Главная
Авторизация
Фамилия
Пароль
 

Базы данных


Труды сотрудников ИФ СО РАН - результаты поиска

Вид поиска

Область поиска
в найденном
 Найдено в других БД:Каталог книг и брошюр библиотеки ИФ СО РАН (7)
Формат представления найденных документов:
полный информационныйкраткий
Отсортировать найденные документы по:
авторузаглавиюгоду изданиятипу документа
Поисковый запрос: (<.>K=density<.>)
Общее количество найденных документов : 203
Показаны документы с 1 по 20
1.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Mironov V. L., Karavayskiy A. Yu., Lukin Y. I., Molostov I. P.
Заглавие : A dielectric model of thawed and frozen Arctic soils considering frequency, temperature, texture and dry density
Место публикации : Int. J. Remote Sens. - 2020. - Vol. 41, Is. 10. - P.3845-3865. - ISSN 0143-1161, DOI 10.1080/01431161.2019.1708506. - ISSN 1366-5901 (eISSN)
Примечания : Cited References: 39
Аннотация: A dielectric model was developed for thawed and frozen mineral soils, based on the refractive mixing dielectric formula and the dielectric measurement data for three soils collected in the Arctic tundra of the Yamal Peninsula. The refractive mixing dielectric model was used in conjunction with the Debye multi relaxation equations as a theoretical model to fit the measured complex relative permittivity spectra as a function of soil moisture and temperature. As a result, the dielectric spectroscopic parameters for the various components of water in the soil, such as the low- and high-frequency limits of the complex relative permittivity, the times of the corresponding relaxations, and the specific conductivity, were simultaneously determined for soils with different clay contents for all measured temperatures. As the theoretical temperature dependences of these parameters, the Clausius–Mossotti, Eyring, and linear equations for the conductivity were used. By using approximations of the measured data with these formulas, the parameters of the temperature-dependent model were derived, such as the coefficient of volume expansion, energy and entropy of activation, and coefficient of thermal conductivity. A set of the parameters discussed above in conjunction with the refractive mixing formula is a temperature- and mineralogically dependent multi-relaxation spectroscopic dielectric model, which enables estimation of the permittivity of moist soils as a function of dry soil density, moisture, frequency, temperature, and texture. The statistical error of the proposed dielectric model was estimated in terms of the normalized root-mean-square error (nRMSE), which was equal to 5% and 25% for the dielectric constant and dielectric loss factor, respectively.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие
2.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Mikhaleva N. S., Visotin M. A., Popov Z. I., Kuzubov A. A., Fedorov A. S.
Заглавие : Ab initio and empirical modeling of lithium atoms penetration into silicon
Место публикации : Comput. Mater. Sci.: Elsevier, 2015. - Vol. 109. - P.76-83. - ISSN 0927-0256, DOI 10.1016/j.commatsci.2015.06.024
Примечания : Cited References: 69. - The authors would like to thank the Institute of Computational Modeling SB RAS, Krasnoyarsk, Information Technology Centre Novosibirsk State University, for providing access to their computational resources. The reported study was supported by RFBR, research project No. 14-02-31071, 14-02-31309, 12-02-00640, by the Council of the President of the Russian Federation for Support of Young Scientists and Leading Scientific Schools (project No. NSh-2886.2014.2), Increase Competitiveness Program of NUST "MISiS" (No. K2-2015-033). The authors also would like to thank Prof. Stephan Irle and L.R. Moskvina for fruitful discussions and helpful ideas.
