Библиотека института физики им. Л.В. Киренского СО РАН

Главная

Базы данных

Труды сотрудников ИФ СО РАН - результаты поиска

Вид поиска

Каталог книг и брошюр библиотеки ИФ СО РАН

Каталог журналов библиотеки ИФ СО РАН

Труды сотрудников ИФ СО РАН

Область поиска

в найденном

Формат представления найденных документов:
полный	информационный	краткий

Отсортировать найденные документы по:
автору	заглавию	году издания	типу документа

Поисковый запрос: (<.>K=Doping<.>)

Общее количество найденных документов : 96
Показаны документы с 1 по 20

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : OVCHINNIKOV S. G.
Заглавие : CHANGE OF THE DENSITY OF STATES WITH HOLE DOPING IN CUO2 LAYERS
Место публикации : Zhurnal Eksperimentalnoi Teor. Fiz.: MEZHDUNARODNAYA KNIGA, 1993. - Vol. 103, Is. 4. - P1404-1410. - ISSN 0044-4510
Примечания : Cited References: 7
Аннотация: By means of the exact diagonalization of the many-electron hamiltonian the single-particle density of states is calculated for CuO4 cluster. For undoped case there is a dielectric gap in which new states arise with hole doping. The concentration dependence of the Fermi level is found and the critical concentration of the insulator-metal Anderson transition is evaluated.
WOS
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Patrin G. S., Volkov N. V., Vasiliev V. N.
Заглавие : The ''easy plane easy axis'' transition in alpha-Fe2O3:Ga crystals induced by doping with terbium ions
Место публикации : Phys. Lett. A. - 1997. - Vol. 230, Is. 1-2. - P.96-98. - ISSN 0375-9601, DOI 10.1016/S0375-9601(97)00219-3
Примечания : Cited References: 10
Аннотация: In easy plane weak ferromagnetic alpha-Fe2O3:Ga crystals it was found that doping with a hundredth part of To ions leads to the restoration of the transition into the ''easy axis'' magnetic state. It was established that in the alpha-Fe2O3:Ga, Tb crystal the angular magnetic phase is realized. (C) 1997 Published by Elsevier Science B.V.
WOS
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Gavrichkov V. A., Ovchinnikov S. G., Borisov A. A., Goryachev E. G.
Заглавие : Evolution of the band structure of quasiparticles with doping in copper oxides on the basis of a generalized tight-binding method
Место публикации : J. Exp. Theor. Phys.: AMER INST PHYSICS, 2000. - Vol. 91, Is. 2. - P369-383. - ISSN 1063-7761, DOI 10.1134/1.1311997
Примечания : Cited References: 45
Предметные рубрики: T-J MODEL
CUPRATE SUPERCONDUCTORS
ELECTRONIC-STRUCTURE
EXCITATIONS
DEPENDENCE
TEMPERATURE
DERIVATION
SR2CUO2CL2
SPECTRUM
DENSITY
Аннотация: Two methods for stabilizing the two-hole B-3(1g) state as the ground state instead of the Zhang-Rice singlet are determined on the basis of an orthogonal cellular basis for a realistic multiband pd model of a CuO2 layer and the dispersion relations for the valence band top in undoped and doped cases are calculated. In the undoped case, aside from the valence band, qualitatively corresponding to the experimental ARPES data for Sr2CuO2Cl2 and the results obtained on the basis of the t-t'-J model, the calculations give a zero-dispersion virtual level at the valence band top itself. Because of the zero amplitude of transitions forming the virtual level the response corresponding to it is absent in the spectral density function. In consequence, the experimental ARPES data do not reproduce its presence in this antiferromagnetic undoped dielectric. A calculation of the doped case showed that the virtual level transforms into an impurity-type band and acquires dispersion on account of the nonzero occupation number of the two-hole states and therefore should be detected in ARPES experiments as a high-energy peak in the spectral density. The computed dispersion dependence for the valence band top is identical to the dispersion obtained by the Monte Carlo method, and the ARPES data for optimally doped Bi2Sr2CaCu2O8 + delta samples. The data obtained also make it possible to explain the presence of an energy pseudogap at the symmetric X point of the Brillouin band of HTSC compounds. (C) 2000 MAIK "Nauka/Interperiodica".
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

