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 (1)
Формат представления найденных документов:
полный информационныйкраткий
Отсортировать найденные документы по:
авторузаглавиюгоду изданиятипу документа
Поисковый запрос: (<.>K=Resistivity<.>)
Общее количество найденных документов : 34
Показаны документы с 1 по 20
1.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Moiseenko E. T., Altunin R. R., Zharkov S. M.
Заглавие : In situ electron diffraction and resistivity characterization of solid state reaction process in Cu/Al bilayer thin films
Место публикации : Metall. Mat. Trans. A. - 2020. - Vol. 51, Is. 3. - P.1428-1436. - ISSN 10735623 (ISSN), DOI 10.1007/s11661-019-05602-5
Примечания : Cited References: 52. - The authors wish to thank the financial support from the Russian Science Foundation (Grant #18-13-00080)
Аннотация: Solid state reaction processes in Cu/Al thin films have been studied using the methods of in situ electron diffraction and electrical resistivity measurements. The solid state reaction in the Cu/Al thin films has been found to begin already at 88 °C with the formation of the Al2Cu phase in the process of thermal heating in vacuum. The phase sequence at the solid state reaction in the films under study has been determined to be the following: Al2Cu → AlCu → Al4Cu9. A model has been suggested for describing the initial formation stage of intermetallic compounds at the solid state reaction in Cu/Al thin films. According to this model, at the initial stage, the intermetallic compounds are formed as separate crystallites at the interface in the Cu/Al thin films. The suggested model can be applied both to the formation of the first phase, Al2Cu, and to the subsequent phases: AlCu and Al4Cu9. For the Al4Cu9 phase the temperature coefficient of the electrical resistivity has been determined to be equal to αAl4Cu9= 1.1 × 10−3 K−1.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие
2.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Romanova O. B., Aplesnin S. S., Udod L. V., Sitnikov M. N., Kretinin V. V., Yanushkevich K. I., Velikanov D. A.
Заглавие : Magnetoresistance, magnetoimpedance, magnetothermopower, and photoconductivity in silver-doped manganese sulfides
Коллективы : Russian Foundation for Basic Research [18-52-00009 Bel_a]; Government of Krasnoyarsk Territory; Krasnoyarsk Regional Fund of Science [18-42-240001 r_a]
Место публикации : J. Appl. Phys. - 2019. - Vol. 125, Is. 17. - Ст.175706. - ISSN 0021-8979, DOI 10.1063/1.5085701. - ISSN 1089-7550(eISSN)
Примечания : Cited References: 29. - This study was supported by the Russian Foundation for Basic Research (Project No. 18-52-00009 Bel_a). The reported study was funded by the Russian Foundation for Basic Research, Government of Krasnoyarsk Territory, Krasnoyarsk Regional Fund of Science (Project No. 18-42-240001 r_a), to the research project: "Inversion of the Sign of the Components of the Magnetoelectric Tensor on the Temperature in Films of Bismuth Garnet Ferrite Replaced by Neodymium." This study was carried out in the framework of the state task No. 3.5743.2017/6.7.
Предметные рубрики: MAGNETIC-PROPERTIES
RESISTIVITY
Аннотация: New multifunction materials in the AgXMn1‒XS (Х = 0.05) system have been synthesized and investigated in the temperature range of 77‒500 K in magnetic fields up to 12 kOe. Near the temperature of the magnetic transition (ТN = 176 K), the anomalous behavior of the temperature dependence of magnetization has been observed and has been attributed to the formation of ferrons. An analysis of the infrared spectroscopy data and I‒V characteristics has revealed the spin-polaron subband splitting. Several conductivity channels have been found from the impedance spectra. The temperature and magnetic field dependences of the carrier relaxation time have been obtained. The magnetoresistance (−21%), magnetoimpedance (−65%), magnetothermopower (−40%), and photoconductivity effects have been detected. The majority carrier type, density, and mobility have been determined from the Hall-effect measurement data. The observed effects have been explained using a ferron model.Синтезированы и исследованы новые многофункциональные материалы системы AgXMn1-XS (Х=0.05) в интервале температур 77-500К в магнитных полях до 12 кЭ. В близи температуры магнитного перехода (ТN=176К) наблюдается аномальное поведение температурной зависимости намагниченности, вызванное образованием ферронов. Найдено расщепление спин-поляронной подзоны из ИК спектроскопии и вольт-амперных характеристик. Установлено несколько каналов проводимости из спектров импеданса, отличающихся частоте. Определена зависимость времени релаксации носителей заряда от температуры и магнитного поля. Обнаружено четыре эффекта: магнитосопротивление (-21%), магнитоимпеданс (-65%), магнитотермоЭДС (-40%) и фотопроводимость. Найдены: тип, концентрация и подвижность основных носителей заряда из холловских измерений. Обнаруженные эффекты объясняются в модели ферронов.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие
3.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Pazniak H., Stevens M., Dahlqvist M., Zingsem B., Kibkalo L., Felek M., Varnakov S. N., Farle M., Rosen J., Wiedwald U.
