Библиотека института физики им. Л.В. Киренского СО РАН

Главная

Базы данных

Труды сотрудников ИФ СО РАН - результаты поиска

Вид поиска

Каталог книг и брошюр библиотеки ИФ СО РАН

Каталог журналов библиотеки ИФ СО РАН

Труды сотрудников ИФ СО РАН

Область поиска

в найденном

Найдено в других БД:

Каталог книг и брошюр библиотеки ИФ СО РАН (148)

Каталог журналов библиотеки ИФ СО РАН (35)

Формат представления найденных документов:
полный	информационный	краткий

Отсортировать найденные документы по:
автору	заглавию	году издания	типу документа

Поисковый запрос: (<.>K=chemistry<.>)

Общее количество найденных документов : 509
Показаны документы с 1 по 10

1-10 11-20 21-30 31-40 41-50 51-60

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Molokeev M. S., Bogdanov E. V., Misyul S. V., Tressaud A., Flerov I. N.
Заглавие : Crystal structure and phase transition mechanisms in CsFe2F6
Место публикации : J. Solid State Chem. - 2013. - Vol. 200. - P.157-164. - DOI 10.1016/j.jssc.2013.01.038
Аннотация: For the first time, structural phase transitions induced by the temperature were found in AxMxIIM(1−x)IIIF3 fluorides with the defect pyrochlore structure (Fdm, Z=8). The room temperature structure of CsFe2F6 was determined using X-ray powder diffraction technique. This phase was found to be ordered with the Pnma space group. The study of the temperature stability of orthorhombic structure by differential scanning calorimeter between 100 K and 700 K has shown a succession of phase transitions. The Pnma (Z=4)→Imma (Z=4)→I41/amd (Z=4)→Fdm (Z=8) structural sequence was proposed to occur within a rather narrow temperature range 500–560 K. The mechanism of structural transition has been mainly associated with the rotation of (MF6) octahedra and small displacements of some Fe atoms. This assumption is in good agreement with the low experimental entropy value, which is characteristic for displacive transformations.
Смотреть статью,
WOS,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Knyazev Yu.V., Ivanova N. B., Kazak N. V., Platunov M. S., Bezmaternykh L. N., Velikanov D. A., Vasiliev A. D., Ovchinnikov S. G., Yurkin G. Yu.
Заглавие : Crystal structure and magnetic properties of Mn substituted ludwigite Co3O2BO3
Место публикации : J. Magn. Magn. Mater.: Elsevier Science BV, 2012. - Vol. 324, Is. 6. - P.923-927. - ISSN 0304-8853, DOI 10.1016/j.jmmm.2011.07.044
Примечания : Cited References: 15. - The study was supported by the Russian Foundation for Basic Research (Project no. 09-02-00171-a), the Federal Agency for Science and Innovation (Rosnauka) (Project no. MK-5632.2010.2), the Physical Division of the Russian Academy of Science, the program "Strongly Correlated Electrons", Project 2.3.1.
Предметные рубрики: BOND VALENT SUMS
COORDINATION CHEMISTRY
OXIDATION -STATE
O BONDS
COMPLEXES
MANGANESE
COBALT
Ключевые слова (''Своб.индексиров.''): transition metal oxyborate--distinct crystallographic position--spin glass magnetic ordering
Аннотация: The needle shape single crystals Co3−x MnxO2BO3 with ludwigite structure have been prepared. According to the X-ray diffraction data the preferable character of distinct crystallographic positions occupation by Mn ions is established. Magnetization field and temperature dependencies are measured. Paramagnetic Curie temperature value Θ=−100 K points out the predominance of antiferromagnetic interactions. Spin-glass magnetic ordering takes the onset at TN=41 K. The crystallographic and magnetic properties of Co3O2BO3:Mn are compared with the same for the isostructural analogs Co3O2BO3 and CoO2BO3:Fe.
Смотреть статью,
Scopus,
WoS,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Astakhov A. M., Vasiliev A. D., Revenko V. A.
Заглавие : Crystal and molecular structure of 1-phenyl-2-nitroguanidine
Место публикации : J. Struct. Chem.: Springer, 2012. - Vol. 53, Is. 5. - P.1013-1016. - ISSN 0022-4766, DOI 10.1134/S0022476612050265
Примечания : Cited References: 12
Ключевые слова (''Своб.индексиров.''): nitrimines--nitroguanidine--single crystal x-ray diffraction study--molecular structure
Аннотация: The molecular structure of 1-phenyl-2-nitroguanidine is nonplanar, but contains two almost planar fragments: nitroguanyl and phenyl groups. Unlike previously studied nitroguanidines, in 1-phenyl-2-nitroguanidine, the nitro group is turned to the secondary amino group. However, the structural parameters of the nitroguanyl group are little different from those of nitroguanidine and its alkyl derivatives. In the benzene ring, the symmetry in the geometric parameters is not observed, which is explained by the intermolecular interaction with the neighboring molecule.
Смотреть статью,
Scopus,
WoS,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Atuchin V. V., Isaenko L. I., Kesler V. G., Lin Z. S., Molokeev M. S., Yelisseyev A. P., Zhurkov S. A.
Заглавие : Exploration on anion ordering, optical properties and electronic structure in K3WO3F3 elpasolite
Место публикации : J. Solid State Chem. - 2012. - Vol. 187. - P.159-164. - ISSN 0022-4596, DOI 10.1016/j.jssc.2011.12.037