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

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Borisov A. A., Gavrichkov V. A., Ovchinnikov S. G.
Заглавие : Doping dependence of the band structure and chemical potential in cuprates by the generalized tight-binding method
Коллективы : International Conference on Modern Problems in Superconductivity
Место публикации : Mod. Phys. Lett. B/ International Conference on Modern Problems in Superconductivity (3 ; 2002 ; Sept. ; 9-14 ; Yalta, Ukrain). - 2003. - Vol. 17, Is. 10-12. - P.479-486. - ISSN 0217-9849, DOI 10.1142/S0217984903005500
Примечания : Cited References: 12
Предметные рубрики: CORRELATED ELECTRONS
SUPERCONDUCTIVITY
OXIDES
Аннотация: Quasiparticle band structure in hole doped CuO2 layer is calculated with account for strong electron correlations in the framework of multiband p-d model. For undoped layer we obtain the charge-transfer antiferromagnetic insulator. With doping unusual impurity-like quasiparticle appears at the top of the valence band with spectral weight proportional to doping concentration. In the overdoped regime the band structure in the paramagnetic phase results in the doping dependent Fermi surface in agreement to ARPES data.
WOS
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Borisov A.A., Gavrichkov V. A., Ovchinnikov S. G.
Заглавие : Temperature and concentration dependences of the electronic structure of copper oxides in the generalized tight binding method
Место публикации : J. Exp. Theor. Phys.: AMER INST PHYSICS, 2003. - Vol. 97, Is. 4. - P773-780. - ISSN 1063-7761, DOI 10.1134/1.1625067
Примечания : Cited References: 25
Предметные рубрики: SUPERCONDUCTING-GAP ANISOTROPY
BAND-STRUCTURE
FERMI-SURFACE
NORMAL-STATE
BI2SR2CACU2O8+DELTA
EVOLUTION
Ключевые слова (''Своб.индексиров.''): doping (additives)--electron transitions--electronic structure--fermi level--fermi surface--electron correlations--pseudogap--tight binding method--valence band--copper oxides
Аннотация: The electronic structure of p-type doped HTSC cuprates is calculated by explicitly taking into account strong electron correlations. The smooth evolution of the electronic structure from undoped antiferromagnetic to optimally and heavily doped paramagnetic compositions is traced. For a low doping level, in-gap impurity-type states are obtained, at which the Fermi level is pinned in the low-doping region. These states are separated by a pseudogap from the valence band. The Fermi surfaces calculated for the paramagnetic phase for various concentrations of holes are in good agreement with the results of ARPES experiments and indicate a gradual change in the Fermi surface from the hole type to the electron type. (C) 2003 MAIK "Nauka/Interperiodica".
WOS,
Scopus,
Смотреть статью,
Читать в сети ИФ
Найти похожие