Заглавие : Phase stability of nanolaminated epitaxial (Cr1-xFex)2AlC MAX phase thin films on MgO(111) and Al2O3(0001) for use as conductive coatings
Место публикации : ACS Appl. Nano Mat. - 2021. - Vol. 4, Is. 12. - P.13761-13770. - ISSN 25740970 (ISSN), DOI 10.1021/acsanm.1c03166
Примечания : Cited References: 51. - This work has been supported by the Deutsche Forschungsgemeinschaft (DFG) within CRC/TRR 270, project B02 (Project-ID 405553726). The calculations were carried out using supercomputer resources provided by the Swedish National Infrastructure for Computing (SNIC) at the National Supercomputer Centre (NSC) and the High Performance Computing Center North (HPC2N) partially funded by the Swedish Research Council through grant agreement no. 2018-05973. J.R. acknowledges funding from the Knut and Alice Wallenberg Foundation. Support by the Interdisciplinary Center for Analytics on the Nanoscale (ICAN) of the University of Duisburg-Essen (DFG RIsources reference: RI_00313), a DFG-funded core facility (Project nos. 233512597 and 324659309), is gratefully acknowledged. M.F. acknowledges co-funding by the government of the Russian Federation (agreement no. 075-15-2019-1886)
Аннотация: In this study, we model the chemical stability in the (Cr1-xFex)2AlC MAX phase system using density functional theory, predicting its phase stability for 0 ‹ x ‹ 0.2. Following the calculations, we have successfully synthesized nanolaminated (Cr1-xFex)2AlC MAX phase thin films with target Fe contents of x = 0.1 and x = 0.2 by pulsed laser deposition using elemental targets on MgO(111) and Al2O3(0001) substrates at 600 °C. Structural investigations by X-ray diffraction and transmission electron microscopy reveal MAX phase epitaxial films on both substrates with a coexisting (Fe,Cr)5Al8 intermetallic secondary phase. Experiments suggest an actual maximum Fe solubility of 3.4 at %, corresponding to (Cr0.932Fe0.068)2AlC, which is the highest Fe doping level achieved so far in volume materials and thin films. Residual Fe is continuously distributed in the (Fe,Cr)5Al8 intermetallic secondary phase. The incorporation of Fe results in the slight reduction of the c lattice parameter, while the a lattice parameter remains unchanged. The nanolaminated (Cr0.932Fe0.068)2AlC thin films show a metallic behavior and can serve as promising candidates for highly conductive coatings.
Смотреть статью,
Scopus,
WOS
Найти похожие
4.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Altunin R. R., Moiseenko E. T., Zharkov S. M.
Заглавие : Effect of the structural properties on the electrical resistivity of the Al/Ag thin films during the solid-state reaction
Коллективы : Russian Science FoundationRussian Science Foundation (RSF) [18-13-00080]
Место публикации : Phys. Solid State. - 2020. - Vol. 62, Is. 4. - P.708-713. - ISSN 1063-7834, DOI 10.1134/S1063783420040034. - ISSN 1090-6460(eISSN)
Примечания : Cited References: 43. - This study was supported by the Russian Science Foundation, project no. 18-13-00080.
Предметные рубрики: LIGHT-EMITTING-DIODES
PHASE-FORMATION
AG
AL
DIFFUSION
SUPPRESSION
INTERFACE
SURFACE
GROWTH
HEAT
Аннотация: Based on the results of in situ electron diffraction study of the solid-state reaction and electrical resistivity measurements on the Al/Ag thin films with an atomic ratio of Al : Ag = 1 : 3, the temperature of the reaction onset has been established and a model of the structural phase transitions has been proposed. The solid-state reaction begins at 70°C with the formation of the Al–Ag solid solution at the interface between the aluminum and silver nanolayers. It has been found that, in the course of the reaction, the intermetallic compounds γ-Ag2Al → μ-Ag3Al are successively formed. It is shown that the possibility of the formation of the μ‑Ag3Al phase during the solid-state reaction in the Al/Ag thin films depends on the aluminum-to-silver ratio, while the formation of the μ-Ag3Al phase begins only after all fcc aluminum has reacted.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие
5.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Drokin N. A., Ganiev S. M.
