Главная
Авторизация
Фамилия
Пароль
 

Базы данных


Труды сотрудников ИФ СО РАН - результаты поиска

Вид поиска

Область поиска
в найденном
Формат представления найденных документов:
полный информационныйкраткий
Отсортировать найденные документы по:
авторузаглавиюгоду изданиятипу документа
Поисковый запрос: (<.>S=EVOLUTION<.>)
Общее количество найденных документов : 17
Показаны документы с 1 по 17
1.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : PARLINSKI K., CURRAT R., VETTIER C., ALEKSANDROVA I. P., ECKOLD G.
Заглавие : Effect of hydrostatic-pressure on modulated phases in Rb2ZnBr4
Разночтения заглавия :авие SCOPUS: Effect of hydrostatic pressure on modulated phases in Rb2ZnBr4
Место публикации : Phys. Rev. B. - 1992. - Vol. 46, Is. 1. - P.106-114. - ISSN 0163-1829, DOI 10.1103/PhysRevB.46.106
Примечания : Cited References: 36
Предметные рубрики: INCOMMENSURATE PHASES
NEUTRON-SCATTERING
X-RAY
COMMENSURATE
TRANSITIONS
EVOLUTION
MODEL
WAVE
Аннотация: Neutron-diffraction studies on modulated Rb2ZnBr4, carried out under hydrostatic pressure, revealed two new commensurate phases characterized by wave vectors q = 2/7b* and q = 1/4b*, respectively. The first order phase transition between them is revealed by the coexistence of two distinct peaks in the diffraction pattern. The observed pressure-temperature phase diagram contains: the above-mentioned phases, the ferroelectric commensurate phase q = 1/3, and a region characterized by wave-vector values in the interval q = 2/7-1/3. In this region the modulation wave vector exhibits stepwise behavior as a function of pressure, but remains nearly constant iii temperature runs. We have found in this region a characteristic memory effect in which two temperature runs performed at the same pressure lead to two different modulation wave-vector values, while only the thermal history of the sample is different in the two runs. At ambient pressure we confirm the presence of a multipeaked diffraction pattern just above the lock-in transition to the commensurate q = 1/3 phase. At 122 K the phase transition from the 1/3 phase to the 1/4 phase is detected in pressure scans. The transition mechanism involves the q = 2/7 phase, at least as a metastable intermediate phase.
WOS,
Scopus
Найти похожие
2.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Gavrichkov V. A., Borisov A. A., Ovchinnikov S. G.
Заглавие : Polarized ARPES spectra of undoped cuprates
Место публикации : Phys. Solid State: AMER INST PHYSICS, 2001. - Vol. 43, Is. 10. - P1876-1884. - ISSN 1063-7834, DOI 10.1134/1.1410625
Примечания : Cited References: 15
Предметные рубрики: ELECTRONIC-STRUCTURE
COPPER OXIDES
PHOTOEMISSION
EVOLUTION
MODEL
HOLE
Аннотация: The spectral density (SD) in the ARPES spectra of anti ferromagnetic (AFM) dielectrics Sr2CuO2Cl2 and Ca2CuO2Cl2 along the principal symmetry directions of the Brillouin zone was studied by the generalized tight binding method. At the valence band top of these undoped cuprates in the AFM state, there is a pseudogap of magnetic nature with E-s(k) similar to 0-0.4 eV between a virtual level and the valence band proper. The observed similarity of dispersion along the Gamma -M and X-Y directions can be explained by the proximity of the B-3(1g) triplet and the Zhang-Rice singlet levels. The value of parity of the polarized ARPES spectra at the Gamma, M, and X points calculated for the AFM phase of undoped cuprates with an allowance for the partial contributions is even. The conditions favoring observation of the partial contributions in polarized ARPES spectra are indicated. Due to the spin fluctuations, the virtual level acquires dispersion and possesses a small spectral weight. Probably, this level cannot be resolved on the background of the main quasi-particle peak as a result of the damping effects. (C) 2001 MAIK "Nauka/Interperiodica".
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
3.

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
4.

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
5.