Предметные рубрики: LONG CYCLE LIFE
CORE-LEVEL SPECTROSCOPY
CARBON-COATED SILICON
AUGMENTED-WAVE METHOD
ION BATTERIES
MOLECULAR-DYNAMICS
INTERATOMIC POTENTIALS
ELECTRONIC-STRUCTURE
CRYSTALLINE SILICON
SI(100)2X1 SURFACE
Ключевые слова (''Своб.индексиров.''): li-ion batteries--silicon--surface diffusion--li diffusion--density functional theory--molecular dynamics
Аннотация: A process of lithium atoms penetration into silicon (1 0 0) subsurface layers was investigated with the help of DFT method. It was shown that, while the concentration of lithium adatoms on reconstructed (1 0 0) silicon surface is low, the bonding energy of lithium atoms in the subsurface layers is smaller than the bonding energy on the surface, so lithium atoms are unlikely to migrate into the crystal. When the (1 0 0) silicon surface is covered by 2 layers of lithium, migration into the subsurface layer becomes favorable. In addition to this, the reconstruction of the surface changes to the form with symmetric dimers as the concentration increases. Thus, all possible lithium migration paths become energy-wise equal, so the rate of lithium atom transfer into silicon crystal rises. In addition to the ab initio calculations, an ad-hoc empirical interatomic potential was developed and the kinetics of lithium diffusion into silicon were studied. It was shown that lithium penetration proceeds in a layer-by-layer way with a sharp border between undoped and lithiated silicon. This is accounted for the fact that, once a tetrahedral interstice is occupied by a lithium atom, the migration barriers between the adjacent interstices become lower and the rate of diffusion increases. © 2015 Elsevier B.V. All rights reserved.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие
3.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Avramov P. V., Sakai S., Entani S., Matsumoto Y., Naramoto, Hiroshi
Заглавие : Ab initio LC-DFT study of graphene, multilayer graphenes and graphite
Место публикации : Chem. Phys. Lett.: Elsevier Science BV, 2011. - Vol. 508, Is. 1-3. - P.86-89. - ISSN 0009-2614, DOI 10.1016/j.cplett.2011.04.016
Примечания : Cited References: 32. - This work was supported by JAEA Research fellowship (P.V.A.). P.V.A. also acknowledges JAEA ASRC and Molecular Spintronics Group for hospitality and fruitful collaboration.
Предметные рубрики: DENSITY
NANORIBBONS
PERFORMANCE
FUNCTIONALS
FULLERENE
COBALT
FILMS
Аннотация: Atomic structure of graphene, bi-, tri-, tetralayer graphenes and graphite as well was studied using ab initio HSE, LDA and PBE DFT approaches in periodic boundary conditions. Based on comparison of theoretical results with experimental data the performance of the methods was estimated. It was found that long-range corrected HSE potential is the most reliable DFT approximation to reproduce the atomic structure of weakly bound multilayer graphenes and graphite as well. (C) 2011 Elsevier B. V. All rights reserved.
WoS,
Scopus,
Смотреть статью,
Читать в сети ИФ
Найти похожие
4.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Artyushenko P. V., Tomilin F. N., Kuzubov A. A., Ovchinnikov S. G., Tsikalova P. E., Ovchinnikova T. M., Soukhovolsky V. G.
Заглавие : Action of the atomic and electronic structure of pheromone molecules on the effectiveness of communication in xylophagous insects
Коллективы : RFBR [13-04-00375, 16-04-00132]
Место публикации : J. Struct. Chem.: MAIK Nauka-Interperiodica / Springer, 2016. - Vol. 57, Is. 2. - P.287-293. - ISSN 0022-4766, DOI 10.1134/S0022476616020074. - ISSN 1573-8779(eISSN)
Примечания : Cited References:27. - This work was supported by RFBR projects Nos. 13-04-00375 and16-04-00132.
Предметные рубрики: Monochamus-galloprovincialis coleoptera
Density-functional theories
Beetle Ips-typographus
Pine sawyer beetle
Aggregation pheromone
Cerambycidae
Attraction
Components
Attack
Set
Ключевые слова (''Своб.индексиров.''): atomic and electronic structure--functional density methods--absorption--spectra--excited states--xylophages--pheromones
Аннотация: The B3LYD /6-31(p,d) density functional method is applied to pheromones of the forest xylophagous insects Ips typographus L., Monochamus urussovi Fisch., and Monochamus galloprovincialis Oliv. to calculate the absorption spectra and find excited states. The calculated results are used to assess the possible activity of the molecules when they are affected by solar radiation.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие
5.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Altin S., Gokhfeld D. M.
