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1.


    Drokin, N. A.
    Static and dynamic characteristics of the bulk and contact electric resistivity in CDCR2SE4 under stochastic current instability / N. A. Drokin, S. M. Ganiev // Fiz. Tverd. Tela. - 1992. - Vol. 34, Is. 7. - P. 2122-2128. - Cited References: 21 . - ISSN 0367-3294
РУБ Physics, Condensed Matter
Рубрики:
OSCILLATIONS
   CHAOS

   GE


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Доп.точки доступа:
Ganiev, S. M.; Дрокин, Николай Александрович
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2.


   
    Study of electroconductivity in cobalt nanocrystalline films / G. I. Frolov [и др.] // Fiz. Tverd. Tela. - 1996. - Vol. 38, Is. 4. - P. 1208-1213. - Cited References: 13 . - ISSN 0367-3294
РУБ Physics, Condensed Matter
Рубрики:
METAL-FILMS
   RESISTIVITY

   CONDUCTION

   ELECTRONS

   DENSITY


WOS

Доп.точки доступа:
Frolov, G. I.; Zhigalov, V. S.; Polskii, A. I.; Pozdnyakov, V. G.
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3.


    Gavrichkov, V. A.
    An impurity resistivity of doped manganese perovskites / V. A. Gavrichkov, S. G. Ovchinnikov // Physica B. - 1999. - Vol. 259-61: International Conference on Strongly Correlated Electron Systems (SCES 98) (JUL 15-18, 1998, PARIS, FRANCE). - P. 828-830, DOI 10.1016/S0921-4526(98)00875-8. - Cited References: 4 . - ISSN 0921-4526
РУБ Physics, Condensed Matter
Рубрики:

Кл.слова (ненормированные):
manganese perovskites -- mobility -- linear and quadratic magnetoresistance
Аннотация: We present a two-time of relaxation approach at an analysis of a magnetoresistance in ferromagnetic manganese perovskites La(1-x)(Ca,Sr)(x)MnO. To explain a change in the low-held response from predominantly quadratic dR/dH\(H-->0) = 0 for T > T(c) to linear dR/dH\(H-->0) for T < T(c) as noted in the measurements in thin films La(0.7)Ca(0.3)MnO(3) we calculated held and temperature dependences of a impurity contribution to a carrier mobility in a framework of the 2p(O)- and 3d(Mn)-scattering model elaborated for manganese perovskites. We obtained the field-dependent impurity contribution to the overall scattering of carriers that show a transition in the low-field (H) dependence of R from quadratic above T(c) to linear below consistent with an experiment. The calculated negative magnetoresistance ratio is sharply peaked at a temperature-near T(c) or below. (C) 1999 Elsevier Science B.V. All rights reserved.

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Держатели документа:
Inst Phys, Krasnoyarsk 660036, Russia
ИФ СО РАН
Institute of Physics, 660036 Krasnoyarsk, Russian Federation

Доп.точки доступа:
Ovchinnikov, S. G.; Овчинников, Сергей Геннадьевич; Гавричков, Владимир Александрович
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4.


    Gavrichkov, V. A.
    Characteristic features of the extrinsic electric resistance in ferromagnets with low carrier density / V. A. Gavrichkov, S. G. Ovchinnikov // Phys. Solid State. - 1999. - Vol. 41, Is. 1. - P. 59-66, DOI 10.1134/1.1130731. - Cited References: 26 . - ISSN 1063-7834
РУБ Physics, Condensed Matter
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].

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Публикация на русском языке Гавричков, Владимир Александрович. Особенности примесного электросопротивления в ферромагнетиках с малой концентрацией носителей [Текст] / В. А. Гавричков, С. Г. Овчинников // Физ. тверд. тела. - С.-Петербург, 1999. - Т. 41 Вып. 1. - С. 68-76

Держатели документа:
Russian Acad Sci, LV Kirensky Phys Inst, Siberian Branch, Krasnoyarsk 660036, Russia
ИФ СО РАН

Доп.точки доступа:
Ovchinnikov, S. G.; Овчинников, Сергей Геннадьевич; Гавричков, Владимир Александрович
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5.


