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:
полныйинформационныйкраткий
Отсортировать найденные документы по:
авторузаглавиюгоду изданиятипу документа
Поисковый запрос: (<.>K=Resistivity<.>)
Общее количество найденных документов : 34
Показаны документы с 1 по 10
 1-10    11-20   21-30   31-34 
1.


    Kagan, M. Y.
    Anomalous resistivity and the electron-polaron effect in the two-band hubbard model with one narrow band / M. Y. Kagan, V. V. Val'kov // J. Supercond. Nov. Magn. - 2012. - Vol. 25, Is. 5. - P. 1379-1382, DOI 10.1007/s10948-012-1523-3. - Cited References: 28. - We are grateful to P. Fulde, Yu. Kagan, K. I. Kugel, N.V. Prokof'ev, P. Nozieres, and C. M. Varma for the numerous stimulating discussions. We acknowledge financial support of the RFBR Grant No. 11-02-00741. . - ISSN 1557-1939
РУБ Physics, Applied + Physics, Condensed Matter
Рубрики:
FERMI GAS
   SUPERCONDUCTIVITY

   SUPERFLUIDITY

   TEMPERATURE

   REPULSION

   SYSTEMS

Кл.слова (ненормированные):
Electron-polaron effect -- Two-band Hubbard model -- Marginality -- Anomalous resistivity
Аннотация: We search for anomalous normal and superconductive behavior in the two-band Hubbard model with one narrow band. We analyze the influence of the electron–polaron effect and the Altshuler–Aronov effect on effective mass enhancement and scattering times of heavy and light components in the clean case. We find anomalous behavior of resistivity at high temperatures T>W∗hT > W_{h}^{*} both in 3D and 2D situations. The SC instability in the model is governed by an enhanced Kohn–Luttinger effect for p-wave pairing of heavy electrons via polarization of light electrons.

Смотреть статью,
Scopus,
WoS,
Читать в сети ИФ
Держатели документа:
[Kagan, M. Y.] PL Kapitza Inst Phys Problems, Moscow 119334, Russia
[Val'kov, V. V.] Kirenskii Inst Phys, Krasnoyarsk 660036, Russia
P.L. Kapitza Institute for Physical Problems, Kosygina st. 2, 119334 Moscow, Russian Federation
Kirenskii Institute of Physics, Akademgorodok 50, Building 38, 660036 Krasnoyarsk, Russian Federation

Доп.точки доступа:
Val'kov, V. V.; Вальков, Валерий Владимирович; Каган, Максим Юрьевич
}
Найти похожие
2.


   
    Electrical and dielectrical propeties of gas-sensor resistive type Bi2Sn2O7 / L. V. Udod [et al.] // Solid State Phenom. : Selected, peer reviewed papers. - 2014. - Vol. 215: Trends in Magnetism: Nanomagnetism (EASTMAG-2013). - P. 503-506, DOI 10.4028/www.scientific.net/SSP.215.503. - Cited References: 14. - This work was supported by the Russian Foundation for Basic Research projects no. 12-02-00125-а . - ISSN 978-30383. - ISSN 1662-9779
   Перевод заглавия: Электрические и диэлектрические свойства резистивного типа газовых сенсоров на основе Bi2Sn2O7
Кл.слова (ненормированные):
crystallographic structure -- polymorphic transformations -- electrical resistivity -- dielectric permeability
Аннотация: Polycrystalline samples of Bi2Sn2O7 have been synthesized by conventional solid-state reaction method. According to the X-ray powder diffraction research, our sample co-existing of two polymorphs phases: cubic and rhombic, concurrently. The real dielectric permeability Re (ε) monotonic grows versus temperature and the imaginary dielectric permeability Im (ε) nonmonotonic is increased at the heating. There are maxima at Т=450 K on both temperature dependences Im (ε) and Re (ε) reveal. Anomalies in the temperature dependence of electrical resistivity at temperatures are found and to be correlated with the α → β structural phase transition temperature.

Читать в сети ИФ

Доп.точки доступа:
Ovchinnikov, S. G. \ed.\; Овчинников, Сергей Геннадьевич; Samardak, A. \ed.\; Udod, L. V.; Удод, Любовь Викторовна; Sitnicov, M. N.; Aplesnin, S. S.; Аплеснин, Сергей Степанович; Molokeev, M. S.; Молокеев, Максим Сергеевич; Euro-Asian Symposium "Trends in MAGnetism": Nanomagnetism(5 ; 2013 ; sept. ; 15-21 ; Vladivostok)
}
Найти похожие
3.