Заглавие : Magnetization loops and pinning force of Bi-2212 single-crystal whiskers
Место публикации : Physica C. - 2011. - Vol. 471, Is. 7-8. - P.217-221. - ISSN 0921-4534, DOI 10.1016/j.physc.2011.01.006
Примечания : Cited References: 40. - The work is supported by Project No. 7 of RAS Program "Quantum physics of condensed matter", Grant No. 13 of Lavrentyev competition of young researchers of SB RAS and Scientific and Technical Research Council of Turkey (TUBITAK) under Contract No. TUBITAK-109T747.
Предметные рубрики: T-C SUPERCONDUCTORS
HIGH-TEMPERATURE SUPERCONDUCTORS
JOSEPHSON VORTICES
GROWTH
BI2SR2CACU2O8+DELTA
DENSITY
STATE
FIELD
MELT
Ключевые слова (''Своб.индексиров.''): bi-2212--whisker--magnetization loop--pinning force--extended critical state model--bi-2212--extended critical state model--magnetization loop--pinning force--whisker--bi-2212--extended critical state model--magnetization loop--pinning force--whisker--flux pinning--magnetic fields--magnetization--critical current density (superconductivity)
Аннотация: Dependence of magnetization on applied magnetic field for single-crystal Bi-2212 whiskers was measured at different temperatures. Symmetric and asymmetric magnetization loops were successfully described by the extended critical state model (the extended Valkov-Khrustalev model). Pinning force of whiskers was investigated. (C) 2011 Elsevier B.V. All rights reserved.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
6.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Fedorov D.G., Kitaura K., Avramov P. V., Jensen J.H.
Заглавие : Analytic gradient for the adaptive frozen orbital bond detachment in the fragment molecular orbital method
Место публикации : Chem. Phys. Lett. - 2009. - Vol. 477, Is. 1-3. - P.169-175. - JUL 28. - ISSN 0009-2614, DOI 10.1016/j.cplett.2009.06.072
Примечания : Cited Reference Count: 49. - Гранты: We thank Professor M. Suenaga of Kyushu University for continuing his development of the modeling software FACIO and its FMO interface. D. G. F. and K. K. were supported by the a Grant-in- Aid for Scientific Research (JSPS, Japan) and the Next Generation SuperComputing Project, Nanoscience Program (MEXT, Japan). J.H.J. was supported by a Skou Fellowship from the Danish Research Agency (Forskningsradet for Natur og Univers).Финансирующая организация: JSPS, Japan; Next Generation SuperComputing Project; MEXT, Japan; Danish Research Agency
Предметные рубрики: DENSITY-FUNCTIONAL THEORY
GEOMETRY OPTIMIZATIONS
SEMICONDUCTOR NANOWIRES
SILICON NANOWIRES
METHOD FMO
ENERGY
SURFACES
RECONSTRUCTION
CHEMISTRY
PROTEINS
Ключевые слова (''Своб.индексиров.''): energy gradients--fragment molecular orbital methods--future applications--geometry optimization--numerical criteria--silicon nanowires--molecular modeling--molecular orbitals
Аннотация: We have developed and implemented the analytic energy gradient for the bond detachment scheme in the fragment molecular orbital method (FMO) suitable to describe solids, and applied it to the geometry optimization of a silicon nanowire at several levels of theory. In addition, we have examined in detail the effects of the particular choice of the fragmentation upon the accuracy and introduced a number of numerical criteria to characterize the errors. The established route is expected to provide guidance for future applications of FMO to surfaces, solids and nanosystems. (C) 2009 Elsevier B. V. All rights reserved.
WOS,
Scopus,
eLibrary
Найти похожие
7.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Petrov M. I., Gokhfeld D. M., Balaev D. A., Shaihutdinov K. A., Kummel R.
