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 (6)
Формат представления найденных документов:
полный информационныйкраткий
Отсортировать найденные документы по:
авторузаглавиюгоду изданиятипу документа
Поисковый запрос: (<.>K=oxide<.>)
Общее количество найденных документов : 194
Показаны документы с 1 по 20
1.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Aleksandrov K. S., Khrustalev B. P., Krivomazov S. N., Петров, Михаил Иванович, Vasilyev A. D., Zwegintsev S. A.
Заглавие : Superconductivity near liquid nitrogen temperature in the Sn-Ba-Sr-Y-Cu-O system
Место публикации : Physica C-Superconductivity and its Applications. - 1989. - Vol. 161, Is. 4. - P.493-496. - ISSN 0921-4534, DOI 10.1016/0921-4534(89)90087-7
Ключевые слова (''Своб.индексиров.''): ceramic materials--tin compounds--bulk superconductivity--high temperature superconductors--oxide superconductors--tin barium strontium yttrium copper oxide--superconducting materials
Аннотация: A high-Tc phase was found in the Sn-Ba-Sr-Y-Cu-O system. DC susceptibility data of Sn2Ba2Sr0.5Y0.5Cu3Ox show a single transition to bulk superconductivity with an onset temperature of 86 K. В© 1989.
Scopus
Найти похожие
2.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Ovchinnikov S. G., Petrakovsky G. A.
Заглавие : Quasi-particle spectrum in copper oxides
Разночтения заглавия :авие SCOPUS: Quasiparticle spectrum in copper oxides
Место публикации : J. Supercond. - 1991. - Vol. 4, Is. 6. - P.437-448. - ISSN 0896-1107, DOI 10.1007/BF00635862
Примечания : Cited References: 0
Ключевые слова (''Своб.индексиров.''): electron correlations--electron energy structure--copper oxide--photoemission data--copper oxide--electron correlations--electron energy structure--photoemission data--ceramic materials--lanthanum compounds--fermi liquid--lanthanum strontium copper oxides--oxide superconductors--quasi particles--high temperature superconductors
Аннотация: The results of electronic structure calculations of the CuO2 layer, performed by the generalized tight-binding method, are presented. The strong electron correlations on both the Cu and O ions are included explicitly. The resulting quasiparticle band structure contains an insulator gap for undoped compounds like La2CuO4. The valence band consists of a large number of narrow Hubbard quasiparticle bands. The dispersion law of quasiparticles at the top of the valence band has a minimum at the GAMMA-point, indicating the existence of the multivalley Fermi surface in the doped La2-xSrxCuO4. The origin of the Fermi liquid behavior in the narrow quasiparticle bands is discussed.
WOS,
Scopus
Найти похожие
3.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Babkin E. V., Koval K. P., Pynko V. G.
Заглавие : Magnetic-properties of ferrimagnetic iron-oxide gamma-Fe2O3
Место публикации : Zhurnal Eksperimentalnoi Teor. Fiz. - 1991. - Vol. 100, Is. 2. - P.582-589. - ISSN 0044-4510
Примечания : Cited References: 10
Аннотация: The results of an investigation of the magnetic properties of iron oxide gamma-Fe2O3 are presented. Epitaxial crystallization on a magnesium oxide backing ensured the stability of the compound in a broad temperature range. The temperature dependences of the magnetization and magnetic anisotropy constants are measured. The magnetization of the sublattices and the single-ion anisotropy constants foh the Fe3+ ion are determined. A magnetic anisotropy induced by the growth of the film is observed, its nature being dependent on the crystallographic orientation of the backing. It is shown that the cause of the appearance of the anisotropy is the ordering of the cation vacancies during the growth of the film.
WOS
Найти похожие
4.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Chechin G. M., Sakhnenko V. P., Misyul S. V., Aleksandrov K. S.