Примечания : Cited References: 50. - This study is partly supported by SB RAS Project No. 34. ZSL acknowledges the funding support of No. 91022036, 11174297, 2010CB630701, and 2011CB922204 in China. Authors also wish to thank V. D. Fokina for microcaloric measurements.
Предметные рубрики: PHASE-TRANSITIONS
CRYSTAL-GROWTH
FERROELECTRIC K3WO3F3
SOLID-STATE
OXYFLUORIDE
FLUORIDE
POLAR
CS
(NH4)(3)MOO3F3
APPROXIMATION
Anion ordering
Chemical routes
Elpasolite
First-priciples calculation
Forbidden band
Low temperatures
Non-linear optical coefficients
Nonlinear optical crystal
Optical transparency
Oxyfluorotungstate
Room temperature
Ключевые слова (''Своб.индексиров.''): oxyfluorotungstate--structure--nonlinear optical crystals--electronic and optical properties--first-principles calculations
Аннотация: Room-temperature modification of potassium oxyfluorotungstate, G(2)-K3WO3F3, has been prepared by low-temperature chemical route and single crystal growth. Wide optical transparency range of 0.3-9.4 mu m and forbidden band gap E-g=4.32 eV have been obtained for G(2)-K3WO3F3 crystal. Meanwhile, its electronic structure has been calculated with the first-principles calculations. The good agreement between the theorectical and experimental results have been achieved. Furthermore, G(2)-K3WO3F3 is predicted to possess the relatively large nonlinear optical coefficients. (C) 2012 Elsevier Inc. All rights reserved.
Смотреть статью,
WoS,
Scopus,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Avramov P. V., Fedorov D. G., Sorokin P. B., Sakai S., Entani S., Ohtomo M., Matsumoto Y., Naramoto H.
Заглавие : Intrinsic edge asymmetry in narrow zigzag hexagonal heteroatomic nanoribbons causes their subtle uniform curvature
Место публикации : J. Phys. Chem. Lett. - 2012. - Vol. 3, Is. 15. - P.2003-2008. - ISSN 1948-7185, DOI 10.1021/jz300625t
Примечания : Cited References: 42. - This work was supported by JAEA Research fellowship (P.V.A.). P.V.A. also acknowledges JAEA ASRC and the Molecular Spintronics Group for hospitality and fruitful collaboration. D.G.F. thanks Prof. Kazuo Kitaura for many fruitful discussions and the Next Generation SuperComputing Project, Nanoscience Program and Strategic Programs for Innovative Research (MEXT, Japan) for financial support. This work was partially supported by Russian Ministry of Education and Science (Contract No. 16.552.11.7014) (P.B.S.).
Предметные рубрики: MOLECULAR-ORBITAL METHOD
WALLED CARBON NANOTUBES
GRAPHENE NANORIBBONS
ELECTRONIC-STRUCTURE
OPTICAL-TRANSITIONS
SOLIDS
BOND
Aromatic rings
Conical surfaces
Finite length
Fragment molecular orbital methods
Graphene nanoribbons
Intrinsic curvature
Nanoribbons
Out-of-plane
Structural stress
Ключевые слова (''Своб.индексиров.''): zigzag nanoribbons--hexagonal atomic lattices--fluorine-terminated graphene
Аннотация: The atomic and electronic structure of narrow zigzag nanoribbons with finite length, consisting of graphene terminated by fluorine on one side, hexagonal (h) h-BN, and h-SiC were studied with density functional theory. It is found that the asymmetry of nanoribbon edges causes a uniform curvature of the ribbons due to structural stress in the aromatic ring plane. Narrow graphene nanoribbons terminated with fluorine on one side demonstrate a considerable out-of-plane bend, suggesting that the nanoribbon is a fraction of a conical surface. It is shown that the intrinsic curvature of the narrow nanoribbons destroys the periodicity and results in a systematic cancellation of the dipole moment. The in- and out- of-plane curvature of thin arcs allows their closure in nanorings or cone fragments of giant diameter. Using the fragment molecular orbital method, we optimized the structure of a planar giant arc and a closed ring of h-BN with a diameter of 105 nm.
Смотреть статью,
Scopus,
WoS,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Aver'yanov E. M.
Заглавие : Mean polarizability of molecules and anisotropy of the Lorentz tensor upon a nematic-smectic a phase transition: Their behavior in a homologous series
Место публикации : Russ. J. Phys. Chem. A: MAIK Nauka-Interperiodica / Springer, 2012. - Vol. 86, Is. 5. - P.720-728. - ISSN 0036-0244, DOI 10.1134/S0036024412050044
Примечания : Cited References: 37
Предметные рубрики: CHOLESTERIC LIQUID-CRYSTALS
REFRACTIVE-INDEX DATA
A PHASE
MESOMORPHIC PROPERTIES
ORIENTATIONAL ORDER
OPTICAL ANISOTROPY
LOCAL-FIELD
POLYMORPHISM
TEMPERATURE
A-monotone
Alkyl chain
Experimental values
Homologous series
Homologues
Limiting values
Lorentz
Mesophases
Molecular core
Molecular polarizabilities
Nematic
Orientational order parameters
Polarizabilities
Polarizability density
Quadratic dependence
A-monotone
Smectic
Smectic phase
Smectic phasis
Smectic-A phasis
Ключевые слова (''Своб.индексиров.''): molecular polarizability--anisotropy--phase transition--nematic--smectic--homologues