Заглавие : Andreev reflections and experimental current-voltage characteristics of break junctions of polycrystalline HTSC
Место публикации : Physica C: ELSEVIER SCIENCE BV, 2004. - Vol. 408: 7th International Conference on Materials and Mechanisms of Superconductive and High Temperature Superconductors (MAY 25-30, 2003, Rio de Janeiro, BRAZIL). - P620-622. - ISSN 0921-4534, DOI 10.1016/j.physc.2004.03.085
Примечания : Cited References: 3
Ключевые слова (''Своб.индексиров.''): andreev reflections--break junction--current-voltage characteristics--andreev reflections--break junction--current-voltage characteristics--andreev reflections--break junctions--elastic scattering--lattice defects--negative differential resistance--electric fields--heuristic methods--hysteresis--microcracks--polycrystalline materials--probability density function--quasicrystals--superconducting materials--yttrium barium copper oxides--current voltage characteristics
Аннотация: The temperature evolution of current-voltage characteristics (CVCs) of break junctions made from polycrystalline Y0.75Lu0.25Ba2Cu3O7 and La1.85Sr0.15CuO4 is investigated. The experimental CVCs have hysteretic features that reflect a part of a curve with negative differential resistance. The temperature evolution of the CVCs is discussed within the framework of the Kummel-Gunsenheimer-Nicolsky theory for superconductor/normal-metal/superconductor junctions considering multiple Andreev reflections. It is shown that the shape of the CVCs of break junctions is determined by the ratio of the number of "short" and "long" intergrain normal regions in the polycrystalline HTSC under investigation. (C) 2004 Elsevier B.V. All rights reserved.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
8.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Gokhfeld D. M., Savitskaya N. E., Popkov S. I., Kuzmichev N. D., Vasyutin M. A., Balaev D. A.
Заглавие : Anisotropic magnetization of an NbN film
Место публикации : J. Exp. Theor. Phys. - 2022. - Vol. 134, Is. 6. - P.707-712. - ISSN 10637761 (ISSN), DOI 10.1134/S1063776122060097
Примечания : Cited References: 31. - We are grateful to I.V. Nemtsev for measurements on the scanning electron microscope, S.A. Skorobogatov for his help in magnetic measurements (scanning electron microscopy and magnetic measurements have been performed at the Krasnoyarsk Regional Collective Usage Center of the Federal Research Center “Krasnoyarsk Scientific Center, Siberian Branch, Russian Academy of Sciences”)
Аннотация: The structural and magnetic properties of a niobium nitride (NbN) film prepared by reactive sputtering onto a quartz substrate are investigated. It is shown using scanning electron microscopy that the film has a columnar structure with a diameter of crystallite columns of about 50 nm. The film magnetization loops are measured for the field orientation parallel and perpendicular to its surface. Based on the experimental data, the critical current densities of the film are estimated in both cases. For the field parallel to the film surface, the estimate is 6.5 × 104 A/cm2 at the liquid helium temperature. For the field perpendicular to the surface, the critical current density is close to the depairing current density (107 A/cm2). Analysis of the results based on different models of magnetic vortex pinning in superconductors shows that in the former case, pinning occurs at the boundaries of columns in the bulk of the sample, while in the latter case, it is determined by the influence of the surface barrier.
Смотреть статью,
Scopus
Найти похожие
9.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Aplesnin S. S.
Заглавие : Formation of a spin density wave in copper metaborate by a spin polaron
Место публикации : J. Phys.: Condens. Matter: IOP PUBLISHING LTD, 2004. - Vol. 16, Is. 32. - P5907-5914. - ISSN 0953-8984, DOI 10.1088/0953-8984/16/32/023
Примечания : Cited References: 12
Предметные рубрики: SOLITON LATTICE
CUB2O4
Ключевые слова (''Своб.индексиров.''): absorption--correlation methods--electric fields--infrared radiation--magnetization--mathematical models--polarons--specific heat--intraband transition--optical conductivity--spin density waves--spin polaron--copper compounds
Аннотация: Formation of incommensurate three-dimensional magnetic order below T* similar to 10 K in CuB2O4 is explained on the basis of strong correlation between the holes and localized spins. The Kondo lattice model is analysed for the case where spin polarons are the elementary excitations. The origin of the low-temperature specific heat maximum at T similar to 5 K is associated with a displacement of the polaron band bottom. A set of anomalies in the temperature dependence of the conductivity, shift of the optical conductivity maximum in the range of energies 0.02-0.12 eV and decreasing of the infrared absorption intensity is predicted.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
10.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Aplesnin S. S.
