be used as the main elements for spin informatics. These devices can be based on ferromagnetic semiconductor–nonmagnetic semiconductor junctions, the output parameters of which are controlled both by the transport current and by an external magnetic field

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   C 74


    Concentration Phase Transition near the StoichiometricComposition of Vanadium Monoxide VO1.00 / D. A. Davydov, S. Z. Nazarova, A. A. Valeeva, A. A. Rempel // Bulletin of the Russian Academy of Sciences: Physics. - 2008. - Vol. 72, № 8. - P.1090-1093 : il. - Bibliogr. : p. 1093 (16 ref.)

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Рубрики: ХИМИЧЕСКИЕ НАУКИ
Кл.слова (ненормированные):
ФАЗОВЫЙ ПЕРЕХОД -- СТЕХИОМЕТРИЯ -- МОНООКСИД ВАНАДИЯ
Аннотация: The concentration dependences of the magnetic susceptibility and lattice parameter of cubic vanadium monoxide have been measured in the composition range from VO0.81 to VO1.07. Near the stoichiometric composition VO1.00, the concentration dependences exhibit a stepwise increase in the specific magnetic susceptibility??(by approximately 0.7 X 10(-6) cm(3)/g) and lattice constant (by about 0.002 nm). These effects can be??related to the concentration phase transition, which occurs in vanadium monoxide with a change from a substoichiometric composition to superstoichiometric. At such a transition, along with a decrease in the concentration of oxygen vacancies, tetrahedrally coordinated vanadium interstitials are formed, as a result of which the??B1 structure changes to a more complex cubic phase structure with the same space group??Fm-3m

\\\\Expert2\\nbo\\Bulletin of the Russian Academy of Sciences Physics\\2008, V. 72, N 8, P. 1090-1093.pdf
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10.

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   C 75


    Considering the Polynuclear Complexesin the Ionic Equilibria of the Pb2+–H2O System / N. S. Kozhevnikova, S. I. Sadovnikov, A. A. Uritskaya, A. I. Gusev // Russian Journal of General Chemistry. - 2012. - Vol. 82, № 4. - P. 626-634 : il. - Bibliogr. : p. 634 (36 ref.)

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Рубрики: ХИМИЧЕСКИЕ НАУКИ
Кл.слова (ненормированные):
ГИДРОКСИД СВИНЦА -- ИОННОЕ РАВНОВЕСИЕ
Аннотация: Analysis of conditions of the lead hydroxide and sulfide formation in the Pb2+–H2O system was carried out with accounting for the formation of polynuclear hydroxo-complexes. This allows predicting a possibility of the lead hydroxide formation in the solution before the beginning of the synthesis of lead sulfide. The domains of the stable formation of Pb(OH)2 and PbS were calculated for the systems containing lead citrate complexes and hydroxo-complexes. The proposed calculation method can be used for the quantitative determination of the reaction mixture composition and development of the chemical deposition technology of lead chalcogenides in different morphological forms: nanocrystalline powders (hydrophobic sol), quantum dots, heterostructures of the core@shell type or films. The proposed calculation method is applicable to other chalcogenide systems containing metal ions forming mononuclear and polynuclear hydroxo-complexes

\\\\Expert2\\nbo\\Russian Journal of General Chemistry\\2012, V. 82, N 4, p. 626–634.pdf
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11.

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   D 26

    Davydov, D. A.
    DO3-Type Cubic Structure of Nonstoichiometric Vanadium Monoxide / D. A. Davydov, A. I. Gusev // JETP Letters. - 2010. - Vol. 91, № 6. - P286-291 : il. - Bibliogr. : p. 291 (19 ref.)

ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Кл.слова (ненормированные):
МОНООКСИД ВАНАДИЯ -- НЕСТЕХИОМЕТРИЯ
Аннотация: An X-ray diffraction study indicates that nonstoichiometric vanadium monoxide VOy ≡ VxOz (y = z/x) has a cubic structure of the DO3 type (space group Fm m), where vanadium atoms are not only at the 4(a) sites of the metal fcc sublattice, but also at the tetrahedral 8(c) sites. This circumstance fundamentally distinguishes monoxide VOy from strongly nonstoichiometric MXy compounds with the B1 structure and the same space group, where atoms M and X and structural vacancies and of the metal and nonmetal sublattices, respectively, are distributed over the 4(a) and 4(b) sites. The dependence of the filling factor q of the tetrahedral interstices by vanadium atoms on the relative content y of oxygen in VOy has been obtained. It has been shown that the composition of cubic vanadium monoxide should be represented as VOy ≡ VxOz ≡ Vx – 2q 1 – x + 2qOz 1 –z, taking into account the structure

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12.