Заглавие : Improper ferroelectric phase due to condensation of two order parameters in crystals of high-temperature superconductors
Место публикации : Ferroelectrics. - 1992. - Vol. 130, Is. 1. - P.155-162. - ISSN 0015-0193
Примечания : Cited References: 21
Предметные рубрики: TRANSITIONS
FERROELASTICS
RB3CD2CL7
Ключевые слова (''Своб.индексиров.''): ceramic materials--crystals--ferroelectricity--phase diagrams--order parameters--oxide superconductors--high temperature superconductors
Аннотация: Using group-theoretical methods it is shown that improper ferroelectric phase may arise in high-temperature superconductors (HTSC) where high-symmetry phases have space groups D4h1 or D4h17. Their appearance is caused by condensation of order parameters (OP's) transforming two irreducible representations (IR's). The most typical phase diagrams are considered, as well as temperature dependence of OP's and the basic structural mechanism of the ferroelectricity arising in the HTSC.
Scopus,
WOS,
Смотреть статью
Найти похожие
5.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Ovchinnikov S. G.
Заглавие : EFFECT OF ANTIFERROMAGNETIC ORDERING ON ZONE STRUCTURE OF LA2CUO4
Место публикации : Zhurnal Eksperimentalnoi Teor. Fiz.: MEZHDUNARODNAYA KNIGA, 1995. - Vol. 107, Is. 3. - P796-811. - ISSN 0044-4510
Примечания : Cited References: 42
Предметные рубрики: HIGH-TC SUPERCONDUCTORS
ELECTRONIC-STRUCTURE
OXIDE SUPERCONDUCTORS
CHARGE-TRANSFER
CUO2 PLANE
MODEL
HOLE
SPECTRUM
STATE
WOS
Найти похожие
6.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Petrov M. I., Balaev D. A., Ospishchev S. V., Shaikhutdinov K. A., Khrustalev B. P., Aleksandrov K. S.
Заглавие : Characteristics of current flow in composites made from a high-temperature superconductor and the low-temperature superconducting metal oxide Ba(PbBi)O-3
Место публикации : Phys. Solid State: American Institute of Physics, 1997. - Vol. 39, Is. 3. - P.362-368. - ISSN 1063-7834, DOI 10.1134/1.1130134
Примечания : Cited References: 21
Предметные рубрики: BAPB1-XBIXO3 SYSTEM
YBA2CU3O7-DELTA
Аннотация: Composites are prepared from a high-temperature superconductor with the 1-2-3 structure and the low-temperature oxide BaPb3/4Bi1/4O3 with various volume concentrations of the high-temperature and low-temperature superconductors. The temperature dependences of the electrical resistivities and critical current densities of the composites are measured. It is shown experimentally that these composites comprise a synthetically created network of Josephson weak links (with a specified degree of coupling). (C) 1997 American Institute of Physics.
WOS
Найти похожие
7.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Zamkova N. G., Zinenko V. I.
Заглавие : Lattice dynamics of ionic crystals in a model of "breathing" and polarizable ions
Место публикации : Phys. Solid State: AMER INST PHYSICS, 1998. - Vol. 40, Is. 2. - P320-324. - ISSN 1063-7834, DOI 10.1134/1.1130302
Примечания : Cited References: 14
Предметные рубрики: OXIDE
Аннотация: An expression is written down for the dynamic matrix of ionic crystals in terms of a microscopic, parameterless model of "breathing" and polarizable ions. Results from a calculation of the complete spectrum of the lattice vibrations of ionic crystals having an NaCl structure are presented as an illustration. (C) 1998 American Institute of Physics.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
8.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Kuz'min E. V., Ovchinnikov S. G., Baklanov I. O., Goryachev E. G.