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

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Ovchinnikov S. G., Borisov A. A., Gavrichkov V. A., Korshunov M. M.
Заглавие : Prediction of the in-gap states above the top of the valence band in undoped insulating cuprates due to the spin-polaron effect
Место публикации : J. Phys.: Condens. Matter: IOP PUBLISHING LTD, 2004. - Vol. 16, Is. 8. - PL93-L100. - ISSN 0953-8984, DOI 10.1088/0953-8984/16/8/L04
Примечания : Cited References: 25
Предметные рубрики: ELECTRONIC-STRUCTURE
LA2-XSRXCUO4
MODEL
ANTIFERROMAGNETISM
SPECTRA
OXIDES
Ключевые слова (''Своб.индексиров.''): quasiparticle band structure--spin-polaron effect--antiferromagnetic materials--approximation theory--doping (additives)--electronic structure--hamiltonians--insulation--magnetic fields--strontium compounds--thermal effects--lanthanum compounds
Аннотация: In the framework of the generalized tight binding method we have calculated the quasiparticle band structure and the spectral functions of the undoped cuprates such as La2CuO4, Sr2CUO2Cl2 etc. Due to spin fluctuations the in-gap state appears above the top of the valence band in the undoped antiferromagnetic insulator similar to in-gap states induced by hole doping. In the ARPES experiments the in-gap states can be detected as weak low energy satellites.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Gavrichkov V. A., Ovchinnikov S. G.
Заглавие : The band structure of n-type cuprate superconductors with the T '(T) structure taking into account strong electron correlation
Разночтения заглавия :авие SCOPUS: The band structure of n-type cuprate superconductors with the T′(T) structure taking into account strong electron correlation
Место публикации : J. Exp. Theor. Phys.: AMER INST PHYSICS, 2004. - Vol. 98, Is. 3. - P556-564. - ISSN 1063-7761, DOI 10.1134/1.1705708
Примечания : Cited References: 18. - This work was financially supported by the Russian Foundation for Basic Research (project no. 03-02-16124), RFFI-KKFN “Eniseœ” (project no. 02-02-97705), INTAS (project no. 01-0654), integration program of URO and Siberian Division, Russian Academy of Sciences
Предметные рубрики: QUASI-PARTICLES
COPPER OXIDES
TEMPERATURE
LA2-XSRXCUO4
ND2-XCEXCUO4
EVOLUTION
MOMENTS
Ключевые слова (''Своб.индексиров.''): dielectric properties--electric conductance--electron transitions--electronic structure--fermi level--phase diagrams--semiconductor doping--conduction bands--electron correlation--spectral density--superconducting materials
Аннотация: The spectral density, dispersion relations, and the position of the Fermi level for n-doped compositions based on NCO and LCO were calculated within the framework of the generalized tight binding method. As distinguished from LCO, the dielectric gap in NCO is nonlinear in character. We observe a virtual level both at the bottom of the conduction band and at the top of the valence band in both compounds. However, its position corresponds to the extreme bottom of the conduction band in LCO and is 0.1 - 0.2 eV above the bottom in NCO. This explains why we observe Fermi level pinning in n-LCO as the concentration of the doping component grows and reproduce its absence in NCCO at low doping values. We also found both compositions to be unstable in a narrow concentration range with respect to a nonuniform charge density distribution. The relation between the phase diagram for NCCO and the calculated electronic structure is discussed. (C) 2004 MAIK "Nauka/Interperiodica".
WOS,
Scopus,
РИНЦ,
Смотреть статью,
Читать в сети ИФ
Найти похожие

10.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Korshunov M. M., Gavrichkov V. A., Ovchinnikov S. G., Pchelkina Z. V., Nekrasov I. A., Korotin M. A., Anisimov V. I.
Заглавие : Parameters of the effective singlet-triplet model for band structure of high-T-c cuprates by alternative approaches
Разночтения заглавия :авие SCOPUS: Parameters of the effective singlet-triplet model for band structure of high-Tc cuprates by alternative approaches
Место публикации : J. Exp. Theor. Phys.: AMER INST PHYSICS, 2004. - Vol. 99, Is. 3. - P559-565. - ISSN 1063-7761, DOI 10.1134/1.1809685
Примечания : Cited References: 48
Предметные рубрики: DENSITY-FUNCTIONAL CALCULATION
TIGHT-BINDING METHOD
COPPER OXIDES
ENERGY-BANDS
SUPERCONDUCTORS
HOLE
LA2-XSRXCUO4
PLANE
SR2CUO2CL2
INSULATORS
Ключевые слова (''Своб.индексиров.''): band structure--carbon dioxide lasers--copper oxides--doping (additives)--parameter estimation--electron systems--generalized tight binding (gtb)--parameters extraction--singlet triplet model--technetium compounds
Аннотация: We consider the problem of determining the parameters for high-T-c superconducting copper oxides. Alternative approaches, the ab initio LDA and LDA + U calculations and the generalized tight-binding (GTB) method for strongly correlated electron systems, are used to calculate hopping and exchange parameters of the effective singlet-triplet model for the CuO2 layer. The resulting parameters are in remarkably good agreement with each other and with parameters extracted from experiment. This set of parameters is proposed for proper quantitative description of the physics of hole-doped high-T-c cuprates in the framework of effective models. (C) 2004 MAIK "Nauka / Interperiodica".
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

11.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Ovchinnikov S. G., Gavrichkov V. A., Korshunov M. M.
Заглавие : Electronic structure and its evolution with doping in cuprates with account for strong electron correlations
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). - P1168-1170. - ISSN 0921-4526, DOI 10.1016/j.physb.2005.01.311
Примечания : Cited References: 4
Ключевые слова (''Своб.индексиров.''): strong electron correlations--multiband p-d model--spin-polaron effect
Аннотация: The electronic structure of the undoped and p- and n-type doped cuprates is studied in the framework of the multiband p-d model using the generalized tight binding method. With hole doping, an unusual in-gap state appears just at the top of the valence band with the spectral weight proportional to the doping concentration. The chemical potential dependence on the hole and electron concentration is asymmetrical and in good agreement with the experimental data. The in-gap bands have spin-polaron origin and the spectral function of this band has a form of small low-energy satellite that can be detected in ARPES measurements. (c) 2005 Elsevier B.V. All rights reserved.
WOS,
Читать в сети ИФ
Найти похожие

12.