Заглавие : Two-dimensional quantum spin liquid with S=1/2 spins interacting with acoustic phonons
Разночтения заглавия :авие SCOPUS: Two-dimensional quantum spin liquid with S = 1/2 spins interacting with acoustic phonons
Место публикации : Phys. Lett. A. - 2004. - Vol. 333, Is. 5-6. - P.446-449. - ISSN 0375-9601, DOI 10.1016/j.physleta.2004.10.064
Примечания : Cited References: 11
Предметные рубрики: ANTIFERROMAGNET
Ключевые слова (''Своб.индексиров.''): spin-phonon interactions--spin-liquid--spinon excitations--spin-liquid--spin-phonon interactions--spinon excitations--ferromagnetic material--acceleration--acoustics--article--density--energy--liquid--magnetic field--mathematical analysis--monte carlo method--phonon--quantum mechanics
Аннотация: The spin density of states of a two-dimensional antiferromagnet in magnetic field having spins-1/2 and interacting with acoustic phonons is investigated in the nonadiabatic approximation using the quantum Monte Carlo method. It is found the gap energy A in the single particle spin excitations spectrum closes at magnetic field Delta similar or equal to H-c, W-ph W-s and Delta similar or equal to (1/2)H-c, W-ph W-s, where W-ph and W-s are the bandwidths of phonon and spin excitations in antiferromagnet. (C) 2004 Elsevier B.V All rights reserved.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
11.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Korshunov M. M., Ovchinnikov S. G., Gavrichkov V. A., Nekrasov I. A., Pchelkina Z. V., Anisimov V. I.
Заглавие : Application of the new LDA plus GTB method for the band structure calculation of n-type cuprates
Разночтения заглавия :авие SCOPUS: Application of the new LDA+GTB method for the band structure calculation of n-type cuprates
Место публикации : Physica B: ELSEVIER SCIENCE BV, 2006. - Vol. 378-80: International Conference on Strongly Correlated Electron Systems (SECES 05) (JUL 26-30, 2005, Vienna, AUSTRIA). - P459-460. - ISSN 0921-4526, DOI 10.1016/j.physb.2006.01.340
Примечания : Cited References: 11
Предметные рубрики: SUPERCONDUCTIVITY
PARAMETERS
DENSITY
Ключевые слова (''Своб.индексиров.''): strongly correlated electron systems--superconductivity--n-type cuprates--n-type cuprates--strongly correlated electron systems--superconductivity--electronic structure--hamiltonians--mathematical models--oxide superconductors--perturbation techniques--intercluster hopping--n-type cuprates--strongly correlated electron systems--band structure
Аннотация: A novel hybrid scheme is proposed and applied for band structure calculations of undoped n-type cuprate Nd2CuO4. The ab initio LDA calculation is used to obtain single electron and Coulomb parameters of the multiband Hubbard-type model. In strong correlation regime the electronic structure within this model is calculated by the generalized tight-binding (GTB) method, that combines the exact diagonalization of the model Hamiltonian for a small cluster with perturbation treatment of the intercluster hopping and interactions. For Nd2CuO4, this scheme results in charge transfer insulator with value of the gap and band dispersion in agreement to the experimental data. (c) 2006 Elsevier B.V. All rights reserved.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
12.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Kodirov M. K., Popov A. K., Slabko V. V., Yakhnin V. Z.
Заглавие : Atom-density distribution in a metal vapor cell studied by 3rd-harmonic generation
Разночтения заглавия :авие SCOPUS: Atom-density distribution in a metal vapor cell studied by third-harmonic generation
Место публикации : Appl. Phys. B. - 1988. - Vol. 45, Is. 1. - P.47-52. - ISSN 0721-7269, DOI 10.1007/BF00692341
Примечания : Cited References: 20
Ключевые слова (''Своб.индексиров.''): 42.65--42.80--cesium and alloys - applications--light - nonlinear optical effects--spectroscopy - measurements--atom-density distribution--cesium vapors--metal vapor cell--third-harmonic generation--vapors
WOS,
Scopus
Найти похожие
13.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Avramov P. V., Minami S., Morokuma K., Irle S., Chernozatonskii L.A.