Заглавие : Microscopic model of the coexistence of superconductivity and ferromagnetism in the hybrid ruthenate-cuprate oxide RuSr2GdCu2O8
Место публикации : J. Exp. Theor. Phys.: AMER INST PHYSICS, 2000. - Vol. 91, Is. 2. - P353-360. - ISSN 1063-7761, DOI 10.1134/1.1311995
Примечания : Cited References: 37
Предметные рубрики: T-J MODEL
HUBBARD-MODEL
LAYERED PEROVSKITE
SR2RUO4
ELECTRONS
COPPER
SPECTRUM
Аннотация: A microscopic t-J-I model with competing antiferromagnetic (J) and ferromagnetic (I) exchange interactions is proposed for strongly correlated electrons in RuSr2GdCu2O8 . It is assumed that J much greater than I for CuO2 layers and J much less than I for RuO2 layers. A superconducting solution of d(x2-y2) symmetry was obtained for the CuO2 layers while competition between ferromagnetism and p-type triplet superconducting pairing is obtained for RuO2 layers. It is shown that the RuO2 layers have a lower carrier concentration in the Hubbard subband formed by coupled ((d(xy)-p)-pi) orbitals compared with a bulk Sr2RuO4 crystal, which leads to stabilization of the ferromagnetic state in the RuO2 layer. (C) 2000 MAIK "Nauka/Interperiodica".
WOS,
Читать в сети ИФ
Найти похожие
9.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Avramov P. V., Ovchinnikov S. G.
Заглавие : Effects of strong electron correlations in X-ray and electron spectra of high-T-c superconductors
Место публикации : Phys. Solid State: AMER INST PHYSICS, 2000. - Vol. 42, Is. 5. - P788-809. - ISSN 1063-7834, DOI 10.1134/1.1131293
Примечания : Cited References: 92
Предметные рубрики: HIGH-TEMPERATURE SUPERCONDUCTORS
COPPER-OXIDE SUPERCONDUCTORS
MULTIPLE-SCATTERING ANALYSIS
HIGH-ENERGY SPECTROSCOPY
ABSORPTION-SPECTRA
PHOTOELECTRON-SPECTRA
EDGE STRUCTURE
PHOTOEMISSION SPECTRA
INCOMPLETE SHELL
SINGLE-CRYSTAL
Аннотация: The current state of theoretical and experimental studies on the electronic structure of high-T-c superconductors is analyzed. The agreement between the theory and experimental spectroscopic data is shown to be rather poor in certain cases. The reason is that the X-ray and electronic spectra reveal strong electron correlations. At the same time, no realistic model has been developed up to now in which both one-electron and multielectron mechanisms of the formation of the spectra could be described in a unified way in compounds containing transition and rare-earth elements. In this paper, particular attention is paid to a sudden-perturbation model, by which it has been possible to describe or interpret some X-ray and electronic spectra, including both one-electron and multielectron effects. (C) 2000 MAIK "Nauka/Interperiodica".
WOS,
Читать в сети ИФ
Найти похожие
10.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Potseluyko A. M., Edelman I. S., Zabluda V. N., Bolsunovskaya O. A., Zamkov A. V., Parshikov S. A., Zaytsev A. I.
Заглавие : Magnetooptic activity of f-d and f-f electron transitions in Pr3+ in the glass matrix LiB3O5
Место публикации : Physica B. - 2000. - Vol. 291, Is. 1-2. - P.89-96. - ISSN 0921-4526, DOI 10.1016/S0921-4526(99)01869-4
Примечания : Cited References: 17
Предметные рубрики: FARADAY-ROTATION
OXIDE GLASSES
Ключевые слова (''Своб.индексиров.''): faraday rotation--magnetooptic activity--praseodymium--electron transitions--faraday effect--light absorption--lithium compounds--praseodymium compounds--faraday rotation--transition wavelength--optical glass
Аннотация: The results of absorption, Faraday rotation and magnetic circular dichroism measurements for glasses with the composition of LiB3O5 + Pr2O3 are presented. The effective wavelength of the transition giving the main contribution to Faraday rotation in these glasses is determined. The contributions of several f-f transitions to Faraday rotation are separated and their magnetooptical activities are evaluated in comparison with the activity of the f-d transition. (C) 2000 Elsevier Science B.V. All rights reserved.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
11.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Edelman I. S., Malakhovskii A. V., Potseluyko A. M., Zarubina T. V., Zamkov A. V.