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

13.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Semenov A. P., Semenova I. A., Bulina N. V., Lopatin V. A., Karmanov N. S., Churilov G. N.
Заглавие : Thin fullerene-containing films synthesized by ion beam sputtering of fullerene mixtures with doping additives in vacuum
Место публикации : Tech. Phys. Lett.: AMER INST PHYSICS, 2005. - Vol. 31, Is. 12. - P1022-1025. - ISSN 1063-7850, DOI 10.1134/1.2150887
Примечания : Cited References: 11
Предметные рубрики: DISCHARGE
Аннотация: A new approach to the synthesis of films containing fullerenes and doping elements is described. It is suggested that a cluster mechanism of the target sputtering by accelerated ions makes possible the deposition of fullerenes on a substrate with a certain probability for dopant atoms being introduced into the cavities of fullerene molecules and a higher probability of their occurrence between fullerene molecules. The proposed method has been experimentally implemented by using an Ar+ ion beam to sputter C-60 /C-70 fullerene mixtures (synthesized in a plasmachemical reactor at a pressure of 10(5) Pa) pressed into disk targets with a doping element (Fe, Na, B, Gd, or Se). The ion beam sputtering of dopant-containing fullerene mixtures in a vacuum of similar to 10(-2) Pa allowed micron-thick films containing C-60 and C-70 fullerenes and the corresponding dopant element (Fe, Na, B, Gd, or Se) to be grown on quartz substrates. (C) 2005 Pleiades Publishing, Inc.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

14.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Gavrichkov V. A., Korshunov M. M., Ovchinnikov S. G.
Заглавие : Doping dependent electronic structure of cuprates and the effective low energy Hamiltonian for the magnetic pairing
Коллективы : International Conference on New Theories, Discoveries and Applications of Superconductors and Related Materials
Место публикации : Int. J. Mod. Phys. B/ International Conference on New Theories, Discoveries and Applications of Superconductors and Related Materials (5 ; 2004 ; June ; 11-16 ; Chongqing, China). - 2005. - Vol. 19, Is. 1-3. - P.247-249. - ISSN 0217-9792, DOI 10.1142/S0217979205028335
Примечания : Cited References: 14
Предметные рубрики: COPPER OXIDES
SYMMETRY
MODEL
Ключевые слова (''Своб.индексиров.''): electronic structure--strong electron correlations--magnetic mechanism of pairing--electronic structure--magnetic mechanism of pairing--strong electron correlations--copper derivative--calculation--chemical reaction--chemical structure--conference paper--correlation analysis--electron--electronics--energy--hybridization--intermethod comparison--magnetism--mathematical analysis--mathematical model
Аннотация: The properties of the normal and superconducting phases of p- and n-type cuprates are investigated in the appropriate low-energy models in the approximation beyond Hubbard I considering spin fluctuations. Calculated chemical potential dependence on doping, Fermi surface and T,(x) phase diagram for n-type cuprates are in remarkably good agreement with the experimental ones. Comparison of the singlet-triplet t-J model with simple t-J model shows that the spin-exciton mechanism originated from singlet-triplet hybridization leads to small contribution to the T-c(x) - optimal doping value becomes slightly lower and the maximum value of T-c become slightly higher.
WOS,
Scopus
Найти похожие