Заглавие : Atomic Structure and Energetic Stability of Complex Chiral Silicon Nanowires
Место публикации : J. Phys. Chem. C. - 2010. - Vol. 114, Is. 35. - P.14692-14696. - SEP 9. - ISSN 1932-7447, DOI 10.1021/jp1016399
Примечания : Cited Reference Count: 36. - Гранты: This work was supported by a CREST (Core Research for Evolutional Science and Technology) grant in the Area of High Performance Computing for Multiscale and Multiphysics Phenomena from the Japan Science and Technology Agency (JST) and a collaborative RFBR-JSPS grant No. 09-02-92107-Phi. S.I. also acknowledges support by the Program for Improvement of Research Environment for Young Researchers from Special Coordination Funds for Promoting Science and Technology (SCF) commissioned by the Ministry of Education, Culture, Sports, Science, and Technology (MEXT) of Japan. L.Ch. acknowledges support by the Presidium of Russian Academy of Sciences (Program No. 27).Финансирующая организация: CREST (Core Research for Evolutional Science and Technology); Japan Science and Technology Agency (JST); RFBR-JSPS [09-02-92107]; Special Coordination Funds for Promoting Science and Technology (SCF); Presidium of Russian Academy of Sciences [27]
Предметные рубрики: DENSITY-FUNCTIONAL METHODS
GROWTH
EXCHANGE
NANOHELICES
NANOSPRINGS
Ключевые слова (''Своб.индексиров.''): ab initio--atomic structure--chiral complexes--consecutive shifts--dft method--energetic stability--homo-lumo gaps--metastable structures--potential barriers--si atoms--silicon nanowires--unit cell parameters--atoms--chirality--electronic structure--enantiomers--metastable phases--nanowires--stereochemistry--wire--crystal atomic structure
Аннотация: Atomic and electronic structure and energetic stability of newly proposed pentagonal and hexagonal chiral complex silicon nanowires (NWs) composed of five or six (I 10) oriented crystalline fragments were studied using the ab initio DFT method. The chirality of the wires was caused by consecutive shifts of each fragment by 1/5 or 1/6 of the wire unit cell parameter and rotations of 4 degrees and 3.3 degrees for achiral pentagonal or hexagonal wires, respectively. Chirality causes the HOMO-LUMO gap to reduce by 0.1 eV. Chiral silicon nanowires are found to be metastable structures with a 4,5 (kcal/mol)/Si atom potential barrier for reversible chiral achiral transformation.
WOS,
Scopus,
eLibrary
Найти похожие
14.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Sorokin P. B., Ovchinnikov S. G., Avramov P. V., Chernozatonskii L.A., Fedorov D.G.
Заглавие : Atypical quantum confinement effect in silicon nanowires
Место публикации : J. Phys. Chem. A. - WASHINGTON: AMER CHEMICAL SOC, 2008. - Vol. 112, Is. 40. - С. 9955-9964. - OCT 9. - ISSN 1089-5639, DOI 10.1021/jp805069b
Примечания : Cited Reference Count: 25. - Гранты: This work was in part partially supported by a CREST (Core Research for Evolutional Science and Technology) grant in the Area of High Performance Computing for Multiscale and Multiphysics Phenomena from the Japan Science and Technology Agency (JST) as well as by Russian Fund of Basic Researches (grant 08-02-01096) (L.A.C.). P.V.A. acknowledges the encouragement of Dr. Keiji Morokuma, Research Leader at Fukui Institute for Fundamental Chemistry. The geometry of all presented structures was visualized by ChemCraft software.SUP25/SUP L.A.C. acknowledges I. V. Stankevich for help and fruitful discussions. P.B.S. is grateful to the Joint Supercomputer Center of the Russian Academy of Sciences for access to a cluster computer for quantum-chemical calculations.Финансирующая организация: Japan Science and Technology Agency (JST); Russian Fund of Basic Researches [08-02-01096]
Предметные рубрики: ELECTRONIC-STRUCTURE
OPTICAL-PROPERTIES
SI
DENSITY
WIRES
EXCHANGE
ATOMS
DOTS
Ключевые слова (''Своб.индексиров.''): electric wire--energy gap--gallium alloys--mathematical models--nanostructured materials--nanostructures--nanowires--quantum confinement--quantum electronics--semiconductor quantum dots--silicon--ami methods--band gaps--blue shifts--dinger equations--linear junctions--monotonic decreases--quantum confinement effects--quantum dots--semiempirical--silicon nanowires--system sizes--theoretical models--nanocrystalline silicon--nanowire--quantum dot--silicon--article--chemistry--electron--quantum theory--electrons--nanowires--quantum dots--quantum theory--silicon
Аннотация: The quantum confinement effect (QCE) of linear junctions of silicon icosahedral quantum dots (IQD) and pentagonal nanowires (PNW) was studied using DFT and semiempirical AM1 methods. The formation of complex IQD/PNW structures leads to the localization of the HOMO and LUMO on different parts of the system and to a pronounced blue shift of the band gap; the typical QCE with a monotonic decrease of the band gap upon the system size breaks down. A simple one-electron one-dimensional Schrodinger equation model is proposed for the description and explanation of the unconventional quantum confinement behavior of silicon IQD/PNW systems. On the basis of the theoretical models, the experimentally discovered deviations from the typical QCE for nanocrystalline silicon are explained.