Заглавие : Intensities f-f transitions in Pr3+ and Dy3+ in glasses in the near-IR spectral range
Место публикации : Phys. Solid State: AMER INST PHYSICS, 2001. - Vol. 43, Is. 6. - P1037-1042. - ISSN 1063-7834, DOI 10.1134/1.1378142
Примечания : Cited References: 21
Предметные рубрики: OXIDE GLASSES
Аннотация: The absorption spectra of Pr3+ and Dy3+ ions in three glass matrices (SiO2-P2O5-GeO2, Al2O3-B2O3-SiO2, and LiB3O5) are thoroughly studied in the near-IR spectral range (4600-14 300 cm(-1)). The temperature dependences of the intensity, the width, and the location of the absorption bands observed are investigated for the first time. It is shown that the f-f transitions in the studied glasses ate allowed by static odd distortions in the environment of the rare-earth ions and these distortions decrease with an increase in temperature. A comparative analysis of the absorption band parameters and their temperature behavior in different materials makes it possible to determine the differences in magnitudes, symmetries, and dispersions of the distortions in the nearest environment of rare-earth ions in different glasses. (C) 2001 MAIK "Nauka/Interperiodica".
WOS,
Читать в сети ИФ
Найти похожие
12.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Nasluzov V. A., Rivanenkov V. V., Gordienko A. B., Neyman K. M., Birkenheuer U., Rosch N.
Заглавие : Cluster embedding in an elastic polarizable environment: Density functional study of Pd atoms adsorbed at oxygen vacancies of MgO(001)
Место публикации : J. Chem. Phys.: AMER INST PHYSICS, 2001. - Vol. 115, Is. 17. - P8157-8171. - ISSN 0021-9606, DOI 10.1063/1.1407001
Примечания : Cited References: 88
Предметные рубрики: TRANSITION-METAL ATOMS
AB-INITIO
OXIDE SURFACES
ELECTRONIC-PROPERTIES
ENERGY CALCULATIONS
MOLECULAR-DYNAMICS
MOTT-LITTLETON
MADELUNG FIELD
IONIC-CRYSTAL
MGO
Ключевые слова (''Своб.индексиров.''): atoms--binding energy--computer simulation--electron energy levels--electronic structure--magnesia--oxygen--palladium--polarization--probability density function--quantum theory--relaxation processes--charged defects--cluster embedding--elastic polarizable environment--electron affinity--oxygen vacancies--adsorption
Аннотация: Adsorption complexes of palladium atoms on F-s, F-s(+), F-s(2+), and O2- centers of MgO(001) surface have been investigated with a gradient-corrected (Becke-Perdew) density functional method applied to embedded cluster models. This study presents the first application of a self-consistent hybrid quantum mechanical/molecular mechanical embedding approach where the defect-induced distortions are treated variationally and the environment is allowed to react on perturbations of a reference configuration describing the regular surface. The cluster models are embedded in an elastic polarizable environment which is described at the atomistic level using a shell model treatment of ionic polarizabilities. The frontier region that separates the quantum mechanical cluster and the classical environment is represented by pseudopotential centers without basis functions. Accounting in this way for the relaxation of the electronic structure of the adsorption complex results in energy corrections of 1.9 and 5.3 eV for electron affinities of the charged defects F-s(+) and F-s(2+), respectively, as compared to models with a bulk-terminated geometry. The relaxation increases the stability of the adsorption complex Pd/F-s by 0.4 eV and decreases the stability of the complex Pd/F-s(2+) by 1.0 eV, but it only weakly affects the binding energy of Pd/F-s(+). The calculations provide no indication that the metal species is oxidized, not even for the most electron deficient complex Pd/F-s(2+). The binding energy of the complex Pd/O2- is calculated at -1.4 eV, that of the complex Pd/F-s(2+) at -1.3 eV. The complexes Pd/F-s and Pd/F-s(+) exhibit notably higher binding energies, -2.5 and -4.0 eV, respectively; in these complexes, a covalent polar adsorption bond is formed, accompanied by donation of electronic density to the Pd 5s orbital. (C) 2001 American Institute of Physics.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
13.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Ovchinnikov S. G.
