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1.


    Dzebisashvili, D. M.
    Fermi surface evolution in the ensemble of spin-polarized quasiparticles in La2 - xSrxCuO4 / D. M. Dzebisashvili, V. V. Val'kov, A. F. Barabanov // JETP Letters. - 2014. - Vol. 98, Is. 9. - P. 528-533, DOI 10.1134/S0021364013220049. - Cited References: 36. - This work was supported by the Presidium of the Russian Academy of Sciences (program "Quantum Mesoscopic and Disordered Structures"), by the Russian Foundation for Basic Research (project nos. 13-02-00909, 13-02-00523, and 11-02-98007-Siberia), and by the Dynasty Foundation. . - ISSN 0021-3640. - ISSN 1090-6487
РУБ Physics, Multidisciplinary
Рубрики:
SADDLE-POINT SINGULARITY
   ANTIFERROMAGNETIC CORRELATIONS

   CUPRATE SUPERCONDUCTORS

   NORMAL-STATE

   MODEL

   BI2SR2CACU2O8+DELTA

   YBA2CU3O6.9

   LA2CUO4

   EXCITATIONS

   YBA2CU4O8

Аннотация: For the spin-fermion model, it has been shown that the concept of spin polarons makes it possible to reproduce fine details of the Fermi surface evolution in the nodal direction of La2-xSrxCuO4 occurring with changes in the doping level x. The physics here is determined by the spin-correlated hopping of charge carriers and by the doping dependence of the inverse magnetic correlation length. © 2013 Pleiades Publishing, Inc.

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Публикация на русском языке Дзебисашвили, Дмитрий Михайлович. Эволюция ферми-поверхности ансамбля спин-поляронных квазичастиц в La2−xSrxCuO4 [Текст] / Д. М. Дзебисашвили, В. В. Вальков, А. Ф. Барабанов // Письма в Журн. эксперим. и теор. физ. : Наука, 2013. - Т. 98 Вып. 9. - С. 596-601

Держатели документа:
Russian Acad Sci, Kirensky Inst Phys, Siberian Branch, Krasnoyarsk 660036, Russia
Siberian State Aerosp Univ, Krasnoyarsk 660014, Russia
Russian Acad Sci, Inst High Pressure Phys, Troitsk 142092, Moscow Region, Russia

Доп.точки доступа:
Val'kov, V. V.; Вальков, Валерий Владимирович; Barabanov, A. F.; Дзебисашвили, Дмитрий Михайлович
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2.


    Val'kov, V. V.
    Effect of the concentration-dependent spin-charge correlations on the evolution of the energy structure of the 2D Emery model / V. V. Val'kov, D. M. Dzebisashvili, A. F. Barabanov // J. Exp. Theor. Phys. - 2014. - Vol. 118, Is. 6. - P. 959-970, DOI 10.1134/S1063776114060223. - Cited References: 48. - This work was supported by the program "Quantum Physics of Mesoscopic and Disordered Systems" of the Presidium of the Russian Academy of Sciences, the Russian Foundation for Basic Research (project nos. 13-02-00909, 13-02-00523, and 13-02-98013_r-sibir), and the Dynasty foundation. . - ISSN 1063-7761. - ISSN 1090-6509
РУБ Physics, Multidisciplinary
Рубрики:
SADDLE-POINT SINGULARITY
   CUPRATE SUPERCONDUCTORS

   FERMI-SURFACE

   ANTIFERROMAGNETIC CORRELATIONS

   NORMAL-STATE

   Bi2Sr2CaCu2O8+δ

   EXCITATIONS

   YBa2Cu3O6.9

   La2CuO4

   YBa2Cu4O8

Аннотация: It is shown using the 2D Emery model that the strong coupling between the spin subsystem of copper ions in the singlet state and the subsystem of oxygen holes considerably reduces the spectral intensity of the correlation function for holes on the Fermi contour. Spin-charge correlations are manifested in the existence of two channels. The first channel is due to the p-d exchange coupling of spins of the oxygen and copper holes. The second channel appears as a result of spin-correlated hoppings, when the motion of holes over oxygen ions is accompanied by spin-flip processes (i.e., simultaneous changes in the spin projections of an oxygen hole and a copper ion). It is established as a result of self-consistent calculations that the allowance for the concentration dependence of spin correlators and multicenter spin-charge correlators appearing in the dispersion equation ensures a decrease in the energy of the system and considerably affects the evolution of the Fermi surface under hole doping.