Заглавие : Static and dynamic characteristics of the bulk and contact electric resistivity in CDCR2SE4 under stochastic current instability
Место публикации : Fiz. Tverd. Tela. - 1992. - Vol. 34, Is. 7. - P.2122-2128. - ISSN 0367-3294
Примечания : Cited References: 21
Предметные рубрики: OSCILLATIONS
CHAOS
GE
WOS
Найти похожие
6.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Gavrichkov V. A., Ovchinnikov S. G.
Заглавие : Characteristic features of the extrinsic electric resistance in ferromagnets with low carrier density
Место публикации : Phys. Solid State: AMER INST PHYSICS, 1999. - Vol. 41, Is. 1. - P59-66. - ISSN 1063-7834, DOI 10.1134/1.1130731
Примечания : Cited References: 26
Предметные рубрики: QUANTUM TEMPERATURE OSCILLATIONS
MAGNETIC SEMICONDUCTORS
HGCR2SE4
RESISTIVITY
FILMS
Аннотация: Switching from simple semiconductors to more complicated chemical compositions, we encounter mainly nonstoichiometric or undoped compounds. Combined with other characteristic features of d(f) compounds, this can lead, together with the ordinary scattering by spin disorder in magnetic semiconductors, to an unusual impurity contribution to the total scattering of carriers even in intrinsic semiconductors. A unique scheme for calculating the energy structure of the conduction-band bottom of a ferromagnetic semiconductor and the temperature and field dependences of the impurity contribution to the resistivity is proposed on the basis of a model Hamiltonian. The computed magnetoresistance ratio is negative and has a maximum near T-c. A qualitative comparison is made between the results and the experimental temperature dependences of the Hall mobility and magnetoresistance ratio in the ternary semiconductor n-HgCr2Se4, which is nonstoichiometric with respect to the chalcogen. To identify previously unobserved temperature oscillations of the resistance, a careful analysis is made of the low-temperature part of the resistance using the relations obtained. (C) 1999 American Institute of Physics. [S1063-7834(99)01701-3].
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
7.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Kagan, M. Yu., Val'kov V. V., Aksenov S. V.
Заглавие : Effects of anisotropy and Coulomb interactions on quantum transport in a quadruple quantum-dot structure
Место публикации : Phys. Rev. B: American Physical Society, 2017. - Vol. 95, Is. 3. - Ст.035411. - ISSN 2469-9950, DOI 10.1103/PhysRevB.95.035411. - ISSN 2469-9969(eISSN)
Примечания : Cited References:62. - We acknowledge fruitful discussions with P. I. Arseyev, N. S. Maslova, V. N. Mantsevich, and R. Sh. Ikhsanov. This work was financially supported by the Comprehensive programme SB RAS No. 0358-2015-0007, the RFBR, Government of Krasnoyarsk Territory, Krasnoyarsk Region Science and Technology Support Fund, Projects No. 15-02-03082, No. 15-42-04372, No. 16-42-243056, and No. 16-42-242036. M. Yu. K. thanks the Program of Basic Research of the National Research University Higher School of Economics for support.
Предметные рубрики: 2-BAND HUBBARD-MODEL
ONE NARROW-BAND
ANOMALOUS RESISTIVITY
Аннотация: We present an analytical and numerical investigation of the spectral and transport properties of a quadruple quantum-dot (QQD) structure which is one of the popular low-dimensional systems in the context of fundamental quantum physics study, future electronic applications, and quantum calculations. The density of states, occupation numbers, and conductance of the structure were analyzed using the nonequilibrium Green's functions in the tight-binding approach and the equation-of-motion method. In particular the anisotropy of hopping integrals and on-site electron energies as well as the effects of the finite intra- and interdot Coulomb interactions were investigated. It was found out that the anisotropy of the kinetic processes in the system leads to the Fano-Feshbach asymmetrical peak. We demonstrated that the conductance of the QQD device has a wide insulating band with steep edges separating triple-peak structures if the intradot Coulomb interactions are taken into account. The interdot Coulomb correlations between the central QDs result in the broadening of this band and the occurrence of an additional band with low conductance due to the Fano antiresonances. It was shown that in this case the conductance of the anisotropic QQD device can be dramatically changed by tuning the anisotropy of on-site electron energies.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие
8.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Frolov G. I., Zhigalov V. S., Polskii A. I., Pozdnyakov V. G.