Заглавие : Exotic superconductivity and magnetism in ruthenates
Место публикации : Phys. Usp.: TURPION LTD, 2003. - Vol. 46, Is. 1. - P21-44. - ISSN 1063-7869, DOI 10.1070/PU2003v046n01ABEH001235
Примечания : Cited References: 167
Предметные рубрики: ITINERANT FERROMAGNET SRRUO3
SPIN-TRIPLET SUPERCONDUCTIVITY
STRONGLY CORRELATED ELECTRONS
T-J-MODEL
J-I-MODEL
TRANSPORT-PROPERTIES
MOTT-INSULATOR
FERMI-SURFACE
LAYERED PEROVSKITE
RUTHENIUM OXIDES
Ключевые слова (''Своб.индексиров.''): electronic structure--magnetic properties--magnetism--oxide superconductors--strontium alloys--superconductivity--electron correlations--ruthenates--rutheno-cuprates--spin-triplet pairing--ruthenium compounds
Аннотация: Basic experimental and theoretical results on ruthenates and rutheno-cuprates are reviewed. The electronic structure of various ruthenates and exotic superconductivity in Sr2RuO4 with spin-triplet pairing are described. The complex phase diagram of Ca2-xSrxRuO4, involving competing magnetic phases and metal-insulator transitions, is described, as are the exotic magnetic properties of Sr3Ru2O7 and of the double perovskite Sr2YRuO6, and the coexistence of superconductivity and magnetism in the rutheno-cuprate RuSr2GdCu2O8. Possible applications of Sr2RuO4 and SrRuO3 are considered. The effect of strong electron correlations is discussed, and the properties of ruthenates and cuprates are compared.
WOS,
Scopus
Найти похожие
14.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Kliava J., Edelman I. S., Potseluyko A. M., Petrakovskaja E. A., Berger R., Bruckental I., Yeshurun Y., Malakhovskii A. V., Zarubina Y. V.
Заглавие : Magnetic and optical properties and electron paramagnetic resonance of gadolinium-containing oxide glasses
Место публикации : J. Phys.: Condens. Matter: IOP PUBLISHING LTD, 2003. - Vol. 15, Is. 40. - P6671-6681. - ISSN 0953-8984, DOI 10.1088/0953-8984/15/40/005
Примечания : Cited References: 30
Предметные рубрики: ABSORPTION-SPECTRA
FARADAY-ROTATION
SPIN-RESONANCE
IONS
GD3+
SPECTROSCOPY
BEHAVIOR
GD-3
Ключевые слова (''Своб.индексиров.''): doping (additives)--electronic structure--glass--lanthanum compounds--light absorption--magnetic susceptibility--oxides--paramagnetic resonance--positive ions--rate constants--substitution reactions--absorption band--gadolinium containing oxide glasses--positive weiss constants--gadolinium compounds
Аннотация: Magnetic susceptibility, electron paramagnetic resonance (EPR) and optical absorption have been studied in a glass system 20La(2)O(3)-22Al(2)O(3)-23B(2)O(3)-35(SiO2 + GeO2) with a part of La2O3 substituted by Gd2O3 in different concentrations. Positive Weiss constants have been found in more heavily doped glasses and ascribed to clustering of Gd3+ ions. Computer simulations of the EPR spectra show that the short-range ordering in the environment of the Gd3+ ions is well preserved. The relative distribution widths of the ligand coordinates are less than 2%. In the more heavily doped glasses the EPR spectra are superpositions of signals arising from isolated ions and ferromagnetic clusters. The increase of Gd3+ concentration is shown to change substantially the strong optical absorption edge while only small changes of f-f absorption band characteristics are observed. This difference is associated with the different effect of the Gd ion clustering on the mechanisms of the strong absorption in the ultraviolet region and the f-f absorption.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
15.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Balaev D. A., Ospishchev S. V., Petrov M. I., Aleksandrov K. S.