Аннотация: Experimental values of the mean polarizability of molecules, (gamma) over bar, and components of the Lorentz tensor, L-j, in the nematic and smectic A phases are obtained for a homologous series of n-alkyl-p-(4-ethoxybenzylideneamino)-alpha-methylcinnamates. Dependences of the (gamma) over bar and L-j values on the mesophase temperature, the orientational order parameter S of molecules, and the number n in the homologous series are revealed. The quadratic dependence of (gamma) over bar (S) in the nematic and smectic phases is established that is invariant with respect to the nematic-smectic A transition. Polarizability densities of the molecular core and the alkyl chain are found from the monotone decreasing dependence (gamma) over bar (n)/v (where v is volume per one molecule) in the smectic phase. The presence (or absence) of the odd-even alternation of L-j(n) in the nematic (smectic) phase is shown. A monotone decrease in the Lorentz tensor anisotropy L with an increase in n is revealed in the smectic phase, and limiting values L-j(n - infinity) are determined.
Смотреть статью,
Scopus,
WoS,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Kuzubov A. A., Eliseeva N. S., Krasnov P. O., Tomilin F. N., Fedorov A. S., Tolstaya A. V.
Заглавие : Possibility of a 2D SiC monolayer formation on Mg(0001) and MgO(111) substrates
Место публикации : Russ. J. Phys. Chem. A: MAIK Nauka-Interperiodica / Springer, 2013. - Vol. 87, Is. 8. - P.1332-1335. - ISSN 0036-0244, DOI 10.1134/S0036024413080141
Примечания : Cited References: 25
Предметные рубрики: AB-INITIO
THIN-FILMS
NANOTUBES
ENERGY
Ключевые слова (''Своб.индексиров.''): silicon carbide monolayer--density functional theory
Аннотация: The geometrical characteristics of a 2D SiC monolayer on Mg(0001) and MgO(111) plates regarded as potential materials for growing two-dimensional silicon carbide were studied. The most favorable positions of the atoms of 2D SiC on the substrates were determined. In the 2D SiC/Mg(0001) system, unlike in 2D SiC/MgO(111), the deviation of the carbon atom from the silicon carbide monolayer was insignificant (0.08 ). Consequently, magnesium can be used as a substrate for growing two-dimensional silicon carbide. The use of MgO(111) is not recommended because of a significant distortion of the 2D SiC surface.
Смотреть статью,
Смотреть статью,
WOS,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Vasiliev A. D., Zel'bst E. A., Soldatenko A. S., Bolgova Yu.I., Trofimova O. M., Voronkov M. G.
Заглавие : Synthesis and molecular structure of cobalt(II) complex with 1-(1-silatranylmethyl)-1,2,4-triazole
Место публикации : Struct. Chem.: Springer/Plenum Publishers, 2013. - Vol. 24, Is. 4. - P.1001-1005. - ISSN 1040-0400, DOI 10.1007/s11224-012-0121-0
Примечания : Cited References: 24
Предметные рубрики: REACTIVITY
DERIVATIVES
CRYSTAL
SPECTRA
Ключевые слова (''Своб.индексиров.''): complexes--1-(1-silatranylmethyl)-1,2,4-triazole--cobalt dichloride--x-ray diffraction
Аннотация: Reaction of cobalt chloride with 1-(1-silatranylmethyl)-1,2,4-triazole in benzene afforded complex CoCl2 center dot 2L (L = 1-(1-silatranylmethyl)-1,2,4-triazole). It was isolated as the solvate [CoCl2 center dot 2L]center dot CH2Cl2 (1) by recrystallization from dichloromethane and structurally characterized by single-crystal X-ray diffraction. It crystallizes in the monoclinic space group P2(1)/m with a = 6.798(2) E, b = 20.326(5) E, c = 11.005(3) E, and Z = 4. The cobalt atom is in slightly distorted square-planar environment, coordinated to two nitrogen atoms from two ligands and two chloride ions.
Смотреть статью,
WoS,
WOS,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Golovnev N. N., Molokeev M. S., Belash M. Y.
Заглавие : Crystal structure of potassium 2-thiobarbiturate
Место публикации : J. Struct. Chem.: MAIK Nauka-Interperiodica / Springer, 2013. - Vol. 54, Is. 3. - P.566-570. - ISSN 0022-4766, DOI 10.1134/S0022476613030141
Примечания : Cited References: 18. - The work was supported by the grant of the President of the Russian Federation for the support of leading scientific schools of the Russian Federation (NSh-4828.2012.2) and the Federal Targeted Program "Scientific and Scientific Pedagogical Personnel of Innovative Russia, 2009-2013" (State contracts Nos. 02.740.11.0269 and 02.740.11.0629).
Предметные рубрики: ACID
Ключевые слова (''Своб.индексиров.''): crystal structure--potassium thiobarbiturate--hydrogen bonds--pi-pi interaction
Аннотация: The crystal and molecular structure of potassium thiobarbiturate C4H3KN2O2S (C4H4N2O2S-2-thiobarbituric acid, H(2)TBA) is determined. Crystallographic data for KHTBA are as follows: a = 11.2317(17) , b = 3.8687(6) , c = 14.557(2) , beta = 97.448(4)A degrees, V = 627.18(17) (3), space group P2/c, Z = 4. Each potassium ion is linked with four oxygen atoms and two S atoms forming a distorted octahedron. N-HaEuro broken vertical bar O and C-HaEuro broken vertical bar S hydrogen bonds form a branched three-dimensional network. The structure is also stabilized by the pi-pi interaction of heterocyclic HTBA(-) ions.
Смотреть статью,
WoS,
WOS,
Читать в сети ИФ
Найти похожие

10.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Vasiliev A. D., Golovnev N. N.
Заглавие : Crystal structure of two hydrate phases of ciprofloxacindi-um tetrachloridocobaltate(II)
Место публикации : J. Struct. Chem.: MAIK Nauka-Interperiodica / Springer, 2013. - Vol. 54, Is. 3. - P.607-612. - ISSN 0022-4766, DOI 10.1134/S0022476613030219
Примечания : Cited References: 9
Ключевые слова (''Своб.индексиров.''): ciprofloxacindi-um tetrachloridocobaltate(ii)--crystal structure--hydrogen bonds--pi-pi interaction
Аннотация: New (C17H20FN3O3)(2)[CoCl4](2)center dot 3H(2)O (I) and C17H20FN3O3[CoCl4]center dot H2O (II) compounds, where C17H18FN3O3 is ciprofloxacin (CfH), are synthesized and their crystal structures are determined. Crystallographic data for I: a = 18.441(5) , b = 9.030(3) , c = 27.551(8) , V = 4588(4) (3), space group Pca2(1), Z = 4; for II: a = 9.305(3) , b = 9.885(3) , c = 12.999(4) , alpha = 82.782(4)A degrees, beta = 72.954(4)A degrees, gamma = 89.736(4)A degrees, V = 1133(1) (3), P-1 space group, Z = 2. Both structures contain CfH (3) (2+) ion pairs bonded by the pi-pi interaction. Additionally, in the crystal of I there is a stacking interaction between the pi clouds of aromatic rings and hydrogen atoms of the cyclopropyl group linking the pairs of molecules with each other. The structure of the centrosymmetric crystal of triclinic phase II is also formed from CfH (3) (2+) ion pairs bonded by the pi-pi interaction, which, in this case, are not independent because they are related by the symmetry center. Hydrogen bonds form a branched three-dimensional network linking the CfH (3) (2+) and CoCl (4) (2-) ions and water molecules.
Смотреть статью,
WoS,
WOS,
Читать в сети ИФ
Найти похожие