   
    Effect of Mn doping on magnetic and dielectric properties of Bi2Sn2O7 / L. V. Udod [et al.] // Solid State Phenom. : Selected, peer reviewed papers. - 2015. - Vol. 233-234: Achievements in Magnetism. - P. 105-108, DOI 10.4028/www.scientific.net/SSP.233-234.105 . - ISSN 1662-9779. - ISSN 978-3-038
Рубрики:
Achievements in magnetism
Кл.слова (ненормированные):
crystallographic structure -- cubic phase -- dielectric permeability -- electrical resistivity -- magnetic moment -- martensitic phase transitions -- orthorhombic phases -- polymorphic transformation
Аннотация: The Bi2(Sn0.95Mn0.05)2O7 compound existing simultaneously in two polymorphic modifications, namely, orthorhombic and cubic has been synthesized for the first time by solid-phase synthesis. The magnetic, dielectric and electrical properties of the compound have been studied. Anomalies in the temperature dependences of the electrical resistance and magnetic propoties have been found. These features are explained as martensitic phase transitions.

Смотреть статью,
Материалы конференции,
Scopus,
Читать в сети ИФ

Доп.точки доступа:
Perov, N. \ed.\; Semisalova, A. \ed.\; Udod, L. V.; Удод, Любовь Викторовна; Aplesnin, S. S.; Аплеснин, Сергей Степанович; Sitnikov, M. N.; Eremin, E. V.; Еремин, Евгений Владимирович; Molokeev, M. S.; Молокеев, Максим Сергеевич; Moscow International Symposium on Magnetism(6 ; 2014 ; June-July ; Moscow)
}
Найти похожие
4.


    Удод, Любовь Викторовна.
    Влияние катионного замещения на полиморфные переходы в пирасаннате висмута Bi2Sn2O7 / Л. В. Удод, М. Н. Ситников // Вестник СибГАУ. - 2015. - Т. 16, № 4. - С. 975-982. - Библиогр.: 53. - Работа выполнена при финансовой поддержке Российского фонда фундаментальных исследований, грант № 15-42-04099 р_сибирь_а, и государственного задания № 114090470016 . - ISSN 1816-9724
Кл.слова (ненормированные):
полиморфные переходы -- диэлектрическая проницаемость -- электросопротивление -- катионное замещение -- дифференциальная сканирующая калориметрия -- polymorphic transitions -- dielectric permeability -- cation substitution -- electrical resistivity -- differential scanning calorimetry
Аннотация: Рассмотрена разработка технологии новых сенсорных материалов, необходимых для газочувствительных приборов, применяемых в ракетостроении. Целью данной работы является изучение влияния допирования разновалентными катионами на кристаллографическую структуру, диэлектрические и электрические свойства пирохлорного соединения Bi 2Sn 2O 7, обладающего селективной избирательностью к газам. Методом твердофазного синтеза впервые синтезированы соединения Bi2(Sn1-xMex)2O7, где Me = Mn, Cr, x = 0, 0,05, находящиеся сразу в двух полиморфных модификациях - орторомбической и кубической. В твердых растворах Bi2(Sn0,95Cr0,05)2O 7 методом сканирующей калориметрии обнаружено два новых структурных перехода, по сравнению со станнатом висмута Bi2Sn2O7. Ионы Mn 4+ сместили фазовые границы полиморфных переходов в сторону меньших температур, а фазовый α→β-переход около 370 К, характерный для Bi2(Sn1-xCrx)2O7, где x = 0, 0,05, подавили почти полностью. Полиморфный переход при Т = 543 К для Bi 2(Sn0,95Mn0,05) 2O 7 протекает с выделением тепла, в отличие от Bi2(Sn1-xCrx)2O7, где x = 0, 0,05. Исследована взаимосвязь структурных, электрических и диэлектрических свойств. Установлены аномалии в температурной зависимости электросопротивления и диэлектрической проницаемости (мнимой и реальной частями) как в области низких температур, так и при высоких температурах. Эти особенности объясняются в рамках модели мартенситных фазовых переходов. Методом сканирующей калориметрии найдены температуры структурных фазовых переходов, которые коррелируют с аномалиями электросопротивления в интервале температур 300 < T < 1000 К для Bi2(Sn1-xCrx)2O7, x = 0, 0,05.
The goal of this work is to develop a new technology of sensor materials required for gas sensing devices used in missile. The aim of this work is to study the effect of doping cations with different valency on the crystallographic structure, dielectric and electrical properties of pyrochlore compound Bi2Sn2O7 with selectivity to gases. Polycrystalline compounds Bi2(Sn1-xMex)2O7, where Me = Mn, Cr, x = 0, 0.05 have been synthesized by conventional solid-state reaction. According to the X-ray powder diffraction research, our sample consists of two polymorphs phases: cubic and rhombic. Two new structural transition are found in Bi2(Sn0.95Cr0.05)2O7 solid solutions by scanning calorimetry, as compared to bismuth pyrostannate Bi2Sn2O7. Ions Mn 4+ leads to shift of phase boundary of polymorphic transitions towards lower temperatures, and the phase α→β-transition at about 370 K, which is characteristic for Bi2(Sn1-xCrx)2O7, where x = 0, 0.05 is suppressed. The polymorphic transition at T = 543 K for Bi2(Sn0.95Mn0.05)2O7 occurs with calorification, in contrast to Bi2(Sn1-xCrx)2 7, where x = 0, 0.05. The relationship between structural, electrical and dielectric properties is investigated. Anomalies in the temperature dependence of electrical resistivity and dielectric permeability (real and imaginary part) as in the low region temperatures as in the high region temperature are found. These features are explained within a model of martensitic phase transitions. The temperature of the structural phase transitions correlates with temperature of maximum of the electrical resistivity in the temperature range 300 < T < 1000 K for Bi2(Sn1-xCrx)2O7, x = 0, 0.05 was found by scanning calorimetry method.