Заглавие : Study of electroconductivity in cobalt nanocrystalline films
Место публикации : Fiz. Tverd. Tela: MEZHDUNARODNAYA KNIGA, 1996. - Vol. 38, Is. 4. - P1208-1213. - ISSN 0367-3294
Примечания : Cited References: 13
Предметные рубрики: METAL-FILMS
RESISTIVITY
CONDUCTION
ELECTRONS
DENSITY
WOS
Найти похожие
9.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Kazak N. V., Bayukov O. A., Ovchinnikov S. G., Vasiliev A. D., Rudenko V. V., Ivanova N. B., Knyazev Yu. V., Bartolom J., Arauzo A.
Заглавие : The superexchange interactions in mixed Co-Fe ludwigite
Место публикации : J. Magn. Magn. Mater. - 2011. - Vol. 323, Is. 5. - P.521-527. - MAR. - ISSN 0304-8853, DOI 10.1016/j.jmmm.2010.09.057
Примечания : Cited Reference Count: 15. - Гранты: This 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), Physical Division of the Russian Academy of Science, the program "Strongly Correlated Electrons", project 2.3.1.; The financial support of Spanish MINCYT, MAT08/1077 and Aragonese E-34 project are also acknowledged.Финансирующая организация: Russian Foundation for Basic Research [09-02-00171-a]; Federal Agency for Science and Innovation (Rosnauka) [MK-5632. 2010.2]; Physical Division of the Russian Academy of Science; "Strongly Correlated Electrons" [2.3.1]; Spanish MINCYT [MAT08/1077]; Aragonese E-34 project
Предметные рубрики: TRANSPORT-PROPERTIES
SPECTRA
Ключевые слова (''Своб.индексиров.''): ludwigite structure--magnetic susceptibility--magnetic frustration--mott conductivity--ludwigite structure--magnetic frustration--magnetic susceptibility--mott conductivity--ac susceptibility--cation distributions--crystal data--crystallographic sites--electrical resistivity--iron atoms--low temperatures--ludwigite structure--magnetic behavior--magnetic frustrations--magnetic system--magnetic transitions--mossbauer--mossbauer effects--mott conductivity--mott hopping--superexchange energy--superexchange interaction--temperature regions--trivalent iron--variable range--cobalt--electric conductivity--magnetic susceptibility--magnetism--mossbauer spectroscopy--x ray diffraction--crystal structure
Аннотация: The crystal structure, cation distribution and exchange interactions in the Co2.25Fe0.75O2BO3 ludwigite have been explored through X-ray diffraction, electrical resistivity, ac-susceptibility and Mossbauer effect measurements. The crystal data have shown that iron atoms occupy the most symmetric crystallographic sites Fe4 and Fe2. The complex magnetic behavior with two magnetic transitions near 70 and 115 K at low temperatures was found. The Mossbauer data have displayed the trivalent iron states only. The values of superexchange energies have been estimated for Co3O2BO3 and Co2.25Fe0.75O2BO3 yielding a significant role of frustrations in the ludwigite magnetic system. Variable range Mott hopping conductivity law was proved to be valid in the wide temperature region, pointing out a localized character of charge carriers rather than collective. (C) 2010 Elsevier B.V. All rights reserved.
WOS,
Scopus,
eLibrary
Найти похожие
10.

Вид документа : Статья из сборника (однотомник)
Шифр издания :
Автор(ы) : Gokhfeld Yu. S., Solovyov L. A., Vereshchagin S. N., Borus A. A., Gudim I. A., Kazak N. V.
Заглавие : Thermal expansion and resistivity anomalies in Cu2FeBO5 ludwigite
Коллективы : Российская академия наук, Физико-технический институт им. Е.К. Завойского ФИЦ Казанского научного центра РАН, Казанский (Приволжский) федеральный университет, Euro-Asian Symposium "Trends in MAGnetism", "Trends in MAGnetism", Euro-Asian Symposium
Место публикации : VIII Euro-Asian symposium "Trends in magnetism" (EASTMAG-2022): Book of abstracts/ program com. S. G. Ovchinnikov [et al.]. - 2022. - Vol. 2, Sect. G: Frustrated and disordered magnetism. - Ст.G.P9. - P.27-28. - ISBN 978-5-94469-051-7
Примечания : Cited References: 5. - Support by RFBR 20-02-00559 and 21-52-12033 ННИО_а is acknowledged
Материалы симпозиума,
Читать в сети ИФ
Найти похожие
11.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Kazak N. V., Ivanova N. B., Rudenko V. V., Ovchinnikov S. G., Vasil'Ev A. D., Knyazev Yu. V.