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
6.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Korshunov M. M., Zakharova E. V., Nekrasov I. A., Pchelkina Z. V., Ovchinnikov S. G.
Заглавие : The Fermi surface and the role of electronic correlations in Sm2-xCexCuO4
Коллективы :
Разночтения заглавия :авие SCOPUS: The Fermi surface and the role of electronic correlations in Sm 2-xCexCuO4
Место публикации : J. Phys.: Condens. Matter: IOP PUBLISHING LTD, 2010. - Vol. 22, Is. 1. - Ст.15701. - ISSN 0953-8984, DOI 10.1088/0953-8984/22/1/015701
Примечания : Cited References: 35. - We would like to thank A A Kordyuk and I Eremin for useful discussions. The authors acknowledge support from RFBR (grants 08-02-00021, 10-02-00662, 08-02-91200 and 07-02-00226), the RAS programs on 'Low temperature quantum phenomena', 'Quantum physics of condensed matter' and 'Strongly correlated electrons solids', President of Russia (grants MK-614.2009.2 (IN) and MK-3227.2008.2 (ZP)), Scientific School (grant SS-1929.2008.2), Interdisciplinary UB-SB RAS project, Dynasty Foundation (ZP) and Russian Science Support Foundation (IN).
Предметные рубрики: T-C SUPERCONDUCTOR
IN-GAP STATES
SPIN CORRELATIONS
BAND
LA2-XSRXCUO4
EXCITATIONS
TRANSITION
EVOLUTION
SM2CUO4
OXIDES
Ключевые слова (''Своб.индексиров.''): antiferromagnetics--doping evolution--electron-doped--electronic correlation--emery model--experimental data--generalized tight bindings--high-t--hybrid scheme--magnetic orders--spin-liquid--tight binding model--two-regime--antiferromagnetism--cerium--cerium compounds--copper oxides--corundum--doping (additives)--fermi surface--fermions--tin--surfaces
Аннотация: Using a LDA + GTB (local density approximation + generalized tight-binding) hybrid scheme we investigate the band structure of the electron-doped high-T-c material Sm2-xCexCuO4. Parameters of the minimal tight-binding model for this system (the so-called three-band Emery model) were obtained within the NMTO (Nth-order muffin-tin orbital) method. The doping evolution of the dispersion and the Fermi surface in the presence of electronic correlations was investigated in two regimes of magnetic order: short-range (spin-liquid) and long-range (antiferromagnetic metal). Each regime is characterized by the specific topologies of the Fermi surfaces and we discuss their relation to recent experimental data.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
7.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Ovchinnikov S. G., Nikolaev S. V.
Заглавие : Calculation of the Fermi Surface with Complex Topology from Norm-Conserving Cluster Perturbation Theory for Doping Dependent Electronic Structure of the Hubbard Model
Место публикации : JETP Letters. - 2011. - Vol. 93, Is. 9. - P.517-520. - ISSN 0021-3640, DOI 10.1134/S0021364011090116
Примечания : Cited References: 27. - This work was supported by the Presidium of the Russian Academy of Sciences (program no. 18.7); the Russian Foundation for Basic Research (project nos. 09-02-00127, 10-02-90725-mob_st); Siberian Branch, Russian Academy of Sciences (Integration Project no. N40); and the Ministry of Education and Sciences of the Russian Federation (state contract no. P891, Program "Kadry").
Предметные рубрики: QUANTUM OSCILLATIONS
SUPERCONDUCTORS
EVOLUTION
Аннотация: The results of recently developed norm-conserving cluster perturbation theory for doping dependent electronic structure of the Hubbard model are reported. We have found that the momentum distribution of the spectral weight strongly depends on the broadening value delta. At delta = 0.1t, we reproduce the angle-resolved photoemission spectroscopy data, while at delta = 0.01t we obtain two quantum phase transitions. DOI: 10.1134/S0021364011090116
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
8.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Nikolaev S. V., Ovchinnikov S. G.