    Erkaev, N. V.
    Reconnection rate for the inhomogeneous resistivity Petschek model / N. V. Erkaev, V. S. Semenov, F. . Jamitzky // Phys. Rev. Lett. - 2000. - Vol. 84, Is. 7. - P. 1455-1458, DOI 10.1103/PhysRevLett.84.1455. - Cited References: 16 . - ISSN 0031-9007
РУБ Physics, Multidisciplinary
Рубрики:
MAGNETIC RECONNECTION
   CURRENT SHEETS

Аннотация: The reconnection rate for the canonical simplest case of steady-state two-dimensional symmetric reconnection in an incompressible plasma is found by matching of an outer Petschek solution and an internal diffusion region solution. The reconnection rate obtained naturally incorporates both Sweet-Parker and Petschek regimes; while the latter is possible only for a strongly localized resistivity.

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Держатели документа:
Russian Acad Sci, Inst Computat Modelling, Krasnoyarsk 660036, Russia
St Petersburg State Univ, Inst Phys, St Petersburg 198904, Russia
Max Planck Inst Extraterr Phys, D-85740 Garching, Germany
ИВМ СО РАН

Доп.точки доступа:
Semenov, V. S.; Jamitzky, F.; Еркаев, Николай Васильевич
}
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6.


    Zakharov, Y. V.
    Negative magnetoresistance of iron single-crystal whiskers in the course of magnetization reversal / Y. V. Zakharov, L. S. Titov // Phys. Solid State. - 2004. - Vol. 46, Is. 2. - P. 303-305, DOI 10.1134/1.1649428. - Cited References: 9 . - ISSN 1063-7834
РУБ Physics, Condensed Matter
Рубрики:
RESISTIVITY
   WALLS

Аннотация: The change in the low-temperature resistance of iron single-crystal whiskers during magnetization reversal form a single-domain state to a state with a plane-parallel domain structure is studied theoretically. The negative magnetoresistance (similar to45%) is calculated from the Kubo formula with due regard for the change in the trajectories of conduction electrons in a magnetic induction field of domains. The magnetoresistance thus calculated is of the same order of magnitude as the magnetoresistance obtained in the experiment performed by Isin and Coleman.(C) 2004 MAIK "Nauka / Interperiodica".

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Держатели документа:
Russian Acad Sci, LV Kirensky Phys Inst, Siberian Div, Krasnoyarsk 660036, Russia
Krasnoyarsk State Univ, Krasnoyarsk 660062, Russia
ИФ СО РАН
Kirensky Institute of Physics, Siberian Division, Russian Academy of Sciences, Akademgorodok, Krasnoyarsk 660036, Russian Federation
Krasnoyarsk State University, Svobodnyi pr. 79, Krasnoyarsk 660062, Russian Federation

Доп.точки доступа:
Titov, L. S.
}
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7.


   
    Influence of magnetic ordering on the resistivity anisotropy of alpha-MnS single crystal / S. S. Aplesnin [et al.] // Solid State Commun. - 2004. - Vol. 129, Is. 3. - P. 195-197 ; Solid State Commun. - 2004. - Vol. 129, Is. 3. - P. 195-197, DOI 10.1016/j.ssc.2003.09.028. - Cited References: 7 . - ISSN 0038-1098. - Вариант Sopus
РУБ Physics, Condensed Matter

Кл.слова (ненормированные):
anisotropy of resistivity -- optical gap -- D. Anisotropy of resistivity -- D. Optical gap -- Antiferromagnetism -- Band structure -- Bandwidth -- Diffractometers -- Electron transitions -- Fermi level -- Hamiltonians -- Light absorption -- Magnetic anisotropy -- Magnetization -- Single crystals -- Spectroscopic analysis -- X ray diffraction analysis -- Coulomb repulsion -- Resistivity anisotropy -- Semiconducting manganese compounds -- D. Anisotropy of resistivity -- D. Optical gap -- Antiferromagnetism -- Band structure -- Bandwidth -- Diffractometers -- Electron transitions -- Fermi level -- Hamiltonians -- Light absorption -- Magnetic anisotropy -- Magnetization -- Single crystals -- Spectroscopic analysis -- X ray diffraction analysis -- Coulomb repulsion -- Resistivity anisotropy -- Semiconducting manganese compounds
Аннотация: The resistivity and the optical absorbtion spectra of single crystal alpha-MnS are studied in the temperature range 80-300 K along two directions [100] and [111]. Strong anisotropy of the resistivity, and the shift of absorbtion spectra band edge below T < 160 K are explained in terms of model involving delocalized holes in 3d-band manganese ions interacting with localized spins by using the sd-model. (C) 2003 Elsevier Ltd. All rights reserved.