Заглавие : Conductivity study of Co3O2BO3 and Co 3-xFexO2BO3 oxyborates
Коллективы : Moscow International Symposium on Magnetism
Место публикации : Solid State Phenomena. - 2009. - Vol. 152-153. - С. 104-107. - ISSN 10120394 (ISSN); 390845168X (ISBN); 9783908451686 (ISBN), DOI 10.4028/www.scientific.net/SSP.152-153.104
Ключевые слова (''Своб.индексиров.''): doped cobaltite--electrical conductivity--ludwigite--variable-range hopping--crystal structure--electric conductivity--magnetic materials--single crystals--crystal structure--electric conductivity--magnetic materials--magnetism--single crystals--electrical conductivity--electrical resistivity--experimental data--mott variable-range hopping--oxyborates--temperature regions--variable-range hopping--doped cobaltite--ludwigite--variable range hopping--cobalt--cobalt
Аннотация: Single crystals of cobalt oxyborates Co3O2BO 3 and Co3-xFexO2BO3 were synthesized. The crystal structure and electric properties were investigated. The difference in the electrical resistivity behaviors was found. For parent Co3O2BO3 nor simple activation law, nor Mott variable range hopping (VRH) are acquirable to describe the experimental data in wide temperature region. In contrast for Co3-xFex O 2BO3 Mott's variable-range hopping conductivity clearly dominates.
Scopus,
eLibrary,
WOS,
eLibrary
Найти похожие
12.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Korovushkin M. M.
Заглавие : Electrical resistivity and the Hall effect in the doped Mott-Hubbard material with strong spin-charge coupling
Колич.характеристики :14 с
Место публикации : Phys. Scr. - 2023. - Vol. 98, Is. 12. - Ст.125922. - ISSN 00318949 (ISSN), DOI 10.1088/1402-4896/ad05ed. - ISSN 14024896 (eISSN)
Примечания : Cited References: 96. - Author is grateful to V V Val’kov, A D Fedoseev, D M Dzebisashvili and M S Shustin for fruitful discussions and permanent interest in this work. Author thanks V A Mitskan and A O Zlotnikov for technical support
Аннотация: The kinetic characteristics of the doped Mott-Hubbard material are considered within the realistic spin-fermion model which takes into account the strong spin-charge coupling. The kinetic equation constructed on the basis of the mechanism of carrier scattering on the spin fluctuations is solved using the multi-moment method, which allows one to analyze the temperature behavior of nonequilibrium distribution function in the problems of electrical resistivity ρ and the Hall coefficient RH. The calculated dependences ρ(T) and RH(T) for the underdoped and optimally doped regimes demonstrate good qualitative agreement with the experimental data. In particular, the Hall coefficient calculated for the underdoped regime reproduces the experimentally observed sharp drop and even a change in sign at low temperatures.
Смотреть статью,
Scopus,
WOS
Найти похожие
13.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Drokin N. A., Kiiko V. S., Malkin A. I., Pavlov A. V.
Заглавие : Electrophysical properties of BeO + 30 wt.% TiO2 ceramics sintered at elevated temperatures
Место публикации : Refract. Ind. Ceram. - 2022. - Vol. 63, Is. 3. - P.315-320. - ISSN 1083-4877 (ISSN), DOI 10.1007/s11148-022-00728-3. - ISSN 1573-9139 (eISSN)
Примечания : Cited References: 11
Аннотация: The electrophysical properties of BeO-based ceramics with introduced micro- and nanoparticles of TiO2 were investigated by impedance spectroscopy in the frequency range of 100 Hz – 100 MHz. In order to increase the density and conductivity, the initial ceramic components were sintered at the highest possible temperatures up to 1660°C, followed by annealing in hydrogen at 800°C. In this case, TiO2 was strongly reduced with the formation of lower titanium oxides (Ti3O5) along with metallic titanium. When interacting with hydrogen, TiH2 is formed. For the first time, impurity phases were found in (BeO + TiO2) ceramics, which can significantly alter its bulk and surface properties. The resulting ceramics has a high reach-through conductivity, which increases significantly after an additional thermal annealing in hydrogen. It was established that the activation energy of conductivity does not depend much on the concentration of TiO2 nanoparticles and decreases significantly in the low-temperature region. The method of constructing equivalent electrical circuits was used to simulate the passage of the active and reactive components of the current through the complex internal structure of the ceramics.
Смотреть статью
Найти похожие
14.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Kagan M. Yu., Val'kov V. V.