РИНЦ,
Читать в сети ИФ
Держатели документа:
Институт физики им. Л.В. Киренского СО РАН

Доп.точки доступа:
Ситников, Максим Николаевич; Sitnikov, M.N.; Udod, L. V.
}
Найти похожие
5.


   
    Structural, electrical and magnetic study of manganites Pr0.6Sr0.4MnO3 thin films / D. S. Neznakhin [et al.] // J. Phys. Conf. Ser. - 2016. - Vol. 690, Is. 1, DOI 10.1088/1742-6596/690/1/012002. - 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. . - ISSN 1742-6588
   Перевод заглавия: Структурные, электрические и магнитные исследования тонких пленок манганита Pr0.6Sr0.4MnO3
Кл.слова (ненормированные):
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

Доп.точки доступа:
Neznakhin, D. S.; Samoshkina, Yu. E.; Самошкина, Юлия Эрнестовна; Molokeev, M. S.; Молокеев, Максим Сергеевич; Semenov, S. V.; Семёнов, Сергей Васильевич; Russian Youth Conference on Physics of Semiconductors and Nanostructures, Opto- and Nanoelectronics(St. Petersburg)(17 ; 23 - 27 Nov. 2015)
}
Найти похожие
6.


   
    Electronic Structure of p-Type La1-xMx2+MnO3 Manganites in the Ferromagnetic and Paramagnetic Phases in the LDA plus GTB Approach / V. A. Gavrichkov [et al.] // J. Exp. Theor. Phys. - 2011. - Vol. 112, Is. 5. - P. 860-876, DOI 10.1134/S1063776111030101. - 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). . - ISSN 1063-7761
РУБ Physics, Multidisciplinary
Рубрики:
DOUBLE-EXCHANGE
   COLOSSAL MAGNETORESISTANCE

   THIN-FILMS

   PHYSICS

   LA1-XSRXMNO3

   RESISTIVITY

   SEPARATION

   TRANSPORT

   MODEL

Кл.слова (ненормированные):
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

Публикация на русском языке Электронная структура манганитов La[1-x]M[x]2+MnO[3] p-типа в ферромагнитной и парамагнитной фазах в рамках LDA+GTB-подхода [Текст] / В. А. Гавричков [и др.] // Журнал экспериментальной и теоретической физики. - 2011. - Т. 139 Вып. 5. - С. 983-1000