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Держатели документа:
Russian Acad Sci, LV Kirensky Phys Inst, Siberian Branch, Krasnoyarsk 660036, Russia
ИФ СО РАН
Siberian Branch, Academcumpus, Russian Academy of Sciences, 660036 Krasnoyarsk, Russian Federation
Siberian Branch, Academcumpus, Russian Academy of Sciences, 660036 Krasnoyarsk, Russian Federation

Доп.точки доступа:
Aplesnin, S. S.; Аплеснин, Сергей Степанович; Petrakovskii, G. A.; Петраковский, Герман Антонович; Ryabinkina, L. I.; Рябинкина, Людмила Ивановна; Abramova, G. M.; Абрамова, Галина Михайловна; Kiselev, N. I.; Romanova, O. B.; Романова, Оксана Борисовна

}
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8.


   
    Mossbauer magnetization and resistivity studies of Fe1.91V0.09BO4 / N. V. Kazak [et al.] // Physica B. - 2005. - Vol. 359: International Conference on Strongly Correlated Electron Systems (SCES 04) (JUL 26-30, 2004, Karlsruhe, GERMANY). - P. 1324-1326, DOI 10.1016/j.physb.2005.01.396. - Cited References: 8 . - ISSN 0921-4526
РУБ Physics, Condensed Matter
Рубрики:
FE2OBO3
Кл.слова (ненормированные):
Mott-hubbard system -- magnetism -- new materials -- Magnetism -- Mott-hubbard system -- New materials -- Crystallization -- Crystallography -- Fermi level -- Ferrimagnetism -- Magnetism -- Magnetization -- Mossbauer spectroscopy -- Phase transitions -- Single crystals -- X ray diffraction analysis -- Charge ordering -- Electron-electron interactions -- Mott-hubbard system -- New materials -- Iron compounds
Аннотация: Single crystals of Fe1.91V0.09BO4 were prepared by spontaneous crystallization using a solution melt technology for the first time and its structure, electronic and magnetic properties were investigated by X-ray diffraction, Mossbauer spectroscopy, magnetization and electrical measurements. Room-temperature Mossbauer measurements indicate that "localized" (Fe2+, Fe3+) and "delocalized" (Fe2.5+) states in ratio 0.31:0.345:0.345 distributed over two crystallographically non-equivalent positions exist. The results of magnetic measurements show that warwickite is a P-type ferrimagnet below T = 130 K. Resistivity measurements show a variable-range-hopping when electron-electron interactions cause a soft Coulomb gap in the density of states at the Fermi energy. (c) 2005 Elsevier B.V. All rights reserved.

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Держатели документа:
Russian Acad Sci, Siberian Branch, LV Kirensky Phys Inst, Krasnoyarsk 660036, Russia
Krasnoyarsk State Tech Univ, Krasnoyarsk 660074, Russia
ИФ СО РАН
LV Kirensky Institute of Physics, Siberian Branch of RAS, 660036 Krasnoyarsk, Russian Federation
Krasnoyarsk State Tech. University, 660074 Krasnoyarsk, Russian Federation

Доп.точки доступа:
Kazak, N. V.; Казак, Наталья Валерьевна; Balaev, A. D.; Балаев, Александр Дмитриевич; Ivanova, N. B.; Иванова, Наталья Борисовна; Ovchinnikov, S. G.; Овчинников, Сергей Геннадьевич
}
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9.


