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: (<.>S=ORDER<.>)

Общее количество найденных документов : 27
Показаны документы с 1 по 20

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Аверьянов, Евгений Михайлович
Заглавие : Молекулярно-оптическая и структурная анизотропия нематической смеси Е7
Место публикации : Жидк. крист. и их практич. использ. - 2019. - Т. 19, № 1. - С. 42-51. - ISSN 1991-3966, DOI 10.18083/LCAppl.2019.1.42; Liq. Cryst. Appl. - ISSN 2499–9644
Примечания : Библиогр.: 20
Предметные рубрики: LIQUID
ORDER
POLARIZABILITY
Ключевые слова (''Своб.индексиров.''): нематические смеси--ориентационный порядок нематических смесей--анизотропия локального поля в нематических смесях--свойства молекул в нематических смесях--нематические смеси, ориентационный порядок нематических смесей, анизотропия локального поля в нематических смесях, свойства молекул в нематических смесях--nematic mixtures--orientational order of nematic mixtures--local-field anisotropy in nematic mixtures--molecular properties in nematic mixtures
Аннотация: Для нематической смеси E7 производных цианобифенила исследована связь показателей преломления nj при поляризациях световой волны вдоль (j = ||) и нормально оптической оси (j = ⊥) с параметрами поляризуемости (компонентами γjα, средним значением γmα = (γ||α + 2γ⊥α)/3, анизотропией δγα = γ||α - γ⊥α) и ориентационным порядком молекул типа α, составляющих смесь. Для смеси введен тензор локального поля с компонентами fj =1+Lj(nj2 – 1). Получена связь компонент тензора Лорентца Lj с компонентами Ljα. Температурные зависимости Lj(Т) для смеси Е7 определены с использованием экспериментальных зависимостей nj(λ,Т) от длины световой волны λ. Подтверждена связь Lj(Ljα). Получена температурная зависимость S(Т) материального параметра порядка смеси. Обнаружено изменение среднего значения γm(Т) = ((γ|| + 2γ⊥)/3 для исследованной смеси за счет изменения S(Т). Показано, что зависимость γm(S) обусловлена противоположными по знаку вкладами от изменения конформации бифенильных остовов молекул и межмолекулярных взаимодействий. Полученные результаты сопоставлены со следствиями использования модельных тензоров fj, известных в литературе для смесей.The relation of the refractive indices nj of the nematic mixture E7 consisting of cyanobiphenyl derivatives for the light-wave polarization along (j = ||) and across (j = ⊥) the optical axis with the polarizability parameters (components γjα, mean value γmα = (γ||α + 2γ⊥α)/3, anisotropy δγα = γ||α - γ⊥α) and orientational order of α-type molecules comprising the mixture was investigated. The local-field tensor with components fj =1+Lj(nj2 – 1) was introduced for the mixture and the relationship between the Lorentz-tensor components Lj and the components Ljα was established. The temperature dependences Lj(Т) for the E7 mixture were obtained using experimental dependences nj(λ,T). The relationship Lj(Ljα) was confirmed. The temperature dependence of the material order parameter S(T) was obtained. The change of the mean value γm(Т) = ((γ|| + 2γ⊥)/3 for the studied mixture due to changing of S(Т) was observed. The dependence γm(S) was shown to be caused by two opposite-sign contributions due to changing conformation of molecular biphenyl cores and intermolecular interactions. The obtained results were compared with the consequences of using model tensors fj, which literature data are known for mixtures.
Смотреть статью,
РИНЦ,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Zhandun V. S., Zamkova N. G., Zinenko V. I.
Заглавие : Lattice dynamics, ferroelectric and antiferroeelctric instabilities, and the ferroelectric phase transition in disordered PbB(1/2)' B(1/2)'' O(3) (B ' = Ga, In, Lu; B '' = Nb, Ta) solid solutions
Разночтения заглавия :авие SCOPUS: Lattice dynamics, ferroelectric and antiferroeelctric instabilities, and the ferroelectric phase transition in disordered PbB′ 1/2B″1/2O3 (B′ = Ga, In, Lu; B″ = Nb, Ta) solid solutions
Место публикации : J. Exp. Theor. Phys.: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2008. - Vol. 106, Is. 6. - P1109-1117. - ISSN 1063-7761, DOI 10.1134/S1063776108060101
Примечания : Cited References: 29
Предметные рубрики: STATISTICAL-MECHANICS
PEROVSKITES
CRYSTALS
ORDER
RELAXOR
BATIO3
PBTIO3
Ключевые слова (''Своб.индексиров.''): crystal lattices--ferroelectricity--lattice vibrations--solids--ferroelectric (barium strontium titanate)--ferroelectric phase transitions--lattice (co)--lattice dynamics--vibration spectrum--ferroelectric materials
Аннотация: The lattice vibration spectra, rf permittivity, and dynamic Born charges of disordered PbB(1/2)'B(1/2)'' O(3) (B' = Ga, In, Lu; B '' = Nb, Ta) solid solutions are calculated in terms of the generalized Gordon-Kim model. All the compounds are found to have soft modes related to the center (Gamma(15)) and boundary point R (R(15)) of the Brillouin zone; the frequencies of these modes are close. The ferroelectric phase transition temperatures and the spontaneous polarization in the ferroelectric phase are calculated for the solid solutions using a model Hamiltonian in the local mode approximation and the Monte Carlo method. These temperatures for the tantalum compounds are found to be higher than for the niobium compounds, and temperature t(s) increases with the atomic number of ion B'. A model where the antiferroelectric state is related to the condensation of modes Gamma(15) and R(15) is proposed. It is found that, for all compounds except for PbSc(1/2)Nb(1/2)O(3) and PbSc(1/2)Ta(1/2)O(3), the ferroelectric phase, which is only related to the condensation of mode R(15), and the antiferroelectric phase have similar energies. In PbIn(1/2)Ta(1/2)O(3), the antiferroelectric phase turns out to be energetically favorable.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Sukhinin Y. V.
Заглавие : Ising-like model of tilted phase transitions in Langmuir monolayers
Место публикации : Phys. Rev. B: AMERICAN PHYSICAL SOC, 2006. - Vol. 74, Is. 19. - Ст.195423. - ISSN 1098-0121, DOI 10.1103/PhysRevB.74.195423
Примечания : Cited References: 27
Предметные рубрики: MONTE-CARLO-SIMULATION
FATTY-ACID MONOLAYERS
AIR-WATER-INTERFACE
AMPHIPHILE MONOLAYERS
ROTATOR PHASES
ALKANES
DIAGRAM
POTENTIALS
ORDER
Аннотация: Two Ising models on a rectangular lattice (sigma(1) model and sigma(2) model) linked to three- and four-spin interactions are used to describe the sequence of tilted phase transitions in monolayers of amphiphilic long-chain molecules on an air-water surface. Starting from Morse atom-atom potentials self-consistent equations for basic thermal averages are derived in terms of a mean-field approximation. We employ the model for CH3(CH2)(18)COOH at two values of the molecule density and obtain all known tilted phases, including an intermediate one.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Janoschek M., Fischer P., Schefer J., Roessli B., Pomjakushin V., Meven M., Petricek V., Petrakovskii G. A., Bezmaternykh L. N.
Заглавие : Single magnetic chirality in the magnetoelectric NdFe3((BO3)-B-11)(4)
Разночтения заглавия :авие SCOPUS: Single magnetic chirality in the magnetoelectric NdFe3( 11BO3 )4
Место публикации : Phys. Rev. B: AMER PHYSICAL SOC, 2010. - Vol. 81, Is. 9. - Ст.94429. - ISSN 1098-0121, DOI 10.1103/PhysRevB.81.094429
Примечания : Cited References: 55
Предметные рубрики: NEUTRON-DIFFRACTION
PHASE-TRANSITIONS
SLOW-NEUTRONS
CRYSTAL
NDFE3(BO3)(4)
EXTINCTION
NUCLEAR
ORDER
MNSI
ANTIFERROMAGNETS
Аннотация: We have performed an extensive study of single crystals of the magnetoelectric NdFe3 ((BO3)-B-11)(4) by means of a combination of single-crystal neutron diffraction and spherical neutron polarimetry. Our investigation did not detect significant deviations at low temperatures from space group R32 concerning the chemical structure. With respect to magnetic ordering our combined results demonstrate that in the commensurate magnetic phase below T-N approximate to 30 K all three magnetic Fe moments and the magnetic Nd moment are aligned ferromagnetically in the basal hexagonal plane but align antiferromagnetically between adjacent planes. The phase transition to the low-temperature incommensurate (IC) magnetic structure observed at T-IC approximate to 13.5 K appears to be continuous. By means of polarized neutron studies it could be shown that in the incommensurate magnetic phase the magnetic structure of NdFe3((BO3)-B-11)(4) is transformed into a long-period antiferromagnetic helix with single chirality. Close to the commensurate-incommensurate phase transition third-order harmonics were observed, which in addition indicate the formation of magnetic solitons.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Gorev M. V., Flerov I. N., Tressaud A., Molokeev M. S., Kartashev A. V., Pogoreltsev E. I., Bayukov O. A.
Заглавие : Phase transitions in fluoride KFe2F6 with tetragonal tungsten bronze structure
Коллективы : RFBR [12-02-00056]; Council on Grants from the President of the Russian Federation for the Support of Leading Scientific Schools of the Russian Federation [NSh-924.2014.2]
Место публикации : J. Fluor. Chem.: Elsevier Science, 2014. - Vol. 168. - P.204-211. - ISSN 0022-1139, DOI 10.1016/j.jfluchem.2014.09.031. - ISSN 1873-3328
Примечания : Cited References: 14. - This work was supported by RFBR, project no. 12-02-00056, and the Council on Grants from the President of the Russian Federation for the Support of Leading Scientific Schools of the Russian Federation (grant NSh-924.2014.2).
Предметные рубрики: K3FE5F15
490-K
ORDER
Ключевые слова (''Своб.индексиров.''): tetragonal tungsten bronze structure--phase transition--charge ordering--thermal properties
Аннотация: Heat capacity, thermal dilatation, structure, Mossbauer spectra and dielectric permittivity of fluoride KFe2F6 with tetragonal tungsten bronze crystal structure were studied. The as-made sample undergoes two structural phase transitions P4/mbm (T-1 approximate to 340 K) - Pbam (T-2 approximate to 250 K) - G(2) and magnetic phase transformation at T-m approximate to 133 K. Heating up to 600-700 K and subsequent cooling in helium atmosphere leads to a change of phase transition temperatures and diffused anomalies in thermal expansion. The results obtained and influence of thermal prehistory of the sample on its physical properties are discussed in the context of previous studies on related fluorides KFe2F6, which sometimes suggest conflicting structural details. (C) 2014 Elsevier B.V. All rights reserved.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : GOREV M. V., FLEROV I. N., VORONOV V. N., MISYUL S. V.
Заглавие : P = T-PHASE DIAGRAMS OF ELPASOLITES RB2KB3+F6(B3+ = HO,DY,TB)
Место публикации : Fiz. Tverd. Tela: MEZHDUNARODNAYA KNIGA, 1993. - Vol. 35, Is. 4. - P1022-1027. - ISSN 0367-3294
Примечания : Cited References: 16
Предметные рубрики: RIGID SPHERE MODEL
RB2KMIIIF6 ELPASOLITES
TRANSITIONS
ORDER
WOS
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Martynov S. N., Tugarinov V. I.
Заглавие : Ground state of an antiferromagnet with uniform antisymmetric exchange in a magnetic field
Место публикации : JETP Letters. - 2010. - Vol. 92, Is. 2. - P.115-119. - ISSN 0021-3640, DOI 10.1134/S0021364010140092
Примечания : Cited References: 12
Предметные рубрики: INCOMMENSURATE
TRANSITION
ORDER
Аннотация: A system of two nonlinear differential equations for sublattice angles is proposed to describe the spin orientation distribution in a planar antiferromagnet with uniform antisymmetric exchange in a magnetic field. This system involves the initial symmetry of the problem and is reduced to a single delay differential equation. The solutions of this system are parameterized by the initial condition imposed on the angle of one sublattice at the hyperbolic singular point of the phase space. The numerical analysis of the stability boundary of soliton solutions demonstrates that the transition to the commensurate phase takes place outside the region where the stochastic solutions appear and is accompanied by the magnetization jump Delta m similar to 10(-1) m.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Makarov I. A., Ovchinnikov S. G.
Заглавие : Temperature dependence of the electronic structure of La2CuO4 in the multielectron LDA+GTB approach
Место публикации : J. Exp. Theor. Phys.: MAIK Nauka-Interperiodica / Springer, 2015. - Vol. 121, Is. 3. - P.457-464. - ISSN 1063-7761, DOI 10.1134/S1063776115090174
Примечания : Cited References: 38. - The work was supported by the Russian Science Foundation (project no. 14-12-00061)
Предметные рубрики: Copper oxides
Model
Superconductivity
Excitations
Instability
Spectrum
States
Order
Аннотация: The band structure of La2CuO4 in antiferromagnetic and paramagnetic phases is calculated at finite temperatures by the multielectron LDA+GTB method. The temperature dependence of the band spectrum and the spectral weight of Hubbard fermions is caused by a change in the occupation numbers of local multielectron spin-split terms in the antiferromagnetic phase. A decrease in the magnetization of the sublattice with temperature gives rise to new bands near the bottom of the conduction band and the top of the valence band. It is shown that the band gap decreases with increasing temperature, but La2CuO4 remains an insulator in the paramagnetic phase as well. These results are consistent with measurements of the red shift of the absorption edge in La2CuO4 with increasing temperature. © 2015, Pleiades Publishing, Inc.
Смотреть статью,
Scopus,
WOS,
РИНЦ,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Parshin A. M., Nazarov V. G., Zyryanov V. Ya., Shabanov V. F.
Заглавие : Magnetic-field-induced structural transition in polymer-dispersed liquid crystals
Место публикации : Mol. Cryst. Liquid Cryst. - 2012. - Vol. 557, Is. 1. - P.50-59. - ISSN 1542-1406, DOI 10.1080/15421406.2011.632237
Примечания : Cited References: 19. - This study was supported by the Presidium of the Russian Academy of Sciences (Project no. 24.1) and the Siberian Branch of the Russian Academy of Sciences (grant no. 43).
Предметные рубрики: FRANK CONSTANTS
ELECTRIC-FIELD
NEMATIC DROPS
ANISOTROPY
ALIGNMENT
FILMS
ORDER
Ключевые слова (''Своб.индексиров.''): anchoring energy--magnetic field--polymer-dispersed liquid crystals--structural transition--temperature fluctuations
Аннотация: The structural transition occurring in droplets of nematic liquid crystals formed in a polymer in magnetic field is studied. The transition is caused by field-driven weakening of tangential surface anchoring and develops following two scenarios: bipolar structure/homogeneous structure or bipolar structure/radial structure. The first scenario suggests a cyclic transition occurring upon thermal fluctuations without field. The structural transition is considered within a model of the biaxial liquid crystal/polymer interface. The model describes tendency of the nematic director to align tangentially on a droplet's surface, normally under the action of flexoelectric polarization, and axially along the magnetic-field-imposed easy orientation axis.
Смотреть статью,
Scopus,
WoS,
Читать в сети ИФ
Найти похожие

10.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Balaev D. A., Krasikov A. A., Dubrovskii A. A., Semenov S. V., Bayukov O. A., Stolyar S. V., Iskhakov R. S., Ladygina V. P., Ishchenko L. A.
Заглавие : Magnetic properties and the mechanism of formation of the uncompensated magnetic moment of antiferromagnetic ferrihydrite nanoparticles of a bacterial origin
Коллективы : Ministry of Education and Science of the Russian Federation; Siberian Branch of the Russian Academy of Sciences
Место публикации : J. Exp. Theor. Phys.: Pleiades Publishing, 2014. - Vol. 119, Is. 3. - P.479-487. - ISSN 1063-7761, DOI 10.1134/S1063776114080044. - ISSN 1090-6509
Примечания : Cited References: 42. - This work was supported by the Ministry of Education and Science of the Russian Federation (state contract in 2014-2016) and a program of the Siberian Branch of the Russian Academy of Sciences.
Предметные рубрики: NIO NANOPARTICLES
EXCHANGE BIAS
HYSTERESIS ANOMALIES
FERRITIN
SURFACE
MOSSBAUER
ORDER
SIZE
Аннотация: The magnetic properties of the superparamagnetic ferrihydrite nanoparticles that form as a result of the vital activity of Klebsiella oxytoca bacteria are studied. Both an initial powder with an average number of iron atoms N Fe ∼ 2000–2500 in a particle and this powder after annealing at 140°C for 3 h in air are investigated. The following substantial modifications of the magnetic properties of the ferrihydrite nanoparticles are detected after annealing: the superparamagnetic blocking temperature increases from 23 to 49.5 K, and the average magnetic moment of a particle increases (as follows from the results of processing of magnetization curves). The particles have antiferromagnetic ordering, and the magnetic moment resulting in the superparamagnetism of the system appears due to random spin decompensation inside the particle. For this mechanism, the number of uncompensated spins is proportional to the number of magnetically active atoms raised to the one-half power, and this relation holds true for the samples under study at a good accuracy. The possible causes of the detected shift of magnetic hysteresis loops at low temperatures upon field cooling are discussed.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие

11.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Popova E. A., Vasiliev A. N., Temerov V. L., Bezmaternykh L. N., Tristan N., Klingeler R., Buchner B.
Заглавие : Magnetic and specific heat properties of YFe3(BO3)(4) and ErFe3(BO3)(4)
Коллективы :
Разночтения заглавия :авие SCOPUS: Magnetic and specific heat properties of YFe3(BO3) 4 and ErFe3(BO3)4
Место публикации : J. Phys.: Condens. Matter: IOP PUBLISHING LTD, 2010. - Vol. 22, Is. 11. - Ст.116006. - ISSN 0953-8984, DOI 10.1088/0953-8984/22/11/116006
Примечания : Cited References: 26. - This work was supported by DFG grants 436 RUS and HE 3439/6 (FOR 520). The authors are indebted to M N Popova and B Z Malkin for valuable discussions.
Предметные рубрики: LINEAR-CHAIN ANTIFERROMAGNETISM
CRYSTAL-STRUCTURE
GDFE3(BO3)(4)
MULTIFERROICS
BA2COS3
ORDER
Ключевые слова (''Своб.индексиров.''): antiferromagnetic orders--basal planes--experimental data--magnetically ordered state--antiferromagnetism--calorimetry--erbium--magnetic moments--single crystals--specific heat--magnetic domains
Аннотация: The present paper reports on the specific heat and magnetization of the YFe3(BO3)(4) and ErFe3(BO3)(4) single crystals. In both compounds, antiferromagnetic order of the iron spins evolves at T-N = 38 K. The experimental data suggest that the magnetic moments are in the basal plane of the trigonal crystal for both compounds. In the magnetically ordered state the crystal is subdivided into three types of domains, the magnetic moments of the Fe3+ ions being aligned along the a axis within each domain. For ErFe3(BO3)(4), two non-equivalent magnetic positions of the Er3+ ions in each domain are observed.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

12.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Aleksandrova I. P., Sukhovsky A. A., Ivanov Y. N., Raevsky I. P.
Заглавие : Local structure of disordered PbSc1/2Nb1/2O3 in the region of the diffuse tetragonal phase-rhombohedral phase transition
Место публикации : Phys. Solid State: MAIK Nauka-Interperiodica / Springer, 2012. - Vol. 54, Is. 2. - P.316-323. - ISSN 1063-7834, DOI 10.1134/S1063783412020047
Примечания : Cited References: 16. - This study was supported by the Council on Grants from the President of the Russian Federation for Support of the Leading Scientific Schools of the Russian Federation (grant no. NSh-4645.2010.2).
Предметные рубрики: Neutron-diffraction
Order
BaTiO3
PbNiO3
NMR
Аннотация: The local structure of the ferroelectric-relaxor PbSc1/2Nb1/2O3 in the temperature range from 550 to 220 K has been investigated using 45Sc nuclear magnetic resonance. It has been found that, in the paraelectric phase at temperatures below 550 K, the crystal consists of regions of an ordered elpasolite structure and inclusions of the disordered tetragonal perovskite phase with displacements along directions of the [001] type. The relative weight of the tetragonal structure in the region of the paraelectric phase is approximately equal to 0.28. Below the temperature of the phase transition from the disordered modification to the polar phase, the relative weight of the tetragonal phase decreases with decreasing temperature. The tetragonal structure is replaced by the trigonal polar structure. In a wide temperature range (∼50 K), there exists a heterophase structure that is characteristic of relaxors. Note that the correlation length of displacements in the tetragonal phase should be very small to explain the absence of indications of the existence of this phase in the diffraction data.
Смотреть статью,
Читать в сети ИФ
Найти похожие

13.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Krakhalev M. N.
Заглавие : Oblique light incidence method to study topological defects in nematic layers with conical boundary conditions
Место публикации : Sci. Rep. - 2021. - Vol. 11, Is. 1. - Ст.17433. - ISSN 2045-2322, DOI 10.1038/s41598-021-96784-9
Примечания : Cited References: 54
Предметные рубрики: CHOLESTERIC FINGERS
DISCLINATIONS
SURFACE
WALLS
ORDER
Аннотация: A polarization microscopy method to investigate the orientational structures and boojums formed in the chiral and achiral nematic layers under conical (tilted) boundary conditions has been developed. Oblique light incidence on nematic layer is used, due to which the phase difference between the ordinary and extraordinary waves depends on the director’s azimuthal angle. The phase difference gets maximal when the director azimuthal angle of achiral nematic φ(x,y)=0 and an azimuthal angle at the center of the chiral nematic layer φ0(x,y)=0 independently of the total twist angle φTOTAL. It has been found that the m=+1 boojums with the phase ξ=±90° and ξ=(−90°+φTOTAL/2) are formed in achiral and chiral nematics, respectively, at the director tilt angle θd/2≅40° at the interface. In addition, the defectless structure of chiral nematic with the periodically variable azimuthal director angle on the substrates has been studied.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие

14.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Korshunov M. M., Eremin I.
Заглавие : Theory of magnetic excitations in iron-based layered superconductors
Место публикации : Phys. Rev. B: AMER PHYSICAL SOC, 2008. - Vol. 78, Is. 14. - Ст.140509. - ISSN 1098-0121, DOI 10.1103/PhysRevB.78.140509
Примечания : Cited References: 31
Предметные рубрики: NEUTRON-SCATTERING
INSTABILITY
STATE
ORDER
MODEL
Аннотация: Based on the effective four-band model we analyze the spin response in the normal and superconducting states of the Fe-pnictide superconductors. While the normal-state spin excitations are dominated by the continuum of the interorbital antiferromagnetic fluctuations and the intraband spin-density wave fluctuations, the unconventional superconductivity yields different feedback. The resonance peak in the form of the well-defined spin exciton occurs only for the interband scattering at the antiferromagnetic momentum Q(AFM) for the s(+/-) (extended s wave) superconducting order parameter and it disappears rapidly for q Q(AFM). The resonance feature is extremely weak for the d(x)(2)-y(2)-wave order parameter due to the specific Fermi-surface topology of these compounds. The essential difference between s(+/-)-wave and d(x)(2)-y(2)-wave symmetries for the magnetic excitations can be used for experimental determination of the superconducting wave-function symmetry.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

15.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Korshunov M. M., Eremin I.
Заглавие : Doping evolution of itinerant magnetic fluctuations in Fe-based pnictides
Коллективы :
Место публикации : Europhys. Lett. - 2008. - Vol. 83, Is. 6. - Ст.67003. - ISSN 0295-5075, DOI 10.1209/0295-5075/83/67003
Примечания : Cited References: 18. - We would like to thank B. BUCHNER, S.-L. DRECHSLER, D. EFREMOV, P. FULDE, I. MAZIN, R. MOESSNER and D. PARKER for useful discussions. IE acknowledges support from Volkswagen Foundation.
Предметные рубрики: SUPERCONDUCTIVITY
ORDER
Аннотация: Employing the four-band tight-binding model, we study theoretically the doping dependence of the spin response in the normal state of novel Fe-based pnictide superconductors. We show that the commensurate spin density wave (SDW) transition that arises due to interband scattering between the hole alpha-pockets and the electron beta-pockets disappears already at the doping concentration x approximate to 0.04 reflecting the evolution of the Fermi surfaces. Correspondingly, with further increase of the doping the antiferromagnetic fluctuations are suppressed for x 0.1 and the imaginary part of the spin susceptibility at antiferromagnetic wave vector becomes nearly temperature independent. At the same time, we observe that the uniform susceptibility deviates from the Pauli-like behavior and is increasing with increasing temperature reflecting the activation processes for the alpha-Fermi surfaces up to temperatures of about T = 800 K. With increase of the doping the absolute value of the uniform susceptibility lowers and its temperature dependence changes. In particular, it is a constant at low temperatures and then decreases with increasing temperature. We discuss our results in a context of recent experimental data. Copyright (C) EPLA, 2008
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

16.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Myagkov V. G., Zhigalov V. S., Bykova L. E., Bondarenko G. N., Rybakova A. N., Matsynin A. A., Tambasov I. A., Volochaev M. N., Velikanov D. A.
Заглавие : High rotatable magnetic anisotropy in epitaxial L10CoPt(111) thin films
Место публикации : JETP Letters. - 2015. - Vol. 102, Is. 6. - P.355-360. - ISSN 00213640 (ISSN), DOI 10.1134/S0021364015180101
Примечания : Cited References: 51. - A We are grateful to L.A. Solov'ev for the help in X-ray studies of the epitaxial orientation of phases in L10CoPt(111) samples. This work was supported by the Russian Foundation for Basic Research (project no. 15-02-00948), in part by the Council the President of the Russian Federation for Support of Young Scientists and Leading Scientific Schools (project no. SP-317.2015.1), and by the Foundation for the Assistance of the Development of Small Innovative Scientific and Engineering Enterprises (UMNIK).
Предметные рубрики: Co-Pt ALLOYS
ROOM-TEMPERATURE
COERCIVITY
ORIGIN
ORDER
STATE
Аннотация: The evolution of the structural and magnetic properties in epitaxial film systems Co/Pt(111) of equiatomic composition during vacuum annealing has been presented. Annealing to the temperature of 400°C does not lead to the variation of the structural and magnetic properties of the films, which indicates the absence of considerable mixing of the Co/Pt interface. With the increase in the annealing temperature from 400 to 750°C, nanoclusters containing the main magnetically hard L10CoPt(111) phase epitaxially intergrown with the CoPt3 phase are formed. High rotatable magnetic anisotropy has been found in the prepared films. In magnetic fields above the coercive force (H > HC = 8 kOe), the easy anisotropy axis with the angle of lag taken into account can be oriented in any spatial direction. Possible mechanisms of the formation of the rotatable magnetic anisotropy have been discussed. It has been assumed that the high rotatable magnetic anisotropy makes the main contribution to the magnetic perpendicular anisotropy in CoxPt1–x films. © 2015, Pleiades Publishing, Inc.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие

17.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Fedoseev A. D.
Заглавие : Realization conditions and the magnetic field dependence of corner excitations in the topological insulator with superconducting coupling on the triangular lattice
Коллективы : Russian Foundation for Basic Research, Government of Krasnoyarsk Territory [19-02-00348]; Krasnoyarsk Regional Fund of Science [20-42-243005]; "Coulomb interactions in the problem of Majorana modes in low-dimensional systems with nontrivial topology" [19-42-240011]; Council of the President of the Russian Federation for Support of Young Scientists and Leading Scientific SchoolsLeading Scientific Schools Program [MK1641.2020.2]
Место публикации : J. Exp. Theor. Phys. - 2021. - Vol. 133, Is. 1. - P.71-76. - ISSN 1063-7761, DOI 10.1134/S1063776121060029. - ISSN 1090-6509(eISSN)
Примечания : Cited References: 38. - This work was supported by the Russian Foundation for Basic Research (project no. 19-02-00348), Government of Krasnoyarsk Territory, Krasnoyarsk Regional Fund of Science to the research projects: "Study of edge states in oneand two-dimensional topological superconductors" (no. 20-42-243005), "Coulomb interactions in the problem of Majorana modes in low-dimensional systems with nontrivial topology" (no. 19-42-240011), and Council of the President of the Russian Federation for Support of Young Scientists and Leading Scientific Schools (Project MK1641.2020.2)
Предметные рубрики: EDGE
STATES
ORDER
Аннотация: The studies of the topological properties of systems have recently been extended due to a new concept of higher-order topological insulators and superconductors. Many models were proposed for two-dimensional systems on a square lattice, where corner excitations can appear; however, the problem of existence of such excitations in superconducting systems with a triangular crystal lattice is still poorly understood. Using a topological insulator in the form of a triangle with a chiral superconducting order parameter as an example, we shows that corner excitations can exist in C3-symmetric systems. In spite of a nontopological character, these excitations have energies inside the gap of the first-order edge excitation spectrum over a wide parameter range and are well localized at the corners of the system. Gapless corner excitations are shown to exist in the system at certain parameters. The application of a magnetic field in the system plane removes the triple degeneracy of the corner excitation energy and makes it possible to control the position of the minimum-energy corner excitation using a magnetic field. At the same time the fine adjustment to achieve the gapless excitations at the chosen corner can be made with changing of the magnetic field value.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие

18.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Aver'yanov E. M., Gunyakov V. A., Korets A. Y., Akopova O. B.
Заглавие : Experimental solution of the local-field problem in discotic liquid crystals
Место публикации : JETP Letters. - 1999. - Vol. 70, Is. 1. - P.29-35. - ISSN 0021-3640, DOI 10.1134/1.568125
Примечания : Cited References: 14
Предметные рубрики: ORDER
Аннотация: Polarized light-absorption spectra are obtained for single-domain planar-oriented samples of the discotic D-ho. Previously predicted spectral effects induced by resonant dipole-dipole interactions of the molecules are observed. New methods for determining the parameters of the local field in the D-ho phase are developed which take into account the mixing of the molecular excitations. It is shown that the two-dimensional crystalline ordering of the molecular columns decreases the anisotropy of the local field for this phase. (C) 1999 American Institute of Physics. [S0021-3640(99)00613-1].
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

19.

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

20.

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