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   S 98


    Disorder-order phase transformations and electrical resistivity of nonstoichiometric titanium carbide [Text] / V. N. Lipatnikov, L. V. Zueva, A. I. Gusev, A. Kottar // Physics of the Solid State. - 1998. - Vol. 40, № 7. - P1211-1218. - Bibliogr. : p. 1218 (30 ref.)

ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Кл.слова (ненормированные):
КАРБИД ТИТАНА -- НЕСТЕХИОМЕТРИЯ -- ФАЗОВЫЙ ПЕРЕХОД -- ЭЛЕКТРОСОПРОТИВЛЕНИЕ
Аннотация: Phase transformations of the disorder-order type in the homogeneity region of nonstoichiometric titanium carbide TiCy (0.5
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13.

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   D 63


    Dissolution of Monazite in Humic Solutions / E. V. Polyakov, V. L. Volkov, V. T. Surikov, L. A. Perelyaeva, G. P. Shveikin // Radiochemistry. - 2010. - Vol. 52, № 4. - P429-434 : il. - Bibliogr. : p. 434 (16 ref.)

ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Кл.слова (ненормированные):
МОНАЦИТ -- ГУМИНОВАЯ КИСЛОТА -- РАСТВОРЕНИЕ
Аннотация: Physicochemical analysis shows that prolonged contact (15 days) of monazite powder with solutions containing humic acids (HA) of various acidities leads to an increase by 1–2 orders of magnitude in the dissolution of heavy p, d, and f elements present in monazite. The concentration of the dissolved elements depends on the initial content of HA in solution and on pH. These factors should be taken into account when using inorganic phosphates as matrices for long-term storage of radioactive and toxic elements

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14.

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   E 27


    Effect of radiation defects on the electronic structure of zircon by X-ray photoelectron / Yu. V. Shchapova, S. L. Votyakov, M. V. Kuznetsov, A. L. Ivanovskii // Journal of Structural Chemistry. - 2010. - Vol. 51, № 4. - P657-662 : il. - Bibliogr. : p. 662 (12 ref.)

ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Кл.слова (ненормированные):
РЕНТГЕНОВСКАЯ ФОТОЭЛЕКТРОННАЯ СПЕКТРОСКОПИЯ -- ЦИРКОНИЙ -- ЦИРКОН
Аннотация: X-Ray photoelectron spectroscopy (XPS) is used to study the electronic structure of radiation damaged samples of ZrSiO4 zircon mineral at early and middle stages of its radiation destruction. The effects of radiation induced atomic disordering are found to be most distinctly manifested in the spectra of O1s states and to a smaller extent in the spectra of Si2p states, and also in the zircon valence band. Based on the quantum chemical calculation results the conclusion is drawn that the observed changes in XPS lines are caused by the formation of oxygen vacancy defects and an increase in the covalency of interatomic bonds near oxygen vacancies. For zircon samples with a low/moderate degree of radiation damage these changes reflect the initial stage of the polymerization of the ZrSiO4 structure due to the formation of Si–O–Si chain fragments

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15.

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   E 27


    Effect of sodium and potassium polyvanadates on aluminum-powder oxidation / V. G. Shevchenko, V. L. Volkov, V. I. Kononenko, G. S. Zakharova, I. A. Chupova // Fizika Goreniya i Vzryva. - 1996. - Vol. 32, № 4. - P. 91-94 : il. - Bibliogr. : p. 94 (5 ref.)

ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Кл.слова (ненормированные):
ПОЛИВАНАДАТ НАТРИЯ -- ПОЛИВАНАДАТ КАЛИЯ -- ПОРОШКИ АЛЮМИНИЕВЫЕ -- ОКИСЛЕНИЕ
Аннотация: The effect of polyvanadates and vanadium oxide bronzes of alkali metals on aluminum-powder ozidation has been studied by thermogravimetry and x-ray phase analysis. The macromechanism of promotion of aluminum oxidation in which the catalytically active component is melted Na2AlxV12031 has been established. It is shown that the intermediate product of vanadiumcontaining slag9 processing can be used as an activator

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16.

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   E 43


    Electron/hole and ion transport in La1-xSrxFeO3-delta [] / M. V. Patrakeev, J. A. Bahteeva, E. B. Mitberg, I. A. Leonidov, V. L. Kozhevnikov, K. R. Poeppelmeier // Journal of Solid State Chemistry. - 2003. - V. 172, N 1. - С. 219-231 . - ISSN 0022-4596

ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Кл.слова (ненормированные):
ЭЛЕКТРОННЫЕ ДЫРКИ -- ИОННЫЙ ПЕРЕНОС -- La1-xSrxFeO3-ДЕЛЬТА -- ФЕРРИТЫ ЛАНТАНОСТРОНЦИЕВЫЕ -- КИСЛОРОДНАЯ ПРОВОДИМОСТЬ -- ПРОВОДИМОСТЬ КИСЛОРОДНАЯ -- ЭЛЕКТРОННАЯ ПРОВОДИМОСТЬ -- ПРОВОДИМОСТЬ ЭЛЕКТРОННАЯ -- ЛАНТАН-СТРОНЦИЙ
Аннотация: The conductivity of the entire solid solution La1-xSrxFeO3-delta, where x = 0.2, 0.4, 0.5, 0.7 and 0.9, in the oxygen partial pressure range 10(-19)-0.5 atm and temperatures between 750°C and 950°C is reported. The partial contributions from different charge carriers and the energetic parameters governing transport of charged species reveal that the lanthanum-strontium ferrites can be characterized as mixed, ion-electron conductors in the low oxygen pressure/high oxygen deficiency limit. The partial contributions to conductivity from oxygen ions, electrons and holes increase with strontium content and attain maximal values at x = 0.5. Further increase in doping results in development of oxygen vacancy ordering phenomena and deterioration of conducting properties

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17.

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   E 43


    Electronic band structure of thorium hydrides: ThH2 and Th4H15 [Текст] / I. R. Shein, K. I. Shein, N. I. Medvedeva, A. L. Ivanovskii // Physica B: Condensed Matter (Amsterdam, Netherlands). - 2007. - Vol. 389, № 2. - С. 296-301. - Bibliogr. : p. 300-301 (27 ref.)

ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Кл.слова (ненормированные):
ГИДРИД ТОРИЯ -- ПЕРВОПРИНЦИПНЫЕ РАСЧЕТЫ -- ПЛОТНОСТЬ
Аннотация: First principle calculations were performed using full-potential LAPW method with generalized gradient approximation (FLAPWGGA) to understand the electronic properties of thorium hydride Th4H15 and compare with those for alpha-Th and ThH2. The equilibrium geometries, the electronic band structure, the total and partial densities of states for these materials are obtained and analyzed in comparison with the available experimental data. We found that the Th6d and Th5f states give comparable contributions to NðEFÞ in alpha-Th, whereas only one of them, namely the Th6d or Th 5f states determine the largest contribution in ThH2 and Th4H15, respectively. We estimated the average electron–phonon coupling constant l to be 0.38 and concluded that Th4H15 may be considered as a weak coupling superconductor

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18.

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   E 43


    Electronic Properties of New Ca(AlxSi1 – x)2 and Sr(GaxSi1 – x)2 Superconductors in Crystalline and Nanotubular States / I. R. Shein, V. V. Ivanovskaya, N. I. Medvedeva, A. L. Ivanovskii // JETP Letters. - 2002. - Vol. 76, № 3. - P. 189-193 : il. - Bibliogr. : p. 193 (19 ref.)

ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Кл.слова (ненормированные):
СВЕРХПРОВОДНИКИ -- НАНОТРУБКИ КАРБОНОВЫЕ -- SrGaSi -- CaAlSi
Аннотация: The band structure of new layered (AlB2 type) Ca(AlxSi1 – x)2 and Sr(GaxSi1 – x)2 superconductors is studied by the first-principle full-potential LMTO method. It has been shown that the superconducting properties of ternary silicides are due to the high density of (Ca,Sr)d states at the Fermi level, whereas the growth of TC in going from Sr(GaxSi1 – x)2 to Ca(AlxSi1 – x)2 is associated with the increase in phonon frequencies due to the decrease in atomic masses. Simulations are performed for the electronic properties of hypothetical (11,11) and (20,0) CaAlSi and SrGaSi nanotubes. In going from the crystalline to the nanotubular state, the silicide systems retain metal-like properties. The template and “film rolling” techniques can be used for obtaining silicide nanotubes

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19.

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   E 43


    Electronic structure and chemical bonding in K2V3O8 [Текст] / V. M. Zainullina, V. L. Volkov, N. V. Podvalnaya, A. L. Ivanovskii // Journal of Structural Chemistry. - 2005. - Vol. 46, № 2. - С. 340-342. - Библиогр. : с. 342 (14 назв.)

ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Кл.слова (ненормированные):
ПОЛИВАНАДАТ КАЛИЯ -- ИОННАЯ ПРОВОДИМОСТЬ
Аннотация: The calculations of the electronic structure of layered polyvanadate K2V3O8 were made employing the spinpolarized tight-binding LMTO method. Calculated magnetic moment for K4V6O16 compound phase equals 1.97 мB. V-O interactions were established to be dominating in the chemical bonding generation in this polyvanadate according to the estimated crystal orbital overlap population. The covalent bonds V(2)-V(2) in V(2)2O7 groups and electron density localization on vanadium atoms in isolated pyramids V(1)O were found.

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20.

Инвентарный номер: нет.

   E 43


    Electronic structure and chemical bonding in Sr4Nb17O26 / V. M. Zainullina, V. P. Zhukov, V. G. Zubkov, A. P. Tyutyunnik // Journal of Structural Chemistry. - 1998. - Vol. 39, № 5. - P627-635 : il. - Bibliogr. : p. 634-635 (15 ref.)

ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Кл.слова (ненормированные):
ОКСОНИОБАТ СТРОНЦИЯ -- МЕТОД ЛМТО
Аннотация: The electronic structure of oxoniobate Sr4Nb17026 is studied by the linear muffin-tin orbital (LMTO) method. It is shown that the high-energy conduction band consists of the Nb4d states and the hybridized valence band is formed by the Nb4d and 02p states. The band structure of this compound is characterized by superposition of the bands of the 2p states of perovskite oxygen atoms and the 4d states of monoxide niobium atoms. The degree of oxidation of the perovskite and monoxide niobium atoms is + 5 and + 2.56, respectively. Chemical bonding is analyzed using the electron localization function and model Hiickel calculations. The niobium-oxygen bond is shown to be the strongest. The Fermi level is localized in the vicinity of the bottom of the niobium antibonding state band, which explains the existence of Sr4-xNb17026 in the homogeneity region corresponding to 0 < x < 0.3

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21.

Инвентарный номер: нет.

   E 43


    Electronic Structure and Magnetic States of Crystalline and Fullerene-Like Forms of Nickel Dichloride NiCl2 / A. N. Enyashin, N. I. Medvedeva, Yu. E. Medvedeva, A. L. Ivanovskii // Physics of the Solid State. - 2005. - Vol. 47, № 3. - P527-530 : il. - Bibliogr. : p. 530 (12 ref.)

ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Кл.слова (ненормированные):
ДИХЛОРИД НИКЕЛЯ -- ФУЛЛЕРЕНЫ -- ФЕРРОМАГНЕТИКИ -- СТЕХИОМЕТРИЯ
Аннотация: The electronic structure and magnetic properties of the crystalline and fullerene-like forms of nickel dichloride NiC² are investigated in the framework of the local spin density functional theory. It is demonstrated that the band gap can be reproduced in the energy band spectrum of the NiCl² compound with inclusion of the magnetic ordering in the calculation of the band structure. The metamagnetic nature of the NiCl² dichloride (i.e., the transition from an antiferromagnetic phase to a ferromagnetic phase in a weak magnetic field) is explained in terms of a small difference (0.025 eV/cell) between the total energies of the ferromagnetic and antiferromagnetic phases. Polyhedral three-shell nanoparticles of the NiCl² compound exhibit magnetic properties (the magnetic moment of nickel lies in the range 2.0–2.3 µβ). For isostructural nanoparticles of the FeCl² dichloride, the magnetic moment of iron is larger and falls in the range 4.2–4.5 µβ, whereas nanoparticles of the CdCl² dichloride are found to be nonmagnetic. The results of analyzing the interatomic interactions indicate that the composition of fullerene-like nanoparticles of the dichlorides under investigation can deviate from the 1 : 2 stoichiometric composition

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22.