   
    Hysteretic behavior of the magnetoresistance and the critical current of bulk Y3/4Lu1/4Ba2CU3O7+CuOcomposites in a magnetic field / D. A. Balaev [et al.] // Physica C. - 2007. - Vol. 460: 8th International Conference on Materials and Mechanisms of Superconductivity and High Temperature Superconductors (JUL 09-14, 2006, Dresden, GERMANY). - P. 1307-1308, DOI 10.1016/j.physc.2007.03.346. - Cited References: 7 . - ISSN 0921-4534
РУБ Physics, Applied
Рубрики:
SUPERCONDUCTORS
Кл.слова (ненормированные):
HTSC -- resistivity -- magnetic field -- relaxation -- HTSC -- Magnetic field -- Relaxation -- Resistivity -- Crystallites -- Magnetic fields -- Magnetic hysteresis -- Magnetoresistance -- Yttrium barium copper oxides -- Superconducting crystallites -- Superconducting systems -- Tunnel-type Josephson junctions -- Josephson junction devices
Аннотация: The hysteretic behavior of critical current j(C)(H) and magneto-resistance R(H) of composites Y-Ba-Cu-O + CuO have been studied and presented. The composites represent the network of tunnel-type Josephson junctions where copper oxide acts as a material forming barriers between superconducting (YBCO) crystallites. The characteristic features of R(H) and j(C)(H) dependences are discussed in the frames of the conception of "two level superconducting system" (the Josephson media and HTSC crystallites) which is realized in the composites under study. (c) 2007 Elsevier B.V. All rights reserved.

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Держатели документа:
LV Kirenskii Inst Phys, Krasnoyarsk 660036, Russia
ИФ СО РАН
Kirensky Institute of Physics, Krasnoyarsk, 660036, Russian Federation

Доп.точки доступа:
Balaev, D. A.; Балаев, Дмитрий Александрович; Gokhfeld, D. M.; Гохфельд, Денис Михайлович; Popkov, S. I.; Попков, Сергей Иванович; Shaykhutdinov, K. A.; Шайхутдинов, Кирилл Александрович; Petrov, M. I.; Петров, Михаил Иванович
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10.


   
    Conductivity study of Co3O2BO3 and Co 3-xFexO2BO3 oxyborates / N. V. Kazak [et al.] // Solid State Phenomena. - 2009. - Vol. 152-153. - P104-107, DOI 10.4028/www.scientific.net/SSP.152-153.104 . - ISSN 1012-0394
Кл.слова (ненормированные):
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.

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Держатели документа:
L.V. Kirensky Institute of Physics, SB of RAS, 660036, Akademgorodok, Krasnoyarsk, Russian Federation
Politechnical Institute, Siberian Federal University, Kirensky str. 26, 660074 Krasnoyarsk, Russian Federation

Доп.точки доступа:
Kazak, N. V.; Казак, Наталья Валерьевна; Ivanova, N. B.; Иванова, Наталья Борисовна; Rudenko, V. V.; Руденко, Валерий Васильевич; Ovchinnikov, S. G.; Овчинников, Сергей Геннадьевич; Vasil'Ev, A. D.; Васильев, Александр Дмитриевич; Knyazev, Yu. V.; Князев, Юрий Владимирович; Moscow International Symposium on Magnetism(4 ; 2008 ; Jun. ; Moscow)
}
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11.


   
    Peculiarity of interrelation between electronic and magnetic properties of HTSC cuprates associated with short-range antiferromagnetic order / S. G. Ovchinnikov [et al.] // J. Exp. Theor. Phys. - 2010. - Vol. 111, Is. 1. - P. 104-113, DOI 10.1134/S1063776110070101. - Cited References: 48. - This study was financially supported by the Russian Foundation for Basic Research (project nos. 09-02-01224 and 09-02-00127) and under the program "Quantum Physics of Condensed Media" of the Presidium of the Russian Academy of Sciences (project no. 5.7). . - ISSN 1063-7761
РУБ Physics, Multidisciplinary
Рубрики:
T-J MODEL
   NORMAL-STATE