Заглавие : The effect of paramagnetic impurities in normal metal on the critical current in a network of S-N-S Josephson junctions in bulk Y3/4Lu1/4Ba2Cu3O7+BaPb(1-x)Fe(x)O(3)composites
Разночтения заглавия :авие SCOPUS: The effect of paramagnetic impurities in normal metal on the critical current in a network of S-N-S Josephson junctions in bulk Y3/4Lu1/4Ba2Cu3O7 + BaPb1-xFexO3 composites
Место публикации : Supercond. Sci. Technol. - 2003. - Vol. 16, Is. 1. - P.60-64. - ISSN 0953-2048, DOI 10.1088/0953-2048/16/1/311
Примечания : Cited References: 41
Предметные рубрики: CURRENT-VOLTAGE CHARACTERISTICS
WEAK LINKS
RESISTIVE PROPERTIES
MAGNETIC-IMPURITIES
EXCHANGE FIELD
SNS JUNCTIONS
F-S
COMPOSITES
SUPERCONDUCTOR
SCATTERING
Ключевые слова (''Своб.индексиров.''): critical currents--interfaces (materials)--josephson junction devices--paramagnetism--transport properties--non-superconducting ingredient--paramagnetic impurities--superconductor normal metal superconductor--oxide superconductors
Аннотация: Bulk Y3/4Lu1/4Ba2Cu3O7 + BaPb1-xFexO3 composites representing a model of a network of superconductor-normal metal-superconductor (SNS) Josephson junctions with paramagnetic impurities (Fe) in the N layers have been prepared. The transport properties of the composites have been studied. An exponential decay of the critical current with increasing Fe content in the non-superconducting ingredient of the composite has been observed. Such a behaviour is accounted for in terms of the de Gennes proximity effect theory.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
16.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Balaev D. A., Shaihutdinov K. A., Popkov S. I., Gokhfeld D. M., Petrov M. I.
Заглавие : Magnetoresistive effect in bulk composites 1-2-3 YBCO+CuO and 1-2-3 YBCO+BaPb(1-x)SnxO(3) and their application as magnetic field sensors at 77 K
Разночтения заглавия :авие SCOPUS: Magnetoresistive effect in bulk composites 1-2-3 YBCO + CuO and 1-2-3 YBCO + BaPb1-xSnxO3 and their application as magnetic field sensors at 77 K
Место публикации : Supercond. Sci. Technol.: IOP PUBLISHING LTD, 2004. - Vol. 17, Is. 1. - P175-181. - ISSN 0953-2048, DOI 10.1088/0953-2048/17/1/031
Примечания : Cited References: 27
Предметные рубрики: PHASE-SLIP
SUPERCONDUCTOR
TEMPERATURE
YBA2CU3O7-DELTA
TRANSITION
Ключевые слова (''Своб.индексиров.''): ceramic materials--composite materials--critical current density (superconductivity)--high temperature operations--high temperature superconductors--lead compounds--magnetoresistance--sensors--yttrium barium copper oxides--high temperature superconductor ceramics--magnetic field sensors--magnetoresistive effect--transport current density--oxide superconductors
Аннотация: We have studied the magnetoresistive effect in bulk 1-2-3 YBCO + CuO and 1-2-3 YBCO + BaPb1-xSnxO3 composites prepared using the fast backing technique. We have found that the composites exhibit large magnetoresistance in low magnetic fields ( 100 Oe) for a broad temperature range. We have studied the experimental dependences of resistivity versus magnetic field at various transport current densities. The high-T-C superconductor (HTSC) based composites exhibit a much higher sensitivity to weak magnetic fields at liquid nitrogen temperature, compared to that for pure HTSC ceramics. This effect is attractive for practical applications and the composite materials can be used as active elements in magnetic field sensor devices.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
17.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Korshunov M. M., Gavrichkov V. A., Ovchinnikov S. G., Manske D., Eremin I.
Заглавие : Effective parameters of the band dispersion in n-type high-T-c superconductors
Разночтения заглавия :авие SCOPUS: Effective parameters of the band dispersion in n-type high-Tc superconductors
Место публикации : Physica C: ELSEVIER SCIENCE BV, 2004. - Vol. 402, Is. 4. - P365-370. - ISSN 0921-4534, DOI 10.1016/j.physc.2003.10.017
Примечания : Cited References: 32
Предметные рубрики: DOPED CUPRATE SUPERCONDUCTORS
TIGHT-BINDING METHOD
QUASI-PARTICLES
COPPER OXIDES
LA2-XSRXCUO4
SYMMETRY
MODEL
EVOLUTION
ORDER
Ключевые слова (''Своб.индексиров.''): high-t-c superconductivity--electronic correlations--electron-doped cuprates--electron-doped cuprates--electronic correlations--high-tc superconductivity--approximation theory--atomic physics--band structure--binding energy--charge transfer--correlation methods--doping (additives)--electronic structure--hamiltonians--mathematical models--mathematical operators--oxide superconductors--perturbation techniques--photoelectron spectroscopy--atomic orbitals--conduction band--electron doped cuprates--electron spins--valence band--high temperature superconductors
Аннотация: The electronic structure of electron-doped cuprates is discussed in the regions of small and optimal doping. For optimal doping we obtain the parameters from a simple tight-binding analysis by fitting ARPES data, and for small doping we study the band structure by the generalized tight-binding method that takes strong electronic correlations into account explicitly. This method has also reproduced well the ARPES data for small doping. The effective low-energy Hamiltonian is the t-t'-J model with hopping parameters t and t'. We compare both methods and find very good agreement for the value of t while t' is different because it is caused by the different contribution of the short-range spin correlations. (C) 2003 Elsevier B.V. All rights reserved.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
18.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Kliava J., Malakhovskii A. V., Edelman I. S., Potseluyko A. M., Petrakovskaja E. A., Melnikova S.V., Zarubina T. V., Petrovskii G., Bruckental Y., Yeshurun Y.
Заглавие : Unusual magnetic transitions and nature of magnetic resonance spectra in oxide glasses containing gadolinium
Место публикации : Phys. Rev. B: AMER PHYSICAL SOC, 2005. - Vol. 71, Is. 10. - Ст.104406. - ISSN 1098-0121, DOI 10.1103/PhysRevB.71.104406
Примечания : Cited References: 40
Предметные рубрики: ELECTRON-PARAMAGNETIC-RESONANCE
BORATE GLASSES
IONS
BEHAVIOR
GD3+
SPECTROSCOPY
SYSTEMS
GD-3+
FIELD
SHAPE
Ключевые слова (''Своб.индексиров.''): gadolinium--glass--lanthanide--oxide--anisotropy--article--chemical structure--concentration response--electron spin resonance--energy--magnetism--molecular physics--nanoparticle--phase transition--refraction index--temperature sensitivity
Аннотация: Magnetic susceptibility, electron paramagnetic resonance (EPR), and optical properties have been studied in a glass system {20La(2)O(3)-22Al(2)O(3)-23B(2)O(3)-35(SiO2+GeO2)} with a part of La2O3 substituted by Gd2O3 in different concentrations. Positive Weiss constants have been found in the more heavily doped glasses and ascribed to clustering of Gd3+ ions. Two magnetic phase transitions at 55 and 12 K were detected and ascribed, respectively, to ferromagnetic and antiferromagnetic clusters containing Gd ions. The overall shape of the EPR spectra shows the presence of clustering at the higher Gd contents. At low temperatures the cluster-related resonance signal is altered in shape, indicating an onset of magnetic anisotropy field. This signal is convincingly fitted to superparamagnetic resonance arising from ferromagnetic nanoparticles. The clustering, depending on the Gd concentration, correlates with a significant shift to lower energies of the strong optical absorption band edge, ascribed to a charge transfer transition between Gd ions. A nonmonotonous change of refractive index with the increase of the Gd content indicates changes in the glass matrix and in Gd cluster structure.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
19.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Kazak N. V., Ovchinnikov S. G., Abd-Elmeguid M. M., Ivanova N. B.
Заглавие : Electronic properties of Fe1-xVxBO3 at ambient conditions and at high pressure
Разночтения заглавия :авие SCOPUS: Electronic properties of Fe1-xVx-BO3 at ambient conditions and at high pressure
Место публикации : J. Phys.: Condens. Matter: IOP PUBLISHING LTD, 2005. - Vol. 17: 2nd International Symposium on Physics of Solids Under High Pressure Using Nuclear Probes (JUL 20-24, 2004, Cologne, GERMANY), Is. 11. - P.S795-S800. - ISSN 0953-8984, DOI 10.1088/0953-8984/17/11/008
Примечания : Cited References: 16
Предметные рубрики: FEBO3 SINGLE-CRYSTALS
SOLID-SOLUTIONS
BAND-STRUCTURE
TRANSITION
MOSSBAUER
MAGNETIZATION
MODEL
VBO3
Ключевые слова (''Своб.индексиров.''): electronic properties--ferrimagnetic materials--high pressure effects--high temperature superconductors--metal insulator transition--single crystals--superconductivity--thermal effects--carrier localization--correlation effects--critical pressure--semiconducting behavior--oxide superconductors
Аннотация: We present the results of an in-plane resistivity study of the solid solutions Fe1-xVxBO3. The measurements were made on single crystals with concentration x = 0.02, 0.13, 0.18, 0.3, 0.95, 1.0 in the temperature range 220-600 K. Semiconducting behaviour for samples with x = 0.13 was found. Mott variable-range-hopping transport rho(T) = rho(0)exp(T*/T)(alpha) has been observed with alpha = 1/4 at T 290 K, suggesting carrier localization. Above this temperature the activation-type conductivity, with activation energies, E-a, about 1 eV for all samples, is observed. The possible electronic states and band structure of Fe1-xVx BO3 crystals are discussed in the different pressure ranges: P P-c(Fe), p(c)(Fe) p p(c)(V) P P-c(V) where p(c)(Fe) P-c(V) are the critical pressure values for FeBO3 and VBO3, respectively.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
20.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Korshunov M. M., Ovchinnikov S. G., Sherman A. V.
Заглавие : Effective Hamiltonian and the properties of normal and superconductive phases of n-type cuprates
Место публикации : Physica B: ELSEVIER SCIENCE BV, 2005. - Vol. 359: International Conference on Strongly Correlated Electron Systems (SCES 04) (JUL 26-30, 2004, Karlsruhe, GERMANY). - P521-523. - ISSN 0921-4526, DOI 10.1016/j.physb.2005.01.134
Примечания : Cited References: 13
Предметные рубрики: MODEL
SYMMETRY
Ключевые слова (''Своб.индексиров.''): strong electron correlations--superconductivity--multiband p-d model--n-type cuprates--multiband p-d model--n-type cuprates--strong electron correlations--superconductivity--antiferromagnetism--correlation theory--fermi surface--hamiltonians--mathematical models--microscopic examination--oxide superconductors--phase diagrams--semiconductor doping--generalized tight-binding (gtb)--multiband p-d models--n-type cuprates--single electron correlations--superconductivity
Аннотация: In the framework of the effective low-energy model for high-T-c, cuprates with account for three-center interaction terms and spin fluctuations the properties of normal and superconducting phases of n-type cuprates are investigated. Microscopic model parameters were obtained from ARPES data in undoped compounds. Obtained evolution of the chemical potential with doping, Fermi surface at optimal doping, and T-c(x) phase diagram are in remarkably good agreement with the experiment. (c) 2005 Elsevier B.V. All rights reserved.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
 

Другие библиотеки

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