Заглавие : Anomalous Resistivity and the Origin of Heavy Mass in the Two-Band Hubbard Model with One Narrow Band
Место публикации : J. Exp. Theor. Phys. - NEW YORK: PLEIADES PUBLISHING INC, 2011. - Vol. 113, Is. 1. - С. 156-171. - JUL. - ISSN 1063-7761, DOI 10.1134/S1063776111060021. - ISSN 1090-6509
Примечания : Cited Reference Count: 87. - RFBRRussian Foundation for Basic Research (RFBR) [08-02-00224, 08-02-00212]; Leverhulme trustLeverhulme Trust; CNRSCentre National de la Recherche Scientifique (CNRS)European Commission [236694], We are grateful to A. S. Alexandrov, A. F. Andreev, A. F. Barabanov, M. A. Baranov, Yu. Bychkov, A. V. Chubukov, D. V. Efremov, P. Fulde, A. S. Hewson, Yu. Kagan, K. A. Kikoin, K. I. Kugel, F. V. Kusmartsev, M. Mezard, Yu. E. Lozovik, P. Nozieres, N. V. Prokof'ev, A. L. Rakhmanov, T. M. Rice, A. O. Sboychakov, G. V. Shlyapnikov, P. Thalmeyer, C. M. Varma, D. Vollhardt, P. Woelfle, and A. Yaresko for the numerous simulating discussions on this subject and acknowledge financial support of the RFBR grants nos. 08-02-00224, 08-02-00212. M. Yu. K. is also grateful to Loughborough University (UK) and LPTMS (Orsay, France) for the hospitality during the final stage of this work and acknowledges financial support from the Leverhulme trust and CNRS (contract no. 236694).
Предметные рубрики: Physics, Multidisciplinary
Аннотация: We search for marginal Fermi-liquid behavior [1] in the two-band Hubbard model with one narrow band. We consider the limit of low electron densities in the bands and strong intraband and interband Hubbard interactions. We analyze the influence of electron polaron effect [2] and other mechanisms of mass enhancement (related to momentum dependence of the self-energies) on the effective mass and scattering times of light and heavy components in the clean case (electron-electron scattering and no impurities). We find the tendency towards phase separation (towards negative partial compressibility of heavy particles) in the 3D case for a large mismatch between the densities of heavy and light bands in the strong-coupling limit. We also observe that for low temperatures and equal densities, the homogeneous state resistivity R(T) similar to T-2 behaves in a Fermi-liquid fashion in both 3D and 2D cases. For temperatures higher than the effective bandwidth for heavy electrons T W-h*, the coherent behavior of the heavy component is totally destroyed. The heavy particles move diffusively in the surrounding of light particles. At the same time, the light particles scatter on the heavy ones as if on immobile (static) impurities. In this regime, the heavy component is marginal, while the light one is not. The resistivity saturates for T W-h* in the 3D case. In 2D, the resistivity has a maximum and a localization tail due to weak-localization corrections of the Altshuler-Aronov type [3]. Such behavior of resistivity could be relevant for some uranium-based heavy-fermion compounds like UNi2Al3 in 3D and for some other mixed-valence compounds possibly including layered manganites in 2D. We also briefly consider the superconductive (SC) instability in the model. The leading instability is towards the p-wave pairing and is governed by the enhanced Kohn-Luttinger [4] mechanism of SC at low electron density. The critical temperature corresponds to the pairing of heavy electrons via polarization of the light ones in 2D.
WOS
Найти похожие
15.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Yurkin G. Yu., Patrin G. S., Velikanov D. A., Beletsky V. V.
Заглавие : Transport properties of FeSi with cobalt impurities
Место публикации : TRENDS IN MAGNETISM. - 2011. - Vol. 168-169. - С. 493-496. - ISSN 10120394 (ISSN); 9783037850213 (ISBN), DOI 10.4028/www.scientific.net/SSP.168-169.493
Ключевые слова (''Своб.индексиров.''): iron monosilicide--kondo effect--magnetization--resistivity--spindependent scattering--superparamagnetic cluster--cobalt--crystals--electric resistance--electron energy loss spectroscopy--kondo effect--magnetic field effects--magnetic properties--magnetization--magnetoresistance--scattering--superparamagnetism--transport properties--cobalt--electric conductivity--electron scattering--impurities--kondo effect--magnetism--magnetization--experimental investigations--kondo models--magnetoresistance properties--resistivity--si crystals--spin dependent scattering--superparamagnetic clusters--crystal impurities--crystal impurities
Аннотация: The results of experimental investigations of Fe1-xCo xSi crystals in the impurity limit are presented in this article. We made an attempt to study changes of magnetic properties and conductivity in mixed Fe1-xCoxSi crystals in the impurity limit. Magnetoresistance properties are well described in the framework of Kondo model. The presence of Co-subsystem leads to the occurrence of spin-dependent channel in electron scattering conduction.
Scopus,
eLibrary,
WOS,
eLibrary
Найти похожие
16.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Shaikhutdinov K. A., Popkov S. I., Semenov S. V., Balaev D. A., Dubrovskiy A. A., Sablina K. A., Volkov N. V.
Заглавие : Low-temperature resistivity of polycrystalline (La0.5Eu 0.5)0.7Pb0.3MnO3 in a magnetic fields
Место публикации : J. Phys. Conf. Ser. - 2010. - Vol. 200, Is. SECTION 5. - ISSN 17426588 (ISSN) , DOI 10.1088/1742-6596/200/5/052025
Ключевые слова (''Своб.индексиров.''): antiferromagnetic grains--comparative analysis--ferromagnetic grain--low temperatures--polycrystalline--specific heat measurement--spin dependent tunneling--transport and magnetic properties--antiferromagnetism--electric resistance--europium--grain boundaries--grain size and shape--lanthanum compounds--lead--magnetic field effects--magnetic properties--magnetoresistance--manganese oxide--single crystals--thermal variables measurement--lanthanum
Аннотация: The effect of grain boundaries on magnetoresistance (MR) of manganites have been investigated by the comparative analysis of the properties of single-crystal and polycrystalline (La0.5Eu0.5) 0.7Pb0.3MnO3. While MR of the single crystal is maximum near the Curie temperature and vanishes in the low-temperature region, the polycrystalline (La0.5Eu0.5)0.7Pb 0.3MnO3 sample exhibits high MR in the low-temperature region. In order to clarify the origin of the low-temperature MR, the transport and magnetic properties of the polycrystalline (La0.5Eu 0.5)0.7Pb0.3MnO3 in magnetic fields have been supplemented by study of magnetic properties and specific heat measurements. The results obtained could be attributed to spin-dependent tunneling between ferromagnetic grains through insulating antiferromagnetic grain boundaries. © 2010 IOP Publishing Ltd.
Scopus,
eLibrary
Найти похожие
17.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Kagan M.Yu., Val'kov V. V.
Заглавие : Anomalous resistivity and the electron-polaron effect in the two- band Hubbard model with one narrow band
Место публикации : arXiv. - 2011. - Ст.1111.3135
Найти похожие
18.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Gavrichkov V. A., Ovchinnikov S. G., Nekrasov I. A., Pchelkina Z. V.
Заглавие : Electronic Structure of p-Type La1-xMx2+MnO3 Manganites in the Ferromagnetic and Paramagnetic Phases in the LDA plus GTB Approach
Разночтения заглавия :авие SCOPUS: Electronic structure of p-Type La 1-x M x 2+ MnO 3 manganites in the ferromagnetic and paramagnetic phases in the LDA + GTB approach
Место публикации : J. Exp. Theor. Phys.: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2011. - Vol. 112, Is. 5. - P860-876. - ISSN 1063-7761, DOI 10.1134/S1063776111030101
Примечания : Cited References: 47. - This study was supported financially by integration project no. 40 of the Ural and Siberian Branches of the Russian Academy of Sciences, the program "Strong Electron Correlations" of the Russian Academy of Sciences, and the Russian Foundation for Basic Research (project no. 10-02-00251-a).
Предметные рубрики: DOUBLE-EXCHANGE
COLOSSAL MAGNETORESISTANCE
THIN-FILMS
PHYSICS
LA1-XSRXMNO3
RESISTIVITY
SEPARATION
TRANSPORT
MODEL
Ключевые слова (''Своб.индексиров.''): complex structure--cubic materials--ferromagnetic phase--half metals--jahn teller effect--metal properties--metal types--orbitals--p-type--paramagnetic phase--paramagnetic phasis--quasi particles--spectral intensity--spin projections--strong electron correlations--barium--density functional theory--electron correlations--electron density measurement--electronic properties--electronic structure--fermi level--ferromagnetic materials--ferromagnetism--manganese oxide--manganites--paramagnetic materials--paramagnetism--valence bands--lanthanum
Аннотация: The band structure, spectral intensity, and position of the Fermi level in doped p-type La1-xMx2+ MnO3 manganites (M = Sr, Ca, Ba) is analyzed using the LDA + GBT method for calculating the electronic structure of systems with strong electron correlations, taking into account antiferro-orbital ordering and using the Kugel-Khomskii ideas and real spin S = 2. The results of the ferromagnetic phase reproduce the state of a spin half-metal with 100% spin polarization at T = 0, when the spectrum is of the metal type for a quasiparticle with one spin projection and of the dielectric type for the other. It is found that the valence band becomes approximately three times narrower upon a transition to the paramagnetic phase. For the paramagnetic phase, metal properties are observed because the Fermi level is located in the valence band for any nonzero x. The dielectrization effect at the Curie temperature is possible and must be accompanied by filling of d(x) orbitals upon doping. The effect itself is associated with strong electron correlations, and a complex structure of the top of the valence band is due to the Jahn-Teller effect in cubic materials. DOI: 10.1134/S1063776111030101
WOS,
Scopus,
РИНЦ,
Смотреть статью,
Читать в сети ИФ
Найти похожие
19.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Neznakhin D. S., Samoshkina Yu. E., Molokeev M. S., Semenov S. V.