   FERMI-SURFACE

   RESISTIVITY ANISOTROPY

   3-CENTER INTERACTIONS

   OPTICAL CONDUCTIVITY

   COPPER OXIDES

   CUO2 PLANES

   SUPERCONDUCTORS

   TRANSPORT

Кл.слова (ненормированные):
Anisotropic resistivity -- Antiferromagnetic orders -- Concentration dependence -- Cuprates -- Doping levels -- Electronic and magnetic properties -- Fermi surface topology -- High temperature superconducting -- Magnetic orders -- Magnetic state -- Maximum values -- Pseudo-gap -- Short-range magnetic orders -- Strong electron correlations -- Temperature dependence -- Anisotropy -- Antiferromagnetic materials -- Antiferromagnetism -- Copper compounds -- Correlators -- Electronic properties -- High temperature superconductors -- Hole concentration -- Magnetic properties -- Neon -- Superconducting magnets -- Single crystals
Аннотация: We report on the results of measurements of anisotropic resistivity of RBa(2)Cu(3)O(6 + x) (R = Tm, Lu) high-temperature superconducting single crystals in a wide range of doping levels, indicating a nontrivial effect of magnetic order on the electronic properties of cuprates. In particular, our results visually demonstrate the crossover from the state with moderate anisotropy of resistivity rho (c) /rho (ab) similar to 30 to a strongly anisotropic state with rho (c) /rho (ab) similar to 7 x 10(3) upon cooling as well as upon a decrease in the hole concentration in the CuO(2) planes. It is also shown that anisotropy is sensitive to the magnetic state of CuO(2) planes and attains its maximum value after the establishment of the long-range antiferromagnetic order. The results are discussed in the framework of the theory based on the t-t'-taEuro(3)-J model of CuO(2) layers taking into account strong electron correlations and short-range magnetic order. In this theory, anomalies of spin correlators and Fermi surface topology for a critical hole concentration of p* a parts per thousand 0.24 are demonstrated. The concentration dependence of the charge carrier energy indicates partial suppression of energy due to the emergence of a pseudogap at p < p*. This theory explains both the experimentally observed sensitivity of anisotropy in conductivity to the establishment of the antiferromagnetic order and the absence of anomalies in the temperature dependence of resistivity rho (ab) (T) in the vicinity of the N,el temperature.

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Публикация на русском языке Особенность взаимосвязи электронных и магнитных свойств ВТСП-купратов, обусловленная ближним антиферромагнитным порядком [Текст] / С. Г. Овчинников [и др.] // Журн. эксперим. и теор. физ. - 2010. - Т. 138 Вып. 1.- P.115-125

Держатели документа:
[Ovchinnikov, S. G.
Korshunov, M. M.] Russian Acad Sci, Kirenskii Inst Phys, Siberian Branch, Krasnoyarsk 660036, Russia
[Ovchinnikov, S. G.] Siberian Fed Univ, Krasnoyarsk 660041, Russia
[Korshunov, M. M.] Univ Florida, Dept Phys, Gainesville, FL 32611 USA
[Kozeeva, L. P.
Lavrov, A. N.] Russian Acad Sci, Nikolaev Inst Inorgan Chem, Siberian Branch, Novosibirsk 630090, Russia
ИФ СО РАН
Kirenskii Institute of Physics, Siberian Branch, Russian Academy of Sciences, Krasnoyarsk 660036, Russian Federation
Siberian Federal University, Krasnoyarsk 660041, Russian Federation
Department of Physics, University of Florida, Gainesville, FL 32611, United States
Nikolaev Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090, Russian Federation

Доп.точки доступа:
Ovchinnikov, S. G.; Овчинников, Сергей Геннадьевич; Korshunov, M. M.; Коршунов, Максим Михайлович; Kozeeva, L. P.; Lavrov, A. N.; Лавров, Александр Николаевич
}
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12.


   
    Low-temperature resistivity of polycrystalline (La0.5Eu 0.5)0.7Pb0.3MnO3 in a magnetic fields / K. A. Shaykhutdinov [et al.] // J. Phys. Conf. Ser. - 2010. - Vol. 200, Is. SECTION 5, DOI 10.1088/1742-6596/200/5/052025 . - ISSN 1742-6588
Кл.слова (ненормированные):
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.

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Держатели документа:
Kirensky Institute of Physics, Russian Academy of Sciences, Siberian Branch, Krasnoyarsk, 660036, Russian Federation
Siberian Federal University, Krasnoyarsk, 660041, Russian Federation

Доп.точки доступа:
Shaikhutdinov, K. A.; Шайхутдинов, Кирилл Александрович; Popkov, S. I.; Попков, Сергей Иванович; Semenov, S. V.; Balaev, D. A.; Балаев, Дмитрий Александрович; Dubrovskiy, A. A.; Дубровский, Андрей Александрович; Sablina, K. A.; Саблина, Клара Александровна; Volkov, N. V.; Волков, Никита Валентинович
}
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13.


   
    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.

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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.
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14.


   
    Anomalous resistivity and the electron-polaron effect in the two- band Hubbard model with one narrow band / Kagan M.Yu., Val'kov V.V. // arXiv. - 2011. - Ст. 1111.3135


Доп.точки доступа:
Kagan, M.Yu.; Val'kov, V. V.; Вальков, Валерий Владимирович
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15.


   
    The superexchange interactions in mixed Co-Fe ludwigite / N. V. Kazak [et al.] // J. Magn. Magn. Mater. - 2011. - Vol. 323, Is. 5. - P. 521-527, DOI 10.1016/j.jmmm.2010.09.057. - 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 . - MAR. - ISSN 0304-8853
Рубрики:
TRANSPORT-PROPERTIES
   SPECTRA

Кл.слова (ненормированные):
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.

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Держатели документа:
RAS, LV Kirensky Phys Inst, SB, Krasnoyarsk 660036, Russia
Siberian Fed Univ, Krasnoyarsk 660074, Russia
Krasnoyarsk State Agr Univ, Krasnoyarsk 660049, Russia
Univ Zaragoza, CSIC, Inst Ciencia Mat Aragon, Abd Dept Fis Mat Condensada, E-50009 Zaragoza, Spain
Univ Zaragoza, Area Medidas Fis, Serv Instrumentac Cient, E-50009 Zaragoza, Spain

Доп.точки доступа:
Kazak, N. V.; Казак, Наталья Валерьевна; Bayukov, O. A.; Баюков, Олег Артемьевич; Ovchinnikov, S. G.; Овчинников, Сергей Геннадьевич; Vasiliev, A. D.; Васильев, Александр Дмитриевич; Rudenko, V. V.; Руденко, Валерий Васильевич; Ivanova, N. B.; Иванова, Наталья Борисовна; Knyazev, Yu. V.; Князев, Юрий Владимирович; Bartolom, J.; Arauzo, A.
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16.


   
    Transport properties of FeSi with cobalt impurities / G. Y. Yurkin [et al.] // TRENDS IN MAGNETISM. - 2011. - Vol. 168-169. - P493-496, DOI 10.4028/www.scientific.net/SSP.168-169.493 . - ISSN 1012-0394
Кл.слова (ненормированные):
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.

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Держатели документа:
Kirensky Institute of Physics, SB, RAS, 660036, Krasnoyarsk, Russian Federation
Siberian Federal University, 660041, Krasnoyarsk, Russian Federation

Доп.точки доступа:
Yurkin, G. Yu.; Юркин, Глеб Юрьевич; Patrin, G. S.; Патрин, Геннадий Семёнович; Velikanov, D. A.; Великанов, Дмитрий Анатольевич; Beletsky, V. V.
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17.


   
    Anomalous Resistivity and the Origin of Heavy Mass in the Two-Band Hubbard Model with One Narrow Band / M. Yu. Kagan, V. V. Val'kov // J. Exp. Theor. Phys. - 2011. - Vol. 113, Is. 1. - P156-171, DOI 10.1134/S1063776111060021. - 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). . - JUL. - ISSN 1063-7761. - ISSN 1090-6509
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.

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Держатели документа:
Kapitza Inst Phys Problems, Moscow 119334, Russia;
Kirenskii Inst Phys, Krasnoyarsk 660036, Russia

Доп.точки доступа:
Kagan, M. Yu.; Val'kov, V. V.; Вальков, Валерий Владимирович
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18.


    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]

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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

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19.


   
    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]

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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
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20.


   
    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

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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.
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