Держатели документа:
[Gavrichkov, V. A.
Ovchinnikov, S. G.] Russian Acad Sci, Siberian Branch, LV Kirensky Phys Inst, Krasnoyarsk 660036, Russia
[Gavrichkov, V. A.
Ovchinnikov, S. G.] Siberian Fed Univ, Krasnoyarsk 660041, Russia
[Nekrasov, I. A.] Russian Acad Sci, Ural Branch, Inst Electrophys, Ekaterinburg 620016, Russia
[Pchelkina, Z. V.] Russian Acad Sci, Ural Branch, Inst Met Phys, Ekaterinburg 620990, Russia
ИФ СО РАН
Siberian Branch, Kirensky Institute of Physics, Russian Academy of Sciences, Krasnoyarsk, 660036, Russian Federation
Siberian Federal University, Krasnoyarsk, 660041, Russian Federation
Ural Branch, Institute of Electrophysics, Russian Academy of Sciences, Yekaterinburg, 620016, Russian Federation
Ural Branch, Institute of Metal Physics, Russian Academy of Sciences, Yekaterinburg, 620990, Russian Federation

Доп.точки доступа:
Gavrichkov, V. A.; Гавричков, Владимир Александрович; Ovchinnikov, S. G.; Овчинников, Сергей Геннадьевич; Nekrasov, I. A.; Pchelkina, Z. V.
}
Найти похожие
7.


   
    Magnetoresistance of substituted lanthanum manganites La0.7Ca0.3MnO3 upon nonequilibrium overheating of carriers / K. A. Shaykhutdinov [et al.] // J. Appl. Phys. - 2011. - Vol. 109, Is. 8. - Ст. 83711, DOI 10.1063/1.3573666. - Cited References: 15. - This study was partially supported by the Russian Foundation for Basic Research, project no. 08-02-00259a, and the Lavrent'ev's Competition of Young Scientists of the Siberian Branch of the RAS, project no. 12. . - ISSN 0021-8979
РУБ Physics, Applied

Кл.слова (ненормированные):
Field dependence -- Lanthanum manganites -- Low thermal conductivity -- Manganite materials -- Negative differential resistivity -- Non equilibrium -- Non-Linearity -- Nonequilibrium heating -- Polycrystalline -- Positive magnetoresistance -- Transport currents -- Electric resistance -- Electron gas -- Heating -- Lanthanum -- Lanthanum alloys -- Magnetic fields -- Magnetoelectronics -- Magnetoresistance -- Manganese oxide -- Manganites -- Thermal conductivity -- Current voltage characteristics
Аннотация: Current-voltage characteristics of the polycrystalline substituted lanthanum manganite La0.7Ca0.3MnO3 were experimentally studied at T - 77.4 K in magnetic fields up to 13 kOe. In these characteristics, a portion of negative differential resistivity was observed above a certain threshold value of critical current density j caused, in our opinion, by nonequilibrium heating of the electron gas due to low thermal conductivity of the manganite material. Because of the nonlinearity of the current-voltage characteristics, the field dependences of resistivity rho( H) appear extremely sensitive to the value of a transport current. In this case, the rho( H) dependences reveal both ordinary negative and positive magnetoresistance. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3573666]

WOS,
Scopus,
Читать в сети ИФ
Держатели документа:
[Shaykhutdinov, K. A.
Semenov, S. V.
Popkov, S. I.
Balaev, D. A.
Bykov, A. A.
Dubrovskiy, A. A.
Petrov, M. I.
Volkov, N. V.] Russian Acad Sci, LV Kirensky Phys Inst, Siberian Branch, Krasnoyarsk 660036, Russia
[Shaykhutdinov, K. A.
Popkov, S. I.
Balaev, D. A.
Dubrovskiy, A. A.
Volkov, N. V.] Siberian Fed Univ, Krasnoyarsk 660041, Russia
ИФ СО РАН
Kirensky Institute of Physics, Russian Academy of Sciences, Siberian Branch, Krasnoyarsk, 660036, Russian Federation
Siberian Federal University, Krasnoyarsk, 660041, Russian Federation

Доп.точки доступа:
Shaykhutdinov, K. A.; Шайхутдинов, Кирилл Александрович; Semenov, S. V.; Семенов, Сергей Васильевич; Popkov, S. I.; Попков, Сергей Иванович; Balaev, D. A.; Балаев, Дмитрий Александрович; Bykov, A. A.; Быков, Алексей Анатольевич; Dubrovskiy, A. A.; Дубровский, Андрей Александрович; Petrov, M. I.; Петров, Михаил Иванович; Volkov, N. V.; Волков, Никита Валентинович
}
Найти похожие
8.