Заглавие : Structural, electrical and magnetic study of manganites Pr0.6Sr0.4MnO3 thin films
Коллективы : Russian Youth Conference on Physics of Semiconductors and Nanostructures, Opto- and Nanoelectronics
Место публикации : J. Phys. Conf. Ser./ Russian Youth Conference on Physics of Semiconductors and Nanostructures, Opto- and Nanoelectronics (17 ; 23 - 27 Nov. 2015): IOP Publishing, 2016. - Vol. 690, Is. 1. - ISSN 17426588 (ISSN), DOI 10.1088/1742-6596/690/1/012002
Примечания : Cited References: 20. - The work was supported partly by RFBR, grant №14-02-01211, Grant of President of Russian Federation №NSh-2886.2014.2, and by The Ministry of Education and Science of the Russian Federation, project №2582.
Ключевые слова (''Своб.индексиров.''): magnetic materials--magnetization--manganese oxide--nanoelectronics--nanostructures--oxide films--field dependence--magnetization temperature curves--polycrystalline phase--polycrystalline pr--resistivity dependence--shape characteristics--structural parameter--zero-field cooling--thin films
Аннотация: Thin polycrystalline Pr0.6Sr0.4MnO3 films were grown on the Y stabilized zirconium oxide substrates by magnetron sputtering using RF power and off-axis sputtering scheme with double cathodes. Only one polycrystalline phase with structural parameters consistent with that for the corresponding bulk sample was revealed in the films. Electric resistivity dependence on temperature demonstrates the shape characteristic for the substances with the Mott transition. The difference between magnetization temperature curves measured in the zero field cooling and field cooling modes was revealed. Magnetization field dependences were presented by the hysteresis loops changing their form with temperature. © Published under licence by IOP Publishing Ltd.
Смотреть статью,
Scopus,
Читать в сети ИФ
Найти похожие
20.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Shaykhutdinov K. A., Popkov S. I., Semenov S. V., Balaev D. A., Dubrovskiy A. A., Sablina K. A., Sapronova N. V., Volkov N. V.
Заглавие : Low-temperature resistance and magnetoresistance hysteresis in polycrystalline (La0.5Eu0.5)(0.7)Pb0.3MnO3
Разночтения заглавия :авие SCOPUS: Low-temperature resistance and magnetoresistance hysteresis in polycrystalline (La0.5Eu0.5)0.7Pb 0.3MnO3
Место публикации : J. Appl. Phys.: AMER INST PHYSICS, 2011. - Vol. 109, Is. 5. - Ст.53711. - ISSN 0021-8979, DOI 10.1063/1.3559303
Примечания : Cited References: 20. - This study was partially supported by the Russian Foundation for Basic Research, Project No. 08-02-00259a and the Lavrentyev Competition of the Young Scientists' Projects of the Siberian Branch of the Russian Academy of Sciences, Project No. 12.
Предметные рубрики: RESISTIVITY MINIMUM
MANGANITES
FILMS
Ключевые слова (''Своб.индексиров.''): antiferromagnets--electrical resistances--ferromagnets--field dependence--inter-grain--lanthanum manganites--low temperatures--low-temperature resistance--polycrystalline--temperature dependence--tunnel contacts--antiferromagnetic materials--europium--ferromagnetic materials--ferromagnetism--hysteresis--lead--magnetic field effects--magnetoelectronics--magnetoresistance--magnets--manganese oxide--paramagnetism--superconducting materials--electric resistance
Аннотация: The behavior of temperature dependences of electrical resistance and magnetoresistance of polycrystalline substituted lanthanum manganite (La0.5Eu0.5)(0.7)Pb0.3MnO3 at low temperatures was thoroughly studied. A broad hysteresis was found in the field dependences of electrical resistance in the low-temperature region. Above 40 K, no hysteresis feature was observed. The temperature T = 40 K corresponds to the temperature of minimum electrical resistance and the temperature T-N to the antiferromagnet-paramagnet phase transition of the material of the intergrain boundaries. In this work we propose a model which explains the observed features of the rho(T) and rho(H) curves at temperatures below T-N by the formation of a network of ferromagnet-antiferromagnet-ferromagnet tunnel contacts. (C) 2011 American Institute of Physics. [doi:10.1063/1.3559303]
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
 

Другие библиотеки

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