Заглавие : Effect of hole doping on the electronic structure and the Fermi surface in the Hubbard model within norm-conserving cluster pertubation theory
Место публикации : J. Exp. Theor. Phys.: MAIK Nauka-Interperiodica / Springer, 2012. - Vol. 114, Is. 1. - P.118-131. - ISSN 1063-7761, DOI 10.1134/S1063776111150143
Примечания : Cited References: 51. - This study was supported financially by the Russian Foundation for Basic Research (project nos. 10-02-90725-mob_st and 09-02-00127), Program 18.7 of the Presidium of the Russian Academy of Sciences, the Federal Target Program "Personnel" (state contract no. P891), and the integrated project no. 40 of the Siberian Branch of the Russian Academy of Sciences.
Предметные рубрики: HIGH-TEMPERATURE SUPERCONDUCTORS
NARROW ENERGY-BANDS
CORRELATED ELECTRONS
PSEUDOGAP
EVOLUTION
La2-XSRXCuO4
INSULATOR
Аннотация: The concentration dependences of the band structure, spectral weight, density of states, and Fermi surface in the paramagnetic state are studied in the Hubbard model within cluster pertubation theory with 2 x 2 clusters. Representation of the Hubbard X operators makes it possible to control conservation of the spectral weight in constructing cluster perturbation theory. The calculated value of the ground-state energy is in good agreement with the results obtained using nonperturbative methods such as the quantum Monte Carlo method, exact diagonalization of a 4 x 4 cluster, and the variational Monte Carlo method. It is shown that in the case of hole doping, the states in the band gap (in-gap states) lie near the top of the lower Hubbard band for large values of U and near the bottom of the upper band for small U. The concentration dependence of the Fermi surface strongly depends on hopping to second (t') and third (t '') neighbors. For parameter values typical of HTSC cuprates, the existence of three concentration regions with different Fermi surfaces is demonstrated. It is shown that broadening of the spectral electron density with an energy resolution typical of contemporary ARPES leads to a pattern of arcs with a length depending on the concentration. Only an order-of-magnitude decrease in the linewidth makes it possible to obtain the true Fermi surface from the spectral density. The kinks associated with strong electron correlations are detected in the dispersion relation below the Fermi level.
Смотреть статью,
Scopus,
WoS,
РИНЦ,
Читать в сети ИФ
Найти похожие
9.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Lykhin A. O., Novikova G. V., Kuzubov A. A., Staloverova N. A., Sarmatova N. I., Varganov S. A., Krasnov P. O.
Заглавие : A complex of ceftriaxone with Pb(II): synthesis, characterization, and antibacterial activity study
Коллективы : RFBR [14-03-31, 170 MOJI_a]
Место публикации : J. Coord. Chem.: Taylor & Francis, 2014. - Vol. 67, Is. 16. - З2783-2794. - ISSN 0095-8972, DOI 10.1080/00958972.2014.938065. - ISSN 1029-0389
Примечания : Cited References: 48. - The reported study was supported by RFBR, research project No. 14-03-31, 170 MOJI_a and Krasnoyarsk regional fund for supporting scientific and technological activities. We thank the Center for Equipment Joint Use of the Siberian Federal University. We are grateful to the HPC Research Departments of Siberian Federal University and Moscow University Supercomputing Center (SKIF MSU "Chebyshev") for the access to the high-performance computer clusters.
Предметные рубрики: BETA-LACTAM ANTIBIOTICS
TERNARY COMPLEX
METAL-COMPLEXES
BASIS-SETS
3 DECADES
RESISTANCE
COPPER(II)
CEPHALOSPORINS
EVOLUTION
1ST-ROW
Ключевые слова (''Своб.индексиров.''): ceftriaxone lead(ii) complex--dft--ir spectroscopy--tga--antibacterial screening
Аннотация: A Pb(II) complex with ceftriaxone (H2Ceftria) antibiotic was synthesized by reaction of ceftriaxone disodium salt (hemi)heptahydrate with lead nitrate in water–ethanol medium. The complex was characterized on the basis of complexometric titration, spectrophotometric and thermogravimetric analyses, capillary electrophoresis, IR, Raman and UV–vis spectroscopies, and density functional theory calculations. Pb(II) is five-coordinate with distorted square pyramidal geometry. The coordination of Ceftria2− to Pb(II) occurs through N and O of the triazine, lactam carbonyl, carboxylate, and amine groups. The antibacterial activity study showed that Klebsiella pneumoniae is resistant to [Pb(Ceftria)]·3H2O. The antibacterial activity of [Pb(Ceftria)]·3H2O against Staphylococcus aureus is reduced compared with ceftriaxone. In contrast, the antibacterial activity of [Pb(Ceftria)]·3H2O against Escherichia coli is 28% higher than that of ceftriaxone antibiotic.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие
10.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Krinitsyn A., Nikolaev S., Ovchinnikov S. G.
Заглавие : Cluster size and shape effect on the electronic structure of the Hubbard model within the norm-conserving cluster perturbation theory
Коллективы : Siberian Federal University [F-11]; Presidium of RAS Program [20.7]; [NSh-1044.2012.2]; [MK-1168.2012.2]
Место публикации : J. Supercond. Nov. Magn.: Springer, 2014. - Vol. 27, Is. 4. - P.955-963. - ISSN 1557-1939, DOI 10.1007/s10948-013-2418-7. - ISSN 1557-1947
Примечания : Cited References: 59. - This work was supported by Grants NSh-1044.2012.2 and MK-1168.2012.2, Siberian Federal University: Grant F-11, and the Presidium of RAS Program 20.7.
Предметные рубрики: NARROW ENERGY-BANDS
CUPRATE SUPERCONDUCTORS
PHOTOEMISSION SPECTRA
PSEUDOGAP
ANTIFERROMAGNET
EXCITATIONS
EVOLUTION
SYSTEMS
PHASE
STATE
Ключевые слова (''Своб.индексиров.''): cluster perturbation theory--hubbard model--strong correlations--density of states--fermi surface
Аннотация: Within a new norm-conserving approach to the cluster perturbation theory (CPT) for the 2d Hubbard model we study the effect of the cluster size and shape on the electronic structure. We have compared two type of clusters, 4-cluster (2x2) and 5-cluster (cruciform of 5 atoms). With 4-cluster we can treat exactly the first and second neighbours correlations, C (1) and C (2). With 5-cluster the third neighbour correlations C (3) are also treated exactly. The band structure in the CPT with 4- and 5-clusters differs remarkably. The quasiparticle spectral weight map for 5-clusters is very similar to the Quantum Monte Carlo (QMC) and the variational CPT data. With increasing doping, small hole Fermi surface transforms into conventional Fermi-liquid type large Fermi surface through Lifshitz quantum phase transitions.
Смотреть статью,
Scopus,
WoS,
Читать в сети ИФ
Найти похожие
11.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Bataleva, Yu. V., Palyanov, Yu. N., Borzdov, Yu. M., Bayukov O. A., Sobolev N. V.
Заглавие : Interaction of iron carbide and sulfur under P–T conditions of the lithospheric mantle
Коллективы : Russian Foundation for Basic Research [14-05-31061], Council for Grants and Support of the Leading Scientific Schools of the President of the Russian Federation [NSh 2024.2014.5]
Место публикации : Dokl. Earth Sci.: MAIK Nauka-Interperiodica / Springer, 2015. - Vol. 463, Is. 1. - P.707-711. - ISSN 1028-334X, DOI 10.1134/S1028334X15070077
Примечания : This study was supported by the Russian Foundation for Basic Research (project no. 14-05-31061) and by the Council for Grants and Support of the Leading Scientific Schools of the President of the Russian Federation (NSh 2024.2014.5).
Предметные рубрики: MINERAL INCLUSIONS
DIAMOND
CARBON
EVOLUTION
CORES
Аннотация: Experimental studies were performed in the Fe3C–S system at P = 6.3 GPa, T = 900–1600°C, and t = 18–20 h. The study aimed to characterize the conditions of iron carbide stability in a reduced lithospheric mantle and to reveal the possibility of the formation of elemental carbon by the interaction of iron carbide and sulfur. It was found that the reaction at T 1200°C proceeds with the formation of a pyrrhotite–graphite assemblage by the following scheme: 2Fe3C + 3S2 → 6FeS + 2C0. The crystallization of graphite at T 1200°C is accompanied by the generation of sulfide and metal–sulfide melts and via 2Fe3C + 3S2 → 6[Fe–S(melt) + Fe–S–C(melt)] + 2C(graphite)0 reaction. Resulting from the carbon-generating reactions, not only graphite crystallized in sulfide or metal–sulfide melts, but the growth of diamond also takes place. The obtained data allow one to consider cohenite as a potential source of carbon in the processes of diamond and graphite crystallization under the conditions of a reduced lithospheric mantle. The interaction of iron carbide and sulfur under which carbon extraction proceeds may be one of possible processes of the global carbon cycle. © 2015, Pleiades Publishing, Ltd
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие
12.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Iskhakov R. S., Komogortsev S. V., Balaev A. D., Gavriliuk A. A.
Заглавие : The manifestations of the two-dimensional magnetic correlations in the nanocrystalline ribbons Fe64CO21B15
Место публикации : J. Magn. Magn. Mater.: Elsevier Science, 2015. - Vol. 374. - P.423-426. - ISSN 0304-8853, DOI 10.1016/j.jmmm.2014.08.078. - ISSN 1873-4766
Примечания : Cited References: 42
Предметные рубрики: GRAIN-SIZE DEPENDENCE
RANDOM ANISOTROPY
AMORPHOUS-ALLOYS
COERCIVE FORCE
FERROMAGNETS
FILMS
SATURATION
Fe
MICROSTRUCTURE
EVOLUTION
Ключевые слова (''Своб.индексиров.''): magnetic correlations--nanoclystalline alloys--random magnetic anisotropy--coercivity
Аннотация: We report and discuss the grain size dependence of the coercivity and approach magnetization to saturation in the FeCoB ribbons. Instead of expected three-dimensional magnetic correlations for 20 mu m thick ribbon with grain size about 10 nm, the observed behavior could be attributed to the two-dimensional stochastic magnetic domains and two dimensional magnetization ripple. (C) 2014 Elsevier B.V. All rights reserved.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие
13.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Ma L., Xia Z., Atuchin V. V., Molokeev M. S., Auluck S., Reshak A. H., Liu Q.
Заглавие : Engineering oxygen vacancies towards self-activated BaLuAlxZn4-xO7-(1-x)/2 photoluminescent materials: An experimental and theoretical analysis
Место публикации : Phys. Chem. Chem. Phys.: Royal Society of Chemistry, 2015. - Vol. 17, Is. 46. - P.31188-31194. - ISSN 14639076 (ISSN), DOI 10.1039/c5cp05130d
Примечания : Cited References: 28. - The present work was supported by the National Natural Science Foundations of China (Grant No. 51572023, 51272242 and 51511130035), and Fundamental Research Funds for the Central Universities (FRF-TP-15-005A1). The author A. H. Reshak would like to acknowledge the CENTEM project, reg. no. CZ.1.05/2.1.00/03.0088, cofunded by the ERDF as part of the Ministry of Education, Youth and Sports OP RDI programme and, in the follow-up sustainability stage, supported through CENTEM PLUS (LO1402) by financial means from the Ministry of Education, Youth and Sports under the National Sustainability Programme I. Computational resources were provided by MetaCentrum (LM2010005) and CERIT-SC (CZ.1.05/3.2.00/08.0144) infrastructures. SA would like to thank CSIR-NPL and Physics Department IIT Delhi for financial support. This work was partly supported by the Russian Foundation for Basic Research (Grant No. 15-52-53080 GFEN_a). VVA was partly supported by the Ministry of Education and Science of the Russian Federation.
Предметные рубрики: PHOSPHOR
LUMINESCENCE
EVOLUTION
OXIDES
IONS
Аннотация: Novel self-activated yellow-emitting BaLuAlxZn4-xO7-(1-x)/2 photoluminescent materials were investigated by a combined experimental and theoretical analysis. The effects of Al/Zn composition modulation, calcination atmosphere and temperature on the crystal structure and photoluminescence properties have been studied via engineering oxygen vacancies. Accordingly, BaLuAl0.91Zn3.09O7 prepared in an air atmosphere was found to be the stable crystalline phase with optimal oxygen content and gave a broad yellow emission band with a maximum at 528 nm. The self-activated luminescence mechanism is ascribed to the O-vacancies based on the density functional theory (DFT) calculation. A theoretical model originating from the designed oxygen vacancies has been proposed in order to determine the influence of O-vacancies on the band structure and self-activated luminescence. Therefore, the appearance of a new local energy level in the band gap will cause the wide-band optical transitions in the studied BaLuAlxZn4-xO7-(1-x)/2 materials.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие
14.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Pichugin K. N., Sadreev A. F.
Заглавие : Frequency comb generation by symmetry-protected bound state in the continuum
Коллективы : Russian Foundation for Basic Research (RFBR) [03-02-00497]
Место публикации : J. Opt. Soc. Am. B: Optical Society of America, 2015. - Vol. 32, Is. 8. - P.1630-1636. - ISSN 0740, DOI 10.1364/JOSAB.32.001630. - ISSN 15208540(eISSN)
Примечания : Cited References:48. - Russian Foundation for Basic Research (RFBR) (03-02-00497).
Предметные рубрики: RADIATION CONTINUUM
DIMER
MICRORESONATOR
EVOLUTION
CAVITIES
BREAKING
EQUATION
Аннотация: We study the dynamical response of two nonlinear microresonators coupled with a photonic crystal waveguide. We find a domain in the space of frequency and amplitude of the probing light where all stationary solutions are unstable. In this domain, scattered light carries multiple harmonics with equidistantly spaced frequencies [frequency comb (FC) effect]. Two identical resonators coupled with the waveguide support the symmetry-protected bound state in the continuum whose response is singular, as the amplitude of the injected wave tends to zero. As a result, the FC interval tends to zero when the amplitude of probing light diminishes, which paves the way for all-optical generation of waves with ultralow frequency. (C) 2015 Optical Society of America
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие
15.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Xia Z., Miao S., Molokeev M. S., Chen M., Liu Q.
Заглавие : Structure and luminescence properties of Eu2+ doped LuxSr2-xSiNxO4-x phosphors evolved from chemical unit cosubstitution
Место публикации : J. Mater. Chem. C: Royal Society of Chemistry, 2016. - Vol. 4, Is. 6. - P.1336-1344. - ISSN 20507534 (ISSN), DOI 10.1039/c5tc04222d
Примечания : Cited References: 32. - This work was supported by the National Natural Science Foundation of China (Grant No. 51572023 and 51272242), the Program for New Century Excellent Talents in University of Ministry of Education of China (NCET-12-0950), Beijing Nova Program (Z131103000413047), the Funds of the State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, CAS (RERU2015022), and Fundamental Research Funds for the Central Universities (FRF-TP-15-003A2).
Предметные рубрики: SOLID-SOLUTION PHOSPHORS
WHITE-LIGHT
PHOTOLUMINESCENCE
SUBSTITUTION
DISCOVERY
TRANSITIONLEDS
EVOLUTION
HOST
LEDS
Аннотация: The design scheme of the chemical unit cosubstitution of [Lu3+-N3-] for [Sr2+-O2-] in Sr2SiO4:Eu2+ has been put into practice to discover the new phosphor systems with tunable luminescence properties, and the structures and photoluminescence tuning of yellow-emitting LuxSr2-xSiNxO4-x:Eu2+ phosphors have been investigated. Crystal structures of LuxSr2-x-ySiNxO4-x:yEu2+ samples were resolved using the Rietveld method, suggesting that the as-prepared Sr2SiO4 belonged to monoclinic symmetry (P21/n) of β-phase Sr2SiO4, while Sr1.97Eu0.03SiO4 and Sr1.965Eu0.03Lu0.005SiO3.995N0.005 belonged to orthorhombic symmetry (Pnma) of α-Sr2SiO4. The emission peaks of LuxSr1.97-xSiNxO4-x:0.03Eu2+ phosphors were red-shifted from 563 to 583 nm upon increasing the [Lu3+-N3-] substitution content from x = 0 to x = 0.005, furthermore, the PL emission peaks of Lu0.005Sr1.965-ySiN0.005O3.995:yEu2+ also showed a red-shift from 583 nm to 595 nm with increasing Eu2+ concentration (y = 0.03, 0.07, 0.10 and 0.15), and their corresponding red-shift mechanism has been discussed. The temperature dependent luminescence results further verified that the introduction of [Lu3+-N3-] for [Sr2+-O2-] in Sr2SiO4:Eu2+ can improve the thermal stability of the photoluminescence, which indicated that the LuxSr2-x-ySiNxO4-x:yEu2+ phosphors have potential applications in white light-emitting diodes (wLEDs). © 2016 The Royal Society of Chemistry.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие
16.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Kuz’min V. I., Nikolaev S. V., Ovchinnikov S. G.
Заглавие : Influence of varying magnetic order in an external magnetic field on the electronic structure and Fermi surface within the t–J model
Место публикации : JETP Letters. - 2016. - Vol. 103, Is. 2. - P.125-130. - ISSN 00213640 (ISSN), DOI 10.1134/S0021364016020089
Примечания : Cited References: 46. - This work was supported by the Russian Science Foundation (project no. 14-12-00061).
Предметные рубрики: C copper oxides
Quantum oscillations
Cuprate superconductors
Hubbard-model
Temperature
Excitations
YBa2Cu3OY
Evolution
Phase
Аннотация: We investigate the electronic structure of the two-dimensional t–J model in a transverse external static magnetic field with canted long-range magnetic order using cluster perturbation theory. The distribution of the spectral weight in the whole range of fields from zero to ferromagnetic saturation is explored. We demonstrate the possibility of a sharp change in a distribution of spectral weight at the Fermi level associated with the magnetic correlations when varying magnetic field.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие
17.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Ji, Haipeng, Cho, Yujin, Wang, L.e., Hirosaki, Naoto, Molokeev M. S., Huang, Zhaohui, Xie, Rong-Jun
Заглавие : Phase formation of (Y,Ce)2BaAl4SiO12 yellow microcrystal-glass phosphor for blue LED pumped white lighting
Место публикации : Ceram. Int.: Elsevier Science, 2017. - Vol. 43, Is. 8. - P.6425-6429. - ISSN 0272-8842, DOI 10.1016/j.ceramint.2017.02.055. - ISSN 1873-3956(eISSN)
Примечания : Cited References:12. - This study was partially supported by the National Natural Science Foundations of China (Grants No. 51272259, 51572232 and 51561135015). R.X. was partially supported by the JSPS KAKENHI (No. 15K06448). M.M. was partially supported by the Russian Foundation for Basic Research (Grant No. 15-52-53080) H.J. thanks the China Scholarship Council (CSC) for scholarship support.
Предметные рубрики: LUMINESCENCE
EVOLUTION
Ключевые слова (''Своб.индексиров.''): phosphor--wled--photoluminescence--cathodoluminescence
Аннотация: The (Y,Ce)2BaAl4SiO12 phosphor, a garnet-structured blue-to-yellow color convertor for WLED, exhibits an interesting “microcrystal-glass powder” feature, which can be regarded as the 4th form for phosphor, in addition to the “ceramic powder phosphor”, the “single crystal phosphor” and the “glass-ceramic phosphor”. The structure exhibits luminescent microcrystals embedding in non-luminescent glass matrix: the spherical crystals are mainly arranged around the glass phase forming a “necklace” pattern, while the individual crystals show a “core-shell” architecture regarding the luminescence intensity variation. Further combining the phase evolution evidence evaluated by Rietveld refinement, we propose the formation mechanism for such unique morphology/structure as a two-stage process, including an initial nucleation by solid state reaction and following liquid-assisted crystal growth, instead of a precipitation-crystallization process.
Смотреть статью,
WOS,
Читать в сети ИФ
Найти похожие
 

Другие библиотеки

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