15.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Gavrichkov V. A., Ovchinnikov S. G., Yakimov L. E.
Заглавие : The role of orbital ordering in the formation of electron structure in undoped LaMnO3 manganites in the regime of strong electron correlations
Место публикации : J. Exp. Theor. Phys.: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2006. - Vol. 102, Is. 6. - P972-985. - ISSN 1063-7761, DOI 10.1134/S1063776106060112
Примечания : Cited References: 25
Предметные рубрики: COLOSSAL MAGNETORESISTIVE OXIDES
DOUBLE EXCHANGE
BAND
MODEL
Ключевые слова (''Своб.индексиров.''): computational methods--correlation methods--doping (additives)--electrons--ferromagnetic materials--lanthanum compounds--paramagnetic materials--intraatomic electron correlations--mott hubbard correlation gap--orbital ordering--paramagnetic phases--electronic structure
Аннотация: The electron structure of undoped LaMnO3 and slightly doped La1-xSrxMnO3 manganites has been calculated within the framework of a generalized tight binding method with explicit allowance for strong intra-atomic electron correlations. According to the results of these calculations, the ground state in orbitally disordered undoped LaMnO3 ferromagnets would be metallic despite the Mott-Hubbard correlation gap in the spectrum of quasiparticles. Owing to the orbital ordering, the insulating state is stabilized in both antiferromagnetic and paramagnetic phases. In-gap states of a polaron nature with a spectral weight proportional to the dopant concentration have been found near the top of the valence band in La1-xSrxMnO3. As the doping level increases, a metal state appears in the ferromagnetic phase, which has a metallic character for one spin subband and an insulating character for the other subband (representing the so-called half-metallic state).
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

16.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Lavrentiev V., Naramoto H., Narumi K., Sakai S., Avramov P.
Заглавие : Planar doping of crystalline fullerene with cobalt
Место публикации : Chemical Physics Letters: Elsevier Science Publishing Company, Inc., 2006. - Т. 423, № 4-6. - С. 366-370. - ISSN 0009-2614, DOI 10.1016/j.cplett.2006.03.087. - ISSN 1873-4448(eissn)
ГРНТИ : 31
РИНЦ,
Читать в сети ИФ
Найти похожие

17.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Petrov M. I., Balaev D. A., Gokhfeld Yu. S., Dubrovskiy A. A., Shaykhutdinov K. A.
Заглавие : Enhancement of pinning in cerium doped Y(1-x)CexBa2Cu3O7HTSC
Разночтения заглавия :авие SCOPUS: Enhancement of pinning in cerium doped Y(1-x)CexBa2Cu3O7 HTSC
Место публикации : Physica C: ELSEVIER SCIENCE BV, 2007. - Vol. 460: 8th International Conference on Materials and Mechanisms of Superconductivity and High Temperature Superconductors (JUL 09-14, 2006, Dresden, GERMANY). - P1192-1193. - ISSN 0921-4534, DOI 10.1016/j.physc.2007.04.046
Примечания : Cited References: 2
Ключевые слова (''Своб.индексиров.''): htsc--ybco--ce doped--flux pinning--ce doped--flux pinning--htsc--ybco--cerium--doping (additives)--flux pinning--lattice constants--magnetization--yttrium compounds--cerium ions--diamagnetic responses--temperature dependence--high temperature superconductors
Аннотация: To test the pinning force in high-temperature superconductors with minor doping, the Y(1-x)CexBa2Cu3O7 system has been synthesized. Temperature dependence of magnetization has been determined. The difference of diamagnetic responses M(zfc) - M(fc) is non-monotonic. It has a peak at a concentration value x = 0.0156, which corresponds to the most probable distance between cerium ions equal to eight lattice constants in the a-b plane and close to the diameter of vortices. (c) 2007 Elsevier B.V. All rights reserved.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

18.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Ivanova N. B., Kazak N. V., Michel C. R., Balaev A. D., Ovchinnikov S. G., Vasil'ev A. D., Bulina N. V., Panchenko E. B.
Заглавие : Effect of strontium and barium doping on the magnetic state and electrical conductivity of GdCoO3
Место публикации : Phys. Solid State: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2007. - Vol. 49, Is. 8. - P1498-1506. - ISSN 1063-7834, DOI 10.1134/S1063783407080161
Примечания : Cited References: 36
Предметные рубрики: PEROVSKITE
ORDER
OXIDE
BEHAVIOR
GLASSES
LACOO3
PR
GD
SM
ND
Аннотация: A coordinated investigation of the magnetic and electrical properties of polycrystalline cobalt oxide compounds CdCoO3, Gd0.9Ba0.1CoO3, and Gd0.9Sr0.1CoO3 is carried out. Undoped GdCoO3 reveals a low conductivity; a magnetic moment of 7.4 mu(B) per molecule, which is less than the theoretical value for the Gd3+ ion; and an asymptotic Curie temperature of -6 K. Doping GdCoO3 with barium and strontium to substitution of 10 at. % Gd brings about an increase in the conductivity and magnetic transitions at T = 300 K for Gd0.9Ba0.1CoO3 and T = 170 K for Gd0.9Sr0.1CoO3. The magnetization anomalies imply the formation of magnetic clusters. The behavior of the electrical conductivity at high temperatures suggests a variable activation energy. At low temperatures, Mott hopping conduction sets in.
WOS,
Scopus,
РИНЦ,
Смотреть статью,
Читать в сети ИФ
Найти похожие