WOS,
Scopus,
eLibrary
Найти похожие
15.

Вид документа : Статья из сборника (однотомник)
Шифр издания :
Автор(ы) : Aver'yanov E. M.
Заглавие : Change in the spectrum of the polarizability density of molecules at the smectic-A - crystal-B phase transition
Коллективы : European Conference on Liquid Crystals, Московский государственный университет им. М.В. Ломоносова
Место публикации : 14th Eur. Conf. Liq. Cryst. (ECLC): conf. programme/ чл. нац. орг. и прогр. ком. V. Ya. Zyryanov. - 2017. - Ст.P4. - Poster
Примечания : Библиогр.:
Материалы конференции,
Материалы конференции
Найти похожие
16.

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
17.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Avramov P. V., Sorokin P. B., Fedorov A. S., Fedorov D. G., Maeda Y.
Заглавие : Band-gap unification of partially Si-substituted single-wall carbon nanotubes
Место публикации : Phys. Rev. B: AMER PHYSICAL SOC, 2006. - Vol. 74, Is. 24. - Ст.245417. - ISSN 1098-0121, DOI 10.1103/PhysRevB.74.245417
Примечания : Cited References: 72
Предметные рубрики: SILICON-CARBIDE NANOTUBES
DENSITY-FUNCTIONAL THEORY
TOTAL-ENERGY CALCULATIONS
WAVE BASIS-SET
ELECTRONIC-STRUCTURE
AB-INITIO
NANORODS
EXCITATIONS
TRANSITION
NANOWIRES
Аннотация: The atomic and electronic structure of a set of pristine single wall SiC nanotubes as well as Si-substituted carbon nanotubes and a SiC sheet was studied by the local-density approximation (LDA) plane wave band structure calculations. Consecutive substitution of carbon atoms by Si leads to a gap opening in the energetic spectrum of the metallic (8,8) SWCNT with approximately quadratic dependence of the band gap upon the Si concentration. The same substitution for the semiconductor (10,0) single wall carbon nanotubes (SWCNT) results in a band gap minimum (0.27 eV) at similar to 25% of Si concentration. In the Si concentration region of 12-18 %, both types of nanotubes have less than 0.5 eV direct band gaps at the Gamma-Gamma point. The calculation of the chiral (8,2) SWSi0.15C0.85NT system gives a similar (0.6 eV) direct band gap. The regular distribution of Si atoms in the atomic lattice is by similar to 0.1 eV/atom energetically preferable in comparison with a random distribution. Time dependent density functional theory (DFT) calculations showed that the silicon substitution sufficiently increases (roughly by one order of magnitude) the total probability of optical transitions in the near infrared region, which is caused by the opening of the direct band gap in metallic SWCNTs, the unification of the nature and energy of the band gaps of all SWCNT species, the large values of Si3p parallel to r parallel to Si3s radial integrals and participation of Si3d states in chemical bonding in both valence and conductance bands.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
18.