   
    Low-temperature resistance and magnetoresistance hysteresis in polycrystalline (La0.5Eu0.5)(0.7)Pb0.3MnO3 / K. A. Shaykhutdinov [et al.] // J. Appl. Phys. - 2011. - Vol. 109, Is. 5. - Ст. 53711, DOI 10.1063/1.3559303. - 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. . - ISSN 0021-8979
РУБ Physics, Applied
Рубрики:
RESISTIVITY MINIMUM
   MANGANITES

   FILMS

Кл.слова (ненормированные):
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
Держатели документа:
[Shaykhutdinov, K. A.
Popkov, S. I.
Semenov, S. V.
Balaev, D. A.
Dubrovskiy, A. A.
Sablina, K. A.
Sapronova, N. V.
Volkov, N. V.] Russian Acad Sci, LV Kirensky Phys Inst, Siberian Branch, Krasnoyarsk 660036, Russia
[Shaykhutdinov, K. A.
Balaev, D. A.
Dubrovskiy, A. A.
Volkov, N. V.] Siberian Fed Univ, Krasnoyarsk 660041, Russia
ИФ СО РАН
Kirensky Institute of Physics, Russian Academy of Sciences, Siberian Branch, Krasnoyarsk 660036, Russian Federation
Siberian Federal University, Krasnoyarsk 660041, Russian Federation

Доп.точки доступа:
Shaykhutdinov, K. A.; Шайхутдинов, Кирилл Александрович; Popkov, S. I.; Попков, Сергей Иванович; Semenov, S. V.; Семенов, Сергей Васильевич; Balaev, D. A.; Балаев, Дмитрий Александрович; Dubrovskiy, A. A.; Дубровский, Андрей Александрович; Sablina, K. A.; Саблина, Клара Александровна; Sapronova, N. V.; Volkov, N. V.; Волков, Никита Валентинович
}
Найти похожие
9.


    Kagan, M. Y.
    Anomalous resistivity and superconductivity in the two-band Hubbard model with one narrow band (Review) / M. Y. Kagan, V. V. Valkov // Low Temp. Phys. - 2011. - Vol. 37, Is. 1. - P. 69-82 ; Физика низких температур, DOI 10.1063/1.3552118. - Cited References: 62. - We thank A.S. Alexandrov, A.F. Andreev, M.A. Baranov, Yu. Bichkov, A.V. Chubukov, D.V. Efremov, A.S. Hewson, K.A. Kikoin, F.V. Kusmartsev, P. Nozieres, T.M. Rice, A.O. Sboychakov, P. Thalmeer, C.M. Varma, D. Vollhardt, P. Woelfle, A. Yaresko and, especially, P. Fulde, Yu. Kagan, K.I. Kugel, and N.V. Prokof'ev for many simulating discussions on this subject and acknowledge the financial support of RFBR grants # 08-02-00224 and 08-02-00212. M.Yu.K. is also grateful to the Leverhulme trust for a grant to visit Loughborough University, where this work was completed. . - ISSN 1063-777X
РУБ Physics, Applied
Рубрики:
FERMI-LIQUID BEHAVIOR
   MAGNETIC-ALLOYS

   HEAVY

   DENSITY

   SYSTEMS

   STATE

   UPT3

   MECHANISM

   PARTICLE

   VALENCE

Аннотация: We search for marginal Fermi-liquid behavior 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 effects and other mechanisms for mass-enhancement (related to the 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 a tendency towards phase separation (towards negative partial compressibility of heavy particles) in the 3D case with a large mismatch between the densities of heavy and light bands in the strong coupling limit. We also find that for low temperatures and equal densities, the resistivity in a homogeneous state R(T) proportional to T-2 behaves as a Fermi-liquid in both 3D and 2D. For temperatures greater than the effective bandwidth for heavy electrons T W-h*, the coherence of the heavy component breaks down completely. The heavy particles move diffusively in the surrounding light particles. At the same time, light particles scatter on heavy particles as if on immobile (static) impurities. Under these conditions, the heavy component is marginal, while the light component is not. The resistivity approaches saturation for T W-h* in the 3D case. In 2D the resistivity has a maximum and a localization tail owing to weak-localization corrections of the Altshuler-Aronov type. This behavior of resistivity in 3D could be relevant for some uranium-based heavy-fermion compounds such as UNi2Al3 and in 2D, for some other mixed-valence compounds, possibly including layered manganites. We also consider briefly the superconductive (SC) instability in this model. The leading instability tends to p-wave pairing and is governed by an enhanced Kohn-Luttinger mechanism for SC at low electron densities. The critical temperature corresponds to the pairing of heavy electrons via polarization of the light electrons in 2D. (C) 2011 American Institute of Physics. [doi:10.1063/1.3552118]

WOS,
Scopus,
Читать в сети ИФ
Держатели документа:
[Kagan, M. Yu.] Russian Acad Sci, PL Kapitza Phys Problems Inst, Moscow 119334, Russia
[Valkov, V. V.] Russian Acad Sci, LV Kirensky Phys Inst, Siberian Branch, Krasnoyarsk 660036, Russia
ИФ СО РАН
P.L.Kapitza Institute for Physical Problems of the Russian Academy of Sciences, 2 Kosygin St., Moscow 119334, Russian Federation
Kirensky Institute of Physics, Siberian Branch of the Russian Academy of Sciences, Akademgorodok, Krasnoyarsk 660036, Russian Federation

Доп.точки доступа:
Valkov, V. V.; Вальков, Валерий Владимирович

}
Найти похожие
10.


   
    Dielectric properties of a mixed-valence Pb3Mn7O15 manganese oxide / N. V. Volkov [et al.] // J. Phys.: Condens. Matter. - 2010. - Vol. 22, Is. 37. - Ст. 375901, DOI 10.1088/0953-8984/22/37/375901. - Cited References: 14. - This study was supported by the Russian Foundation for Basic Research 'Siberia', project No. 09-02-98003, and the Siberian Branch of the Russian Academy of Sciences, integration project No. 101. . - ISSN 0953-8984
РУБ Physics, Condensed Matter

Кл.слова (ненормированные):
cation -- lead -- manganese derivative -- oxide -- article -- chemical model -- chemistry -- crystallization -- electric conductivity -- electronics -- methodology -- temperature -- Cations -- Crystallization -- Electric Conductivity -- Electronics -- Lead -- Manganese Compounds -- Models, Chemical -- Oxides -- Temperature -- AC electric field -- Analysis of resistivity -- Carrier hopping -- Charge ordering -- Complex dielectric constant -- Crystal site -- Debye models -- Dielectric constants -- Dielectric spectra -- Frequency windows -- Lattice sites -- Low frequency -- Manganese ions -- Mixed valence -- Mixed valence state -- Relaxation behaviors -- Temperature range -- Electric fields -- Manganese -- Manganese oxide -- Permittivity -- Single crystals -- Crystal symmetry
Аннотация: We investigated the low-frequency dielectric properties of a Pb3Mn7O15 single crystal with manganese ions in the mixed-valence state (Mn3+/Mn4+). Dielectric relaxation was found in the frequency window from 20 to 100 kHz in the temperature range 110-180 K. The dielectric spectra of the crystal were analyzed using a Debye model. Estimations made within the model and analysis of resistivity data suggest that the relaxation behavior of the dielectric constant is related to polaronic charge carrier hopping. Around 250 K, charge ordering occurs in the crystal when the Mn3+ and Mn4+ ions are arranged in a specific order among the crystal sites. With a decrease in temperature, an ac electric field can induce a charge hop between the equivalent lattice sites available, related to crystal symmetry. This hopping is equivalent to the reorientation of an electric dipole that yields Debye-type behavior of the complex dielectric constant. The observed anisotropy in the behavior of the dielectric properties and resistivity can be attributed to a pronounced two-dimensional character of the crystal structure.

WOS,
Scopus,
Scopus,
Читать в сети ИФ
Держатели документа:
[Volkov, N. V.
Eremin, E. V.
Sablina, K. A.
Sapronova, N. V.] Russian Acad Sci, LV Kirensky Phys Inst, Siberian Branch, Krasnoyarsk 660036, Russia
ИФ СО РАН
L V Kirensky Institute of Physics, Russian Academy of Sciences, Siberian Branch, Krasnoyarsk, Russia.
L V Kirensky Institute of Physics, Russian Academy of Sciences, Siberian Branch, Krasnoyarsk 660036, Russian Federation

Доп.точки доступа:
Volkov, N. V.; Волков, Никита Валентинович; Eremin, E. V.; Еремин, Евгений Владимирович; Sablina, K. A.; Саблина, Клара Александровна; Sapronova, N. V.
}
Найти похожие
 1-10    11-20   21-30   31-34 
 

Другие библиотеки

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