Инвентарный номер: нет.

   E 43


    Electronic structure and magnetism in BeO nanotubes induced by boron,carbon and nitrogen doping, and beryllium and oxygen vacancies insidetube walls / M. A. Gorbunova, I. R. Shein, Yu. N. Makurin, V. V. Ivanovskaya, V. S. Kijko, A. L. Ivanovskii // Physica E. - 2008. - Vol. 41. - P. 164-168 : il. - Bibliogr. : p. 168 (22 ref.)

ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Кл.слова (ненормированные):
МОНООКСИД БЕРИЛЛИЯ -- МАГНЕТИЗМ -- НАНОТРУБКИ -- НЕСТЕХИОМЕТРИЯ
Аннотация: We have performed ab initio calculations to systematically investigate electronic properties and magnetism of insulating non-magnetic beryllium monoxide nanotubes (BeO NTs) induced by nonmagnetic sp impurities: boron, carbon and nitrogen, as well as by nanotube wall defects: Be or??O vacancies.We found that in the presence of these sp impurities, which replace oxygen atoms, the nonmagnetic BeO NTs transform into magnetic semiconductors, which acquire magnetization caused by spin splitting of (B, C, N) 2p states located in the forbidden gap of a BeO tube. The magnetic moments of the impurities vary from 0.65 to 1.60mB. It was also found that a beryllium vacancy leads to vacancyinduced magnetic moments (at about 0.6mB) arising on the nearest oxygen atoms and berylliumdeficient BeO nanotubes adopt half-metallic-like properties. On the contrary, when (B, C, N) dopants??substitute for Be atoms or in the presence of an oxygen vacancy, the non-magnetic state of the BeO??tubes is retained. The results obtained have been compared with theoretically predicted magnetization effects for doped and non-stoichiometric crystalline BeO

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23.

Инвентарный номер: нет.

   E 43


    Electronic structure and stability of thorium carbonitrides [Текст] / I. R. Shein, K. I. Shein, N. I. Medvedeva, A. L. Ivanovskii // Physica Status Solidi B: Basic Solid State Physics. - 2007. - Vol. 244, № 9. - С. 3198-3205. - Библиогр. : с. 3204 (29 назв.)

ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Кл.слова (ненормированные):
КАРБОНИТРИД ТОРИЯ -- ЭЛЕКТРОННАЯ СТРУКТУРА -- ПОЛУПРОВОДНИКИ
Аннотация: The electronic structure of the monoclinic (α-ThCN), hexagonal (β-ThCN) and cubic (ThCxN1–x) thorium carbonitrides is studied within the density-functional theory (DFT). We predict the metal conductivity for the solid solutions ThCxN1–x, but both α-ThCN and β-ThCN phases should be semiconductors with band gap 1.49 eV and 1.97 eV, respectively. Distinct from the 5f metal carbides and nitrides, both Th6d and Th5f states give comparable contributions to the density of states at the Fermi level in ThCxN1–x. The enthalpies of formation were estimated relative to the different reagents and the largest values were obtained for the reactions with simple reagents (α-Th, C, N)

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24.

Инвентарный номер: нет.

   E 58

    Enyashin, A. N.
    Atomic Defects of the Walls and the Electronic Structure of Molybdenum Disulfide Nanotubes / A. N. Enyashin, A. L. Ivanovskii // Semiconductors. - 2007. - Vol. 41, № 1. - P81-86 : il. - Bibliogr. : p. 86 (17 ref.)

ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Кл.слова (ненормированные):
ДИСУЛЬФИД МОЛИБДЕНА -- НАНОТРУБКИ
Аннотация: The method of the charge-density functional in the tight-binding approximation is used to study the effect of different types of wall atomic defects in the MoS2 nanotubes on their structural and electronic properties. It is shown that the atomic defects in the walls of the MoS2 nanotubes can be responsible for the semiconductor–metal transitions

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25.

Инвентарный номер: нет.

   E 58

    Enyashin, A. N.
    DNA-wrapped carbon nanotubes / A. N. Enyashin, S. Gemming, G. Seifert // Nanotechnology. - 2007. - V. 18, № 24. - P. 245702(10 pp.) : il. - Bibliogr. : p. 245702-10(47 ref.)

ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Кл.слова (ненормированные):
НАНОТРУБКИ УГЛЕРОДНЫЕ -- ДЕЗОКСИРИБОНУКЛЕИНОВАЯ КИСЛОТА
Аннотация: The stability and electronic properties of complexes of single-walled carbon nanotubes wrapped by homopolymeric single-stranded DNA molecules (CNT@DNA) are considered using a quantum mechanical density-functional tight-binding method (DFTB). A phenomenological model of the CNT@DNA formation energy depending on the nanotube radii is developed,which shows that the decoration of a CNT by a few DNA chains leads to a high water solubility of CNT@DNA. Pyrimidine-based DNAs are found to be more effective to wrap the CNTs than other DNAs. The densities of states of the CNT@DNA complexes are close to the superposition of those of the ‘free’ components with some additional states below the Fermi level. The band gap in a hybrid CNT@DNA system is determined by the competition between the Fermi levels of the ‘free’ DNA and CNT. In a few specific cases a considerable charge transfer from the DNA to the CNT was observed, combined with an additional gain in the CNT@DNA formation energy

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26.

Инвентарный номер: нет.

   E 58

    Enyashin, A. N.
    Mechanical and electronic properties of a C/BN nanocable under tensile deformation [] / A. N. Enyashin, A. L. Ivanovskii // Nanotechnology. - 2005. - V. 16, N 8. - С. 1304-1310. - Bibliogr.: p. 1309-1310 (48 ref.) . - ISSN 0957-4484

ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Кл.слова (ненормированные):
ЭЛЕКТРОННЫЕ СВОЙСТВА -- МЕХАНИЧЕСКИЕ СВОЙСТВА -- СВОЙСТВА ЭЛЕКТРОННЫЕ -- СВОЙСТВА МЕХАНИЧЕСКИЕ -- ДЕФОРМАЦИЯ -- НАПРЯЖЕНИЕ -- КАРБОНОВЫЕ НАНОТРУБКИ -- НАНОТРУБКИ КАРБОНОВЫЕ -- БОРОНИТРИДНЫЕ НАНОТРУБКИ -- НАНОТРУБКИ БОРОНИТРИДНЫЕ
Аннотация: Atomistic simulations are performed to investigate the structural, mechanical and electronic properties of a coaxial C/BN nanocable under axial elongation using molecular dynamics. Our results show that the mechanism of the breaking process essentially differs from those for initial single-walled carbon and BN nanotubes. The formation of a carbon as well as a -C-B-N-atomic chain connecting two cable fragments before fracture is obtained, and due to such bridges the cable can be stretched until complete rupture up to epsilon max~29% as compared with epsilon max~23% for a single-walled carbon nanotube. After breakage the opposite tips of cable fragments form different individual atomic morphologies and compositions and can have promising potential as electron emitters. The Young moduli of the C/BN cable and C-NT are comparable. An analysis of the electronic structure shows that during tensile deformation the C/BN cable retains the basic electronic characteristics (metallic-like
for the inner carbon nanotube and dielectric for the outer BN tube); however, the bandgap between the highest occupied N 2p and lowest unoccupied B 2p states decreases from 4.0 to 1.2 eV

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27.

Инвентарный номер: нет.

   E 58

    Enyashin, A. N.
    Modeling of the Atomic Structure and Thermal Stability of Titanium Monoxide Nanocrystals / A. N. Enyashin, A. L. Ivanovskii // Russian Journal of Inorganic Chemistry. - 2006. - Vol. 51, № 8. - P1302-1306 : il. - Bibliogr. : p. 1306 (12 ref.)

ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Кл.слова (ненормированные):
МОНООКСИД ТИТАНА -- НАНОКРИСТАЛЛЫ
Аннотация: The morphology, energy stability, and thermal behavior of the family of hypothetical extended nanocrystals (NCs) of titanium monoxide TiO are studied using the pair potential model. The increasing number of the walls enhances the stability of hollow TiO crystals having prismatic morphology. However, molecular-dynamic simulation shows that the regular structure of the NCs degrades even under the ambient conditions (300 K); most likely, extended nanostructures with the titanium monoxide stoichiometry (Ti/O = 1) will be manufactured in the form of amorphous nanofibers

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28.

Инвентарный номер: нет.

   E 58

    Enyashin, A. N.
    Nanosized allotropes of molybdenum disulfide / A. N. Enyashin, S. Gemming, G. Seifert // European Physical Journal Special Topics. - 2007. - Vol. 149. - P103-125 : il. - Bibliogr. : p. 125 (124 ref.)

ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Кл.слова (ненормированные):
ДИСУЛЬФИД МОЛИБДЕНА -- АЛЛОТРОПИЯ -- НАНОРАЗМЕРНЫЕ СТРУКТУРЫ
Аннотация: The present review provides an overview of the rich polymorphism encountered on different length scales within the very versatile material class of transition metal chalcogenides. On the mesoscopic to nanoscopic scale such compounds exhibit a wide variety of nanostructured allotropes with varying dimensionality and competing internal structure, such as nanorods, nanostripes, nanotubes, fullerene-like particles and fullerenes. On the atomistic scale, competing local atomic arrangements within one type of allotrope determine crucially the stability, the chemical potential, and the electronic properties. Thus, any modeling of such structures cannot be restricted to purely classical or quantummechanical approaches, but rather the development of classical models on the basis of electronic-structure calculations is required to fully account for all relevant nano- and meso-scale effects. The main part of this review is dedicated to the stability of such nanosystems in relation with the stable size regimes, with their electronic structure, and the derived analysis of the reactivity and application potential. The calculations explain, why the nano-scale properties of the MoS2 allotropes can be quite different from the bulk ones, and predict novel effects both within and in addition to the established applications of MoS2 compounds in catalysis, tribology, electronics and electrochemistry

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29.

Инвентарный номер: нет.

   E 58

    Enyashin, A. N.
    Simulation of the Structural and Thermal Properties of Tubular Nanocrystallites of Magnesium Oxide / A. N. Enyashin, G. Seifert, A. L. Ivanovskii // Physics of the Solid State. - 2006. - Vol. 48, № 4. - P801-805 : il. - Bibliogr. : p. 805 (34 ref.)

ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Кл.слова (ненормированные):
ОКСИД МАГНИЯ -- НАНОКРИСТАЛЛЫ
Аннотация: The morphology, energy stability, and thermal behavior of a family of MgO tubular nanocrystallites are investigated within the framework of the pair potential model. It is found that an increase in the number of layers forming walls of hollow MgO nanocrystallites of prismatic morphology results in an abrupt enhancement of their stability. It is concluded that the properties of these nanostructures should be stable over a wide range of crystallite sizes

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30.

Инвентарный номер: нет.

   E 58

    Enyashin, A. N.
    Structure and electronic characteristics of new graphyne-like fullerenes of boron nitride: quantum-chemical modelling / A. N. Enyashin, Yu. N. Makurin, A. L. Ivanovskii // Theoretical and Experimental Chemistry. - 2004. - Vol. 40, № 2. - P71-76 : il. - Bibliogr. : p. 75-76 (19 ref.)

ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Кл.слова (ненормированные):
ГРАФЕНОПОДОБНЫЕ ФУЛЛЕРЕНЫ -- НИТРИД БОРА -- КВАНТОВО-ХИМИЧЕСКОЕ МОДЕЛИРОВАНИЕ
Аннотация: Atomic models are proposed and quantum-chemical modelling is undertaken for hypothetical graphyne-like fullerenes of boron nitride. The electronic structure and interatomic interactions are discussed for the case of the B16N16 and B48N48 molecules. The proposed polyhedral boronnitrogen molecules, having stable dielectric characteristics and highly porous structure, may be of interest for the creation a family of new intercalated nanomaterials based on these nanoparticles

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