19.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Korshunov M. M., Ovchinnikov S. G.
Заглавие : Doping-dependent evolution of low-energy excitations and quantum phase transitions within an effective model for high-T-c copper oxides
Разночтения заглавия :авие SCOPUS: Doping-dependent evolution of low-energy excitations and quantum phase transitions within an effective model for high-T c copper oxides
Место публикации : Eur. Phys. J. B: SPRINGER, 2007. - Vol. 57, Is. 3. - P271-278. - ISSN 1434-6028, DOI 10.1140/epjb/e2007-00179-2
Примечания : Cited References: 49
Предметные рубрики: ELECTRON CORRELATIONS
HUBBARD-MODEL
RANGE-ORDER
DIMENSIONS
WAVE
FERMIONS
SYSTEMS
BANDS
METAL
Ключевые слова (''Своб.индексиров.''): doping dependent evolution--kinematic correlation functions--low energy excitations--quantum phase transitions--doping (additives)--electric excitation--mean field theory--parameter estimation--phase transitions--quantum theory--copper oxides
Аннотация: In this paper a mean-field theory for the spin-liquid paramagnetic non-superconducting phase of the p- and n-type high-T-c cuprates is developed. This theory applied to the effective t-t'-t ''-J* model with the ab initio calculated parameters and with the three-site correlated hoppings. The static spin-spin and kinematic correlation functions beyond Hubbard-I approximation are calculated self-consistently. The evolution of the Fermi surface and band dispersion is obtained for the wide range of doping concentrations x. For p-type systems the three different types of behavior are found and the transitions between these types are accompanied by the changes in the Fermi surface topology. Thus a quantum phase transitions take place at x = 0.15 and at x = 0.23.Due to the different Fermi surface topology we found for n-type cuprates only one quantum critical concentration, x = 0.2. The calculated doping dependence of the nodal Fermi velocity and the effective mass are in good agreement with the experimental data.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

20.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Berry F. J., Dmitrieva T. V., Ovanesyan N. S., Lyubutin I. S., Thomas M. F., Sarkisyan V. A., Ren X., Aminov T. G., Shabunina G. G., Rudenko V., Vorotynov A. M., Dubinskaya Y. L.
Заглавие : Magnetic order in FeCr2S4-type chalcogenide spinels
Место публикации : J. Phys.: Condens. Matter: IOP PUBLISHING LTD, 2007. - Vol. 19, Is. 26. - Ст.266204. - ISSN 0953-8984, DOI 10.1088/0953-8984/19/26/266204
Примечания : Cited References: 15
Предметные рубрики: COLOSSAL-MAGNETORESISTANCE
TRANSITION
Ключевые слова (''Своб.индексиров.''): doping (additives)--iron compounds--magnetization--magnetoresistance--mossbauer spectroscopy--x ray absorption fine structure spectroscopy--chalcogenide spinels--low temperature magnetic behaviour--magnetic ordering temperature--thiospinels--chalcogenides
Аннотация: The thiospinels of composition FeCr2S4 and Fe1+xCr2-2xSnxS4 with 0 x 0.1 have been examined by means of extended x- ray absorption fine structure, Mossbauer spectroscopy and magnetoresistance techniques. The structural characterization shows that tin enters the spinel- related lattice as Sn4+ and occupies the octahedral B site. Appreciable magnetoresistance is observed in the temperature range 160 - 185 K which includes the magnetic ordering temperature. The effect of slight non- stoichiometry in FeCr2S4 and of tin doping is observed in the M r ossbauer spectra which show the Fe2+ ions to occupy the tetrahedral A sites. The M r ossbauer spectra recorded around the magnetic ordering temperature are sensitive to small ( 0.03 T) applied magnetic fields. The influence of tin on the low temperature magnetic behaviour is associated with the distribution of Cr3+, Sn4+ and Fe3+ ions around tetrahedral Fe2+ sites and vacancies in the anionic sublattice. An interpretation of the colossal magnetoresistance phenomena below TN is suggested.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие