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=TRANSITIONS<.>)

Общее количество найденных документов : 44
Показаны документы с 1 по 20

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Dudnikov V. A., Ovchinnikov S. G., Orlov Yu.S., Kazak N. V., Michel C. R., Patrin G. S., Yurkin G.Yu.
Заглавие : Contribution of Co3+ ions to the high-temperature magnetic and electrical properties of GdCoO3
Место публикации : J. Exp. Theor. Phys.: MAIK Nauka-Interperiodica / Springer, 2012. - Vol. 114, Is. 5. - P.841-849. - ISSN 1063-7761, DOI 10.1134/S106377611203003X
Примечания : Cited References: 28. - This work was supported by the Ural Branch of the Russian Academy of Sciences and Siberian Branch of the Russian Academy of Sciences (project no. 40), the Russian Foundation for Basic Research (project nos. 09-02-00171-a, 10-02-00251), program 2.3 of the Department of Physical Sciences of Russian Academy of Sciences, and Nonprofit Dinastiya Foundation.
Предметные рубрики: SPIN-STATE
RCOO3 R
TRANSITIONS
COBALTITES
LACOO3
OXIDES
SM
EU
ND
Аннотация: The temperature dependence of the static magnetization of polycrystalline rare-earth cobaltite GdCoO3 is measured in the temperature range 2-800 K. The magnetic behaviors of GdCoO3 and Gd3+ are found to be different at temperatures above room temperature, which is caused by the appearance of a contribution from Co3+ ions at high temperatures. The temperature dependence of the magnetic susceptibility of GdCoO3 is determined by the magnetization of rare-earth gadolinium ions and the additional paramagnetic contribution induced by the thermally excited magnetic terms of Co3+ ions. The LDA + GTB method is used to calculate the electronic structure of GdCoO3 in the temperature range 0-300 K with allowance for strong electron correlations. The energy spectrum of GdCoO3 is found to have intragap states that decrease the dielectric gap width with increasing temperature.
Смотреть статью,
Scopus,
WoS,
РИНЦ,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Malakhovskii A. V., Sukhachev A. L., Leont'ev A. A., Gudim, I. A., Krylov A. S., Aleksandrovsky A. S.
Заглавие : Spectroscopic properties of Nd0.5Gd0.5Fe3(BO3)4 single crystal
Место публикации : J. Alloys Compd.: Elsevier, 2012. - Vol. 529. - P.38-43. - ISSN 0925-8388, DOI 10.1016/j.jallcom.2012.03.066
Примечания : Cited References: 51. - The work was supported by the Russian Foundation for Basic Researches grant 12-02-00026, by the Russian President Grants SS-1044.2012.2 and SS-4828.2012.2, by Ministry of Education and Science of Russian Federation (Contract 16.740.11.0150), by grant no. SFU.F12 and by Projects No. 28, 43 and No. 101 of SB RAS.
Предметные рубрики: SPECTRAL-LINE INTENSITIES
RARE-EARTH IONS
MAGNETIC-PROPERTIES
NDAL3(BO3)(4) NAB
OPTICAL-SPECTRA
LASER CRYSTAL
TRANSITIONS
ABSORPTION
ND3+
PR3+
Ключевые слова (''Своб.индексиров.''): magnetically ordered materials--rare earth alloys and compounds--transition metal alloys and compounds--optical properties
Аннотация: The polarized absorption spectra of trigonal single crystal Nd0.5Gd0.5Fe3(BO3)4 were measured in the spectral range 10,000–22,000 cm−1. The d–d and f–f transitions spectra were separated. The f–f transitions intensities were analyzed in terms of the Judd–Ofelt theory in a ferroborate with huntite structure for the first time, and the following parameters of the theory were obtained: Ω2 = 4.4 × 10−20 cm2, Ω4 = 8.04 × 10−20 cm2, and Ω6 = 8.25 × 10−20 cm2. The strengths, spontaneous emission probabilities, branching ratios, spectroscopic quality factor and excited state lifetime were calculated for transitions from the 4F3/2 state to 4IJ manifold. All the obtained spectroscopic characteristics were compared with those of alumoborates with the same crystal structure.
Смотреть статью,
Scopus,
WoS,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Slyusareva E. A., Tomilin F. N., Sizykh A. G., Tankevich E. Y., Kuzubov A. A., Ovchinnikov S. G.
Заглавие : The effect of halogen substitution on the structure and electronic spectra of fluorone dyes
Место публикации : Opt. Spectrosc.: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2012. - Vol. 112, Is. 5. - P.671-678. - ISSN 0030-400X, DOI 10.1134/S0030400X12040194
Примечания : Cited References: 44. - This work was supported by the FTsP Kadry GK-P333 and by the Siberian Branch of the Russian Academy of Sciences (Integration project no. 2). We are grateful to the Joint Supercomputer Center of the Russian Academy of Sciences (Moscow) and to the Complex of High-Performance Computations of the IKIT of Siberian Federal University. E. A. Slyusareva acknowledges support from the German Academic Exchange Service and the Ministry of Education and Science of the Russian Federation (the program "Mikhail Lomonosov II") of scientific research at the University of Regensburg and in the Helmholtz Center in Berlin (Germany).
Предметные рубрики: POLARIZABLE CONTINUUM MODEL
BORIC-ACID GLASS
XANTHENE DYES
FLUORESCEIN DERIVATIVES
DELAYED FLUORESCENCE
EOSIN-Y
ABSORPTION
PHOSPHORESCENCE
TRANSITIONS
EXCITATION
Аннотация: By means of the B3LYP density functional method with the use of the polarized continuum model PCM, we have performed quantum-chemical computations of the electronic absorption and fluorescence spectra of fluorone dianions: fluorescein, dibromofluorescein, eosin, erythrosine, and Rose Bengal in vacuum and methanol. We have revealed conformational features of the structure of fluorone dianions (charge redistribution, changes in the bond lengths and angles between bonds) second by the halogen substitution, the transition from the ground state to an excited state, and the change of the solvent (vacuum-methanol). Absorption and fluorescence wavelengths, constant dipole moments, transition dipole moments, and oscillator strengths have been calculated. We have showed that, upon halogenation of fluorones, the absorption spectra are redshifted and the Stokes shift decreases, which is qualitatively consistent with experimental results.
Смотреть статью,
Scopus,
WoS,
Читать в сети ИФ
Найти похожие

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

Вид документа : Статья из сборника (однотомник)
Шифр издания :
Автор(ы) : Arkhipkin V. G., Timofeev I. V.
Заглавие : Propagation of two short pulses under conditions of electromagnetically induced transparency: adiabatic following
Коллективы : International Workshop/Fall School Meeting for Young Scientists and Students on Optics, Laser Physics, and Biophysics (Saratov Fall Meeting 99) (1999 ; Oct.; Saratov)
Место публикации : Saratov fall meeting '99: Laser physics and spectroscopy. Ser. Proceedings of the society of photo-optical instrumentation engineers (SPIE): SPIE-Int. Soc. Optical Engineering, 2000. - Vol. 4002. - P.45-51. - ISBN 0277-786X, DOI 10.1117/12.380132. - ISBN 0-8194-3627-5
Примечания : Cited References: 31
Предметные рубрики: POPULATION TRANSFER
LASER-PULSES
QUANTUM
COHERENCE
MEDIA
INDEX
INTERFERENCE
ENHANCEMENT
TRANSITIONS
REFRACTION
Ключевые слова (''Своб.индексиров.''): electromagnetically-induced transparency--coherent population trapping--atomic coherence--quantum interference--adiabatic following--dressed field pulses
Аннотация: Spatio-temporal dynamics of two short laser pulses propagating in an absorbing medium, which consists of one-and two-photon resonant ii-atoms, is investigated in the adiabatic approximation. We give an analytical solution and compare it with numerical simulations. It is shown that pulses may propagate in a medium, whose thickness is considerably greater than the length of the linear absorption of a single weak probe wave. Finally, full transfer of the probe pulse energy into the coupling pulse takes place. A vector model of the adiabatic interaction of two pulses with three-level atom is proposed.
WOS,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Safonov I. N., Misyul' S. V., Molokeev M. S., Ivliev M. P.
Заглавие : Structural transformations and phenomenological description of the formation of phase states in elpasolites Cs2RbDyF6 and Rb2KB′F6 (B′ = Ho, Dy, Tb)
Коллективы : Ministry of Education and Science of the Russian Federation [3.2534.2014/K]
Место публикации : Phys. Solid State: MAIK Nauka-Interperiodica / Springer, 2015. - Vol. 57, Is. 3. - P.491-498. - ISSN 1063, DOI 10.1134/S1063783415030282. - ISSN 10906460(eISSN)
Примечания : Cited References:20. - This study was supported by the Ministry of Education and Science of the Russian Federation within the framework of the State Task for the Russian Siberian Federal University for Implementation of Scientific Research Work in 2014 (assignment no. 3.2534.2014/K).
Предметные рубрики: TRANSITIONS
CRYSTALS
Аннотация: The structures of the cubic and monoclinic phases of an Rb2KHoF6 crystal from a series of elpasolites Rb2KB′F6 (B′ = Ho, Dy, Tb), which undergoes a trigger phase transition, have been investigated using X-ray powder diffraction. The critical and noncritical displacements of atoms in the Rb2KHoF6 structure have been determined from the group-theoretical analysis of the complete condensate of order parameters. It has been reliably established that a change in the symmetry due to the phase transition in this crystal can be represented in the form Fmˉ3m11−9(Γ+4)⊕10−3(X+3)(ϕ,ϕ,ψ)P121/n1Fm\bar 3m\frac{{11 - 9(\Gamma _4. + ) \oplus 10 - 3(X_3. + )}} {{(\phi ,\phi ,\psi )}}P12_1 /n1 . A phenomenological analysis of the conditions responsible for the formation of phase states upon the phase transitions in elpasolites Cs2RbDyF6 and Rb2KB′F6 (B′ = Ho, Dy, Tb) has been carried out. Taking into account the structural data and using the phenomenological theory, it has been found that the main factor determining the formation of phase states in these and related crystals is the instability of the elpasolite structure with respect to rotational distortions of two types. It has been shown that an important role in the formation of a sequence of structural transformations in these crystals is played by the interaction of rotational order parameters and displacements of the cation from the center of a cuboctahedral hole.
Смотреть статью,
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Pogoreltsev E. I., Flerov I. N., Kartashev A. V., Bogdanov E. V., Laptash N. M.
Заглавие : Heat capacity, entropy, dielectric properties and T–p phase diagram of (NH4)3TiF7
Коллективы : Russian Foundation for Basic Research [15-02-02009]; 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.247-250. - ISSN 0022-1139, DOI 10.1016/j.jfluchem.2014.10.016. - ISSN 1873-3328
Примечания : Cited References: 16. - This work was supported by the Russian Foundation for Basic Research (Grant no. 15-02-02009), and the Council on Grants from the President of the Russian Federation for the Support of Leading Scientific Schools of the Russian Federation (Grant no. NSh-924.2014.2).
Предметные рубрики: CRYSTAL-STRUCTURE
TRANSITIONS
FLUORIDES
NH4F
Ключевые слова (''Своб.индексиров.''): cubic fluorides--phase transitions--dielectric--phase diagram--calorimetry
Аннотация: Successive phase transitions G1 -- G2 -- G3 in the double salt (NH4)(3)TiF7 have been studied by detailed calorimetric, DTA under hydrostatic pressure and dielectric measurements. Rather large entropy jumps at phase transition points were found to be followed by large additional contributions associated with the temperature dependence of the excess heat capacity. The permittivity behaviour and the tangent of the dielectric losses proved the nonferroelectric nature of both transformations. Two triple-points were found on the temperature-pressure phase diagram, suggesting the existence of a hypothetical parent G0 = Pm-3m cubic phase. A direct transformation between high (G0) and low (G3) temperature cubic phases takes place at p 0.41 GPa with a baric coefficient dT(G0) -- (G3)/dp = -40 K/GPa. (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) : Boldyrev K. N., Pisarev R. V., Bezmaternykh L. N., Popova M. N.
Заглавие : Antiferromagnetic dichroism in a complex multisublattice magnetoelectric CuB2O4
Коллективы : Russian Academy of Sciences under the Programs for Basic Research; Russian Federation [MK-3521.2015.2], Russian Foundation for Basic Research [15-32-20613, 15-02-04222], Ministry of Education and Science of the Russian Federation [14.B25.0031.25]
Место публикации : Phys. Rev. Lett.: American Physical Society, 2015. - Vol. 114, Is. 24. - Ст.247210. - ISSN 0031, DOI 10.1103/PhysRevLett.114.247210. - ISSN 10797114(eISSN)
Примечания : Cited References:40. - This study was supported by the Russian Academy of Sciences under the Programs for Basic Research, by the President of the Russian Federation (Grant No. MK-3521.2015.2, K. N. B.), by the Russian Foundation for Basic Research (Grants No. 15-32-20613, K. N. B., and No. 15-02-04222, R. V. P.), and by the Ministry of Education and Science of the Russian Federation (Grant No. 14.B25.0031.25, R. V. P.).
Предметные рубрики: MAGNETIC SOLITON LATTICE
COPPER METABORATE
GYROTROPIC BIREFRINGENCE
SPECTROSCOPY
EXCITATIONS
TRANSITIONS
CRYSTALS
Cr2O3
FIELD
Аннотация: Magnetic control of the crystal chirality was announced by Saito et al. [Phys. Rev. Lett. 101, (2008)] on the ground of experiments in CuB2O4. This claim has raised a sharp dispute in the literature because it seemed to contradict the fundamental symmetry principles. We settle this dispute on the basis of a high-resolution optical spectroscopy study of excitonic transitions in CuB2O4. We find that a large sublattice-sensitive antiferromagnetic linear dichroism (LD) emerges at the Néel temperature TN=21 K and show how it could simulate a “magnetic-field control of the crystal chirality.” We prove that the discovered LD is related microscopically to the magnetic Davydov splitting. This LD is highly sensitive to subtle changes in the spin subsystems, which allowed us to observe a splitting of the phase transition into an incommensurate magnetic phase into two transitions (T∗1=8.5 and T∗2=7.9 K) and to suggest elliptical spiral structures below T∗1, instead of a simple circular helix proposed earlier.О магнитном контроле кристаллической хиральности сообщил Сайто и др. [Phys. Rev. Lett. 101, 117402 (2008)] на основании экспериментов в CuB2O4. Это требование вызвало резкий спор в литературе, потому что это казалось, противоречат основным принципам симметрии. Мы урегулировать этот спор на основе исследования с помощью оптической спектроскопии высокого разрешения экситонных переходов в CuB2O4. Мы считаем, что большой подрешетко-чувствительный антиферромагнитный линейный дихроизм (LD) возникает при температуре Нееля TN= 21 Kи показываем, как это может имитировать "контроль магнитным полем кристаллической хиральности." Мы докажем, что обнаруженный LD связанс микроскопическим магнитным Давыдовским расщеплением. Этот Л.Д. весьма чувствителен к тонким изменениям в спиновых подсистем, которые позволили нам наблюдать расщепление фазового перехода в несоизмеримы магнитная фаза в двух переходов (T*1= 8,5 и Т*2 = 7,9 К) и предположить эллиптическую спиральную структуру ниже T*1, вместо простой круговой спирали предложенный ранее.
Смотреть статью,
Scopus,
WOS,
Смотреть статью,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Mel'nikova S. V., Laptash N. M.
Заглавие : Optical studies of the (T-x) phase diagram of oxyfluoride (NH4)2MoO2F4-Rb2MoO2F4 solid solutions
Коллективы : Russian Federation [NSh-924.2014.2]
Место публикации : Phys. Solid State: MAIK Nauka-Interperiodica / Springer, 2015. - Vol. 57, Is. 6. - P.1201-1205. - ISSN 1063, DOI 10.1134/S1063783415060256. - ISSN 10906460(eISSN)
Примечания : Cited References:8. - This study was supported by the Council on Grants from the President of the Russian Federation for Supporting of Leading Scientific Schools of the Russian Federation (grant NSh-924.2014.2).
Предметные рубрики: TRANSITIONS
(NH4)2WO2F4
CRYSTALS
DISORDER
Аннотация: Single crystals of solid solutions (NH4)2 − x Rb x MoO2F4 (including individual complex Rb2MoO2F4) have been grown and studied using polarization-optical methods. The birefringence Δn(T) has been measured in the temperature range of 100–400 K. The complete (T-x) phase diagram has been constructed.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие

10.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Xia, Zhiguo, Ma C., Molokeev M. S., Liu Q., Rickert K., Poeppelmeier K. R.
Заглавие : Chemical unit cosubstitution and tuning of photoluminescence in the Ca2(Al1-xMgx)(Al1-xSi1+x)O7:Eu2+ phosphor
Место публикации : J. Am. Chem. Soc.: American Chemical Society, 2015. - Vol. 137, Is. 39. - P.12494-12497. - ISSN 0002-7863, DOI 10.1021/jacs.5b08315
Примечания : Cited References: 24. - This work was supported by the National Natural Science Foundations of China (Grant Nos. 51572023 and 51272242), Natural Science Foundations of Beijing (2132050), the Program for New Century Excellent Talents in University of Ministry of Education of China (NCET-12-0950), Beijing Nova Program (Z131103000413047), and the Funds of the State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, CAS (RERU2015022). C.M. acknowledges financial support from National Natural Science Foundation of China (Grant No. 11204393), Natural Science Foundation Project of Chongqing (Grant No. CSTC2014JCYJA50034), and National Training Programs of Innovation and Entrepreneurship for Undergraduates (Grant No. 201410617001). K.R. recognizes that this material is based upon work supported by the National Science