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Публикация на русском языке Вальков, Валерий Владимирович. Влияние концентрационно-зависимых спин-зарядовых корреляций на эволюцию энергетической структуры двумерной модели Эмери [Текст] / В. В. Вальков, Д. М. Дзебисашвили, А. Ф. Барабанов // Ж. эксперим. и теор. физ. : Наука, 2014. - Т. 145 Вып. 6. - С. 1087-1100

Держатели документа:
Russian Acad Sci, LV Kirensky Phys Inst, Siberian Branch, Krasnoyarsk 660036, Russia
Siberian State Aerosp Univ, Krasnoyarsk 660014, Russia
Russian Acad Sci, Inst High Pressure Phys, Moscow 142190, Russia

Доп.точки доступа:
Dzebisashvili, D. M.; Дзебисашвили, Дмитрий Михайлович; Barabanov, A. F.; Барабанов А. Ф.; Вальков, Валерий Владимирович; Presidium of the Russian Academy of Sciences; Russian Foundation for Basic Research [13-02-00909, 13-02-00523, 13-02-98013_r-sibir]; Dynasty foundation
}
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3.


   
    Coupling of Hubbard fermions with phonons in La2 CuO4: A combined study using density-functional theory and the generalized tight-binding method / E. I. Shneyder [et al.] // J. Alloys Compd. - 2015. - Vol. 648. - P. 258-264, DOI 10.1016/j.jallcom.2015.05.150. - Cited References: 60. - We acknowledge the stimulating discussions with V.V. Val'kov, D.M. Dzebisashvilly, M.M. Korshunov and I.S. Sandalov. E.I.S. and S.G.O. are thankful to the Russian Science Foundation (project No. 14-12-00061) for the support of the research given in Sections 2, 6 and 7. E.E.K. and I.A.N. are thankful to the State Contract No. 0389-2014-0001 and RFBR grant No. 14-02-00065 for the support of the research given in Section 5. Financial support of the research given in Sections 3 and 4 by the Austrian Federal Government (in particular from Bundesministerium fur Verkehr, Innovation und Technologie and Bundesministerium fur Wissenschaft, Forschung und Wirtschaft) represented by Osterreichische Forschungsforderungsgesellschaft mbH and the Styrian and the Tyrolean Provincial Government, represented by Steirische Wirtschaftsforderungsgesellschaft mbH and Standortagentur Tirol, within the framework of the COMET Funding Programme is gratefully acknowledged by C.D. and J.S. . - ISSN 0925-8388
РУБ Chemistry, Physical + Materials Science, Multidisciplinary + Metallurgy & Metallurgical Engineering
Рубрики:
MEAN-FIELD THEORY
   LINEAR-RESPONSE THEORY

   CUPRATE SUPERCONDUCTORS

   ELECTRONIC-STRUCTURE

   CORRELATED SYSTEMS

   LATTICE-DYNAMICS

   BAND-STRUCTURE

   LA2CUO4

   MODEL

   LA2-XSRXCUO4

Кл.слова (ненормированные):
High-temperature superconductivity -- Electron-phonon coupling -- Density-functional theory -- Generalized tight-binding approach
Аннотация: We present results for the electron-phonon interaction of the Γ-point phonons in the tetragonal high-temperature phase of La2 CuO4 obtained from a hybrid scheme, combining density-functional theory (DFT) with the generalized tight-binding approach. As a starting point, eigenfrequencies and eigenvectors for the Γ-point phonons are determined from DFT within the frozen phonon approach utilizing the augmented plane wave + local orbitals method. The so obtained characteristics of electron-phonon coupling are converted into parameters of the generalized tight-binding method. This approach is a version of cluster perturbation theory and takes the strong on-site electron correlations into account. The obtained parameters describe the interaction of phonons with Hubbard fermions which form quasiparticle bands in strongly correlated electron systems. As a result, it is found that the Γ-point phonons with the strongest electron-phonon interaction are the A2u modes (236 cm-1, 131 cm-1 and 476 cm-1). Finally it is shown, that the single-electron spectral-weight redistribution between different Hubbard fermion quasiparticles results in a suppression of electron-phonon interaction which is strongest for the triplet Hubbard band with z oriented copper and oxygen electrons. © 2015 Elsevier B.V. All rights reserved.