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 : Calculating the energy of vacancies and adatoms in a hexagonal SiC monolayer
Место публикации : Russ. J. Phys. Chem. A: MAIK Nauka-Interperiodica / Springer, 2012. - Vol. 86, Is. 7. - P.1091-1095. - ISSN 0036-0244, DOI 10.1134/S0036024412070138
Примечания : Cited References: 21
Предметные рубрики: INITIO MOLECULAR-DYNAMICS
ELECTRONIC-PROPERTIES
ABSORPTION-SPECTRA
Ключевые слова (''Своб.индексиров.''): silicon carbide--defects--adatoms--density functional method
Аннотация: It is noted that the development of semiconductor SiC-electronics is prevented by a low quality of grown silicon carbide single crystals. It is found that structural defects of a substrate penetrating into an epitaxial layer upon subsequent homoepitaxial growth can considerably degrade a device's characteristics. We investigate the effect of the deformation of a hexagonal SiC monolayer on vacancy stability and material properties, and study the processes of silicon and carbon adatom migration over a surface of SiC.
Смотреть статью,
Scopus,
WoS,
Читать в сети ИФ
Найти похожие
19.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Andryushin N. D., Zinenko V. I., Pavlovskii M. S., Shinkorenko A. S.
Заглавие : Calculation and Comparison of Electronic, Vibrational, Polarization, and Magnetic Properties of Double Perovskites CaMnTi2O6 and CaFeTi2O6
Место публикации : J. Exp. Theor. Phys. - 2019. - Vol. 129, Is. 6. - P.1036-1044. - ISSN 10637761 (ISSN), DOI 10.1134/S1063776119110013
Примечания : Cited References: 18. - This work was supported by the Russian Foundation for Basic Research (project no. 18-02-00130-a)
Аннотация: Vibrational, polarization, magnetic, and electronic properties of double perovskites CaMnTi2O6 and CaFeTi2O6 with a rare type of “column” ordering of divalent metal cations have been calculated based on the density functional theory. Analysis of the crystal lattice dynamics for paraelectric phase P42/nmc of both compounds has revealed that ferroelectric instability exists only in CaMnTi2O6. It is found that the structure distortion of the paraphrase of CaMnTi2O6 in the eigenvector of the unstable polar mode leads to a structure with the P42/nmc space group. The calculated spontaneous polarization for the ferroelectric phase of CaMnTi2O6 is Ps = 25 μC/cm2. The spin-polarization calculations have shown that the ground state is ferromagnetic in the CaFeTi2O6 crystal and antiferromagnetic in the CaMnTi2O6 crystal. The exchange interaction constants have been calculated using the Heisenberg model and the mean field approximation; the phase transition temperature for each compound has been estimated.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие
20.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Luna-Acosta G. A., Mendez-Bermudez J. A., Seba P., Pichugin K. N.
Заглавие : Classical versus quantum structure of the scattering probability matrix: Chaotic waveguides
Место публикации : Phys. Rev. E: AMER PHYSICAL SOC, 2002. - Vol. 65, Is. 4. - Ст.46605. - ISSN 1539-3755, DOI 10.1103/PhysRevE.65.046605
Примечания : Cited References: 47
Предметные рубрики: SEMICLASSICAL CROSS-SECTION
CONDUCTANCE FLUCTUATIONS
S-MATRIX
BALLISTIC-TRANSPORT
WEAK-LOCALIZATION
CAVITIES
COLLISIONS
MICROSTRUCTURES
DENSITY
CHANNEL
Ключевые слова (''Своб.индексиров.''): chaos theory--matrix algebra--optical waveguides--quantum theory--scattering--wave equations--chaotic cavities--chaotic waveguides--quantum structure--scattering probability matrix--quantum optics
Аннотация: The purely classical counterpart of the scattering probability matrix (SPM) \S(n,m)\(2) of the quantum scattering matrix S is defined for two-dimensional quantum waveguides for an arbitrary number of propagating modes M. We compare the quantum and classical structures of \S(n,m)\(2) for a waveguide with generic Hamiltonian chaos. It is shown that even for a moderate number of channels, knowledge of the classical structure of the SPM allows us to predict the global structure of the quantum one and, hence, understand important quantum transport properties of waveguides in terms of purely classical dynamics. It is also shown that the SPM, being an intensity measure, can give additional dynamical information to that obtained by the Poincare maps.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
 

Другие библиотеки

© Международная Ассоциация пользователей и разработчиков электронных библиотек и новых информационных технологий
(Ассоциация ЭБНИТ)