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Держатели документа:
Kirensky Institute of Physics SB RAS, Akademgorodok 50, Bld. 38, Krasnoyarsk, Russian Federation
Reshetnev Siberian State Aerospace University, Krasnoyarsk, Russian Federation
Materials Center Leoben Forschung GmbH, Rosegger-Stra?e 18, Leoben, Austria
Institute of Electrophysics UB RAS, Amundsena Str. 106, Yekaterinburg, Russian Federation
Physics Department and IRIS Adlershof, Humboldt-Universita¨t zu Berlin, Zum Großen Windkanal 6, Berlin, Germany

Доп.точки доступа:
Shneyder, E. I.; Шнейдер, Елена Игоревна; Spitaler, J.; Kokorina, E. E.; Nekrasov, I. A.; Gavrichkov, V. A.; Гавричков, Владимир Александрович; Draxl, C.; Ovchinnikov, S. G.; Овчинников, Сергей Геннадьевич
}
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4.


   
    Electronic transitions and genuine crystal-field parameters in copper metaborate CuB2O4 / R. V. Pisarev [et al.] // Phys. Rev. B. - 2011. - Vol. 84, Is. 7. - Ст. 75160, DOI 10.1103/PhysRevB.84.075160. - Cited References: 65. - Useful discussions with W. Weber on crystal-field splitting of 3d states in cuprates are appreciated. We thank H.-J. Weber for the help in using Cary 2300 spectrophotometer. This work is supported by the Russian Foundation for Basic Research (project No. 09-02-00070) and Federal Agency for Science and Innovations (Grant No. 02.740.11.0384). A. M. K. acknowledges the financial support from the Committee for Science and Higher Education of the Government of Saint Petersburg. . - ISSN 1098-0121
РУБ Physics, Condensed Matter
Рубрики:
OPTICAL-ABSORPTION
   PHASE-DIAGRAM

   CUGEO3

   SPECTRUM

   SUPERCONDUCTORS

   EXCITATIONS

   SR2CUO2CL2

   SCATTERING

   LA2CUO4

   CUPRATE

Аннотация: We present and analyze high-resolution alpha-, sigma-, and pi-polarized absorption spectra related to d-d electronic transitions in tetragonal metaborate CuB2O4 where copper Cu2+ ions occupy two crystallographically distinct 4b and 8d positions. The spectra are characterized by exceptionally rich fine structure in the spectral range of 1.4-2.4 eV. Six zero-phonon (ZP) lines originating from the electronic transitions within the Cu2+ ions in both positions are distinguished and identified. Symmetry analysis explains polarization properties of the ZP lines in the 8d positions but only partially explains them in the 4b positions. Reliable assignment of all six ZP lines to specific transitions allowed us to calculate genuine cubic Dq and tetragonal Ds and Dt crystal-field parameters for both positions. We show that the (3r(2) - z(2)) state, the energy of which is the measure of the Jahn-Teller splitting, is the highest 3d state for both types of Cu2+ ion positions. Using the obtained crystal-field parameters as the reference values, we estimated Dq, Ds, and Dt for several other cuprates with different Cu-O bond lengths. In particular, the 3d level splitting in La2CuO4, Nd2CuO4, CuGeO3, Sr2CuO2Cl2, and Cu3B7O13Cl was analyzed. Our estimates suggest that the Jahn-Teller splitting in some of these cuprates is larger than it was assumed previously.

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Держатели документа:
[Pisarev, R. V.
Kalashnikova, A. M.] Russian Acad Sci, AF Ioffe Phys Tech Inst, St Petersburg 194021, Russia
[Schoeps, O.] Dortmund Tech Univ, Inst Phys, D-44221 Dortmund, Germany
[Bezmaternykh, L. N.] Russian Acad Sci, Siberian Branch, Inst Phys, Krasnoyarsk 660036, Russia
ИФ СО РАН
Ioffe Physical-Technical Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russian Federation
Institute of Physics, Dortmund Technical University, 44221 Dortmund, Germany
Institute of Physics, Siberian Branch, Russian Academy of Sciences, 660036 Krasnoyarsk, Russian Federation

Доп.точки доступа:
Pisarev, R. V.; Kalashnikova, A. M.; Schops, O.; Bezmaternykh, L. N.; Безматерных, Леонард Николаевич
}
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5.


    Aplesnin, S. S.
    Quantum Monte Carlo investigation of the 2D Heisenberg model with S=1/2 / S. S. Aplesnin // Phys. Solid State. - 1999. - Vol. 41, Is. 1. - P. 103-107, DOI 10.1134/1.1130737. - Cited References: 33 . - ISSN 1063-7834
РУБ Physics, Condensed Matter
Рубрики:
SQUARE-LATTICE
   GROUND-STATE

   SPIN-CORRELATIONS

   ANTIFERROMAGNET

   LA2CUO4

   EU2CUO4

   ENERGY

   ORDER

Аннотация: The two-dimensional (2D) Heisenberg model with anisotropic exchange (Delta=1-J(x)/J(z)) and S=1/2 is investigated by the quantum Monte Carlo method. The energy, susceptibility, specific heat, spin-spin correlation functions, and correlation radius are calculated. The sublattice magnetization (sigma) and the Neel temperature of the anisotropic antiferromagnet are logarithmic functions of the exchange anisotropy: 1/sigma + 1 + 0.13(1) ln(1/Delta). Crossover of the static magnetic structural factor as a function of temperature from power-law to exponential occurs for T(c)/J approximate to 0.4. The correlation radius can be approximated by 1/xi =2.05T(1.0(6))/exp(1.0(4)/ T). For La(2)CuO(4) the sublattice magnetization is calculated as sigma=0.45, the exchange is J=(1125=1305) K; for Er(2)CuO(4)J similar to 625 K and the exchange anisotropy Delta similar to 0.003. The temperature dependence of the static structural magnetic factor and the correlation radius above the Neel temperature in these compounds can be explained by the formation of topological excitations (spinons). (C) 1999 American Institute of Physics. [S1063-7834(99)02401-6].

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

Доп.точки доступа:
Аплеснин, Сергей Степанович
}
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6.


    Aplesnin, S. S.
    A study of anisotropic Heisenberg antiferromagnet with S=1/2 on a square lattice by Monte-Carlo method / S. S. Aplesnin // Phys. Status Solidi B. - 1998. - Vol. 207, Is. 2. - P. 491-498, DOI 10.1002/(SICI)1521-3951(199806)207:2491::AID-PSSB4913.0.CO;2-G. - Cited References: 24 . - ISSN 0370-1972
РУБ Physics, Condensed Matter
Рубрики:
EU2CUO4
   LA2CUO4

   ORDER

   MODEL

   STATE

Аннотация: The two-dimensional (2D) Heisenberg model (J 0) with anisotropic exchange Delta = 1-J(X)/J(Z) greater than or equal to 0 and with S = 1/2 is studied by the quantum Monte-Carlo method. Energy, susceptibility, specific heat, spin-spin correlation functions, and correlation radius are calculated. The dependence of the Neel temperature T(N)/J = 2/ln(11/Delta) on the exchange anisotropy is determined. The static magnetic factor is very slowly decreased for T/J 0.4. It is assumed to realize topological excitations in the range of these temperatures. The correlation radius of the isotropic Heisenberg model is fitted by the dependence 1/xi = 2.05T(1.0(6))/exp (1.0(4)/T).The temperature behavior of the static structural magnetic factor in La(2)CuO(4) and Er(2)CuO(4) for T T(N) is in agreement with the MC calculations.

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Держатели документа:
LV Kirenskii Inst Phys, Siberian Branch, Krasnoyarsk 660036, Russia
ИФ СО РАН

Доп.точки доступа:
Аплеснин, Сергей Степанович
}
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7.


    Aplesnin, S. S.
    Quantum spin liquid in an antiferromagnet with four-spin interactions / S. S. Aplesnin // Phys. Solid State. - 1997. - Vol. 39, Is. 8. - P. 1246-1250, DOI 10.1134/1.1130054. - Cited References: 14 . - ISSN 1063-7834
РУБ Physics, Condensed Matter
Рубрики:
MONTE-CARLO
   LA2CUO4

   STATE

Аннотация: A quantum Monte Carlo study of the anisotropic antiferromagnet with four-spin interaction (K) and with spin S= 1/2 on a square lattice is reported. Temperature dependences of the capacity, susceptibility, spin correlation functions, and correlation length, and field dependences of magnetization are calculated. Phase diagrams of the ground-state antiferromagnet and gap (K0) and gapless (K0) quantum spin liquids are determined in the exchange-anisotropy-four-spin-coupling-constant (K), magnetic-field (H)-temperature (T), and temperature- (T)-K planes for an exchange anisotropy of 0.1 J. (C) 1997 American Institute of Physics.

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Держатели документа:
Kirenskii Inst. of Physics, Siberian Br. Russ. Acad. of Sci., 660036 Krasnoyarsk, Russian Federation
ИФ СО РАН

Доп.точки доступа:
Аплеснин, Сергей Степанович
}
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8.


    Ovchinnikov, S. G.
    Density of hole-doped states in strongly correlated electron-systems of copper oxides / S. G. Ovchinnikov // Phys. Rev. B. - 1994. - Vol. 49, Is. 14. - P. 9891-9897, DOI 10.1103/PhysRevB.49.9891. - Cited References: 34 . - ISSN 0163-1829
РУБ Physics, Condensed Matter
Рубрики:
DYNAMIC PROPERTIES
   SUPERCONDUCTIVITY

   GAP

   LA2CUO4

   BI2SR2CACU2O8

   PHOTOEMISSION

   SPECTROSCOPY

   SPECTRA

   MODEL

   BAND

Аннотация: A generalized tight-binding method to calculate quasiparticle band structure and density of states in strongly correlated systems is presented. The band structures of undoped and weakly hole-doped CuO2 layer are calculated. The insulator gap has a charge transfer nature with a minor contribution from a Cu-O Coulomb interaction. Doping results in the appearance of an in-gap state with a simultaneous decrease of the density of states at the band edges in agreement with small cluster results and experimental data.

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Держатели документа:
L. V. Kyrensky Institute of Physics, Siberian Branch of Russian Academy of Sciences, Krasnoyarsk 660036, Russian Federation

Доп.точки доступа:
Овчинников, Сергей Геннадьевич
}
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9.


    Avramov, P. V.
    The strong electron correlation effects in XAFS spectra of HTSC cuprates / P. V. Avramov, S. G. Ovchinnikov // J. Phys. IV. - 1997. - Vol. 7: 9th International Conference on X-Ray Absorption Fine Structure (AUG 26-30, 1996, GRENOBLE, FRANCE), Is. C2. - P. 183-185. - Cited References: 11 . - ISSN 1155-4339
РУБ Physics, Multidisciplinary
Рубрики:
X-RAY-ABSORPTION
   MULTIPLE-SCATTERING ANALYSIS

   EDGE STRUCTURE

   LA2CUO4

   XANES

Аннотация: Theoretical XAFS spectra of highly correlated copper oxides have been presented as a product of a single-electron part obtained by the SCF X alpha- SW method, and a multi-electron part obtained by the multi-band multi-electron p-d model. The main line of CuK-spectrum of La2CuO4 was aligned to the Cud(10) (L) under bar configuration and the single satellite line was aligned to the Cud(9). Comparison of the theoretical data with the experimental ones shows that the ground state of the two-holes in the CuO4 doped cell is triplet. The last conclusion has been confirmed by analysis of CuL2,3-spectra of two-hole impurity states of doped CuO4 cell. Another interesting future of CuL2,3-spectra a peak 2.8 eV higher the threshold was aligned to the transitions into quasi-stationary states due to existence of a high barrier in the Cud-state potential.

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Доп.точки доступа:
Ovchinnikov, S. G.; Овчинников, Сергей Геннадьевич; Аврамов, Павел Вениаминович
}
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10.


    Ovchinnikov, S. G.
    Modification of magnetic and superconducting properties of layered cuprates due to copper substitution for zinc and nickel / S. G. Ovchinnikov // Fiz. Tverd. Tela. - 1995. - Vol. 37, Is. 12. - P. 3645-3654. - Cited References: 28 . - ISSN 0367-3294
РУБ Physics, Condensed Matter
Рубрики:
ELECTRONIC-STRUCTURE
   LA2CUO4

   LA2-XSRXCUO4

   EXCITATIONS

   DENSITY

   PLANE

   NI


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11.


    Avramov, P. V.
    Effects of the intense electron correlations on the shape of x-ray CuK absorption spectra of La2-xSrxCuO4 / P. V. Avramov, S. G. Ovchinnikov // Zhurnal Eksperimentalnoi Teor. Fiz. - 1995. - Vol. 108, Is. 4. - P. 1479-1488. - Cited References: 28 . - ISSN 0044-4510
РУБ Physics, Multidisciplinary
Рубрики:
HIGH-TC SUPERCONDUCTIVITY
   EDGE STRUCTURE

   LA2CUO4

   SATELLITES

   ALPHA

   EXCITATIONS

   COPPER

   OXIDES

   STATE

   SHAKE


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Доп.точки доступа:
Ovchinnikov, S. G.; Овчинников, Сергей Геннадьевич; Аврамов, Павел Вениаминович
}
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12.


    Ovchinnikov, S. G.
    Effects of intense electron correlations on x-ray and x-ray electron copper spectra of high-temperature superconductors / S. G. Ovchinnikov, P. V. Avramov // Fiz. Tverd. Tela. - 1995. - Vol. 37, Is. 9. - P. 2559-2567. - Cited References: 22 . - ISSN 0367-3294
РУБ Physics, Condensed Matter
Рубрики:
HIGH-ENERGY SPECTROSCOPY
   HIGH-TC SUPERCONDUCTORS

   SATELLITES

   LA2CUO4

   OXIDES

   HOLES

   STATE


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Доп.точки доступа:
Avramov, P. V.; Аврамов, Павел Вениаминович; Овчинников, Сергей Геннадьевич
}
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13.


    OVCHINNIKOV, S. G.
    EFFECT OF SUBSTITUTIONAL IMPURITY SPECIES ON THE SUPPRESSION OF MAGNETIC-PROPERTIES OF WEAKLY DOPED COPPER OXIDES / S. G. OVCHINNIKOV // Fiz. Tverd. Tela. - 1994. - Vol. 36, Is. 5. - P. 1307-1310. - Cited References: 16 . - ISSN 0367-3294
РУБ Physics, Condensed Matter
Рубрики:
ELECTRONIC-STRUCTURE
   SUPERCONDUCTIVITY

   LA2CUO4

   EXCITATIONS

   SPECTRA


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14.


    Avramov, P. V.
    Non-diagram transitions in polarized X-ray absorption CuL(3) spectra of HTSC-ceramics / P. V. Avramov, S. G. Ovchinnikov // Fiz. Tverd. Tela. - 1996. - Vol. 38, Is. 11. - P. 3226-3240. - Cited References: 28 . - ISSN 0367-3294
РУБ Physics, Condensed Matter
Рубрики:
HIGH-TC SUPERCONDUCTIVITY
   LA2CUO4

   ALPHA

   SATELLITES

   STATES

   OXIDES

   XANES


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Доп.точки доступа:
Ovchinnikov, S. G.; Овчинников, Сергей Геннадьевич; Аврамов, Павел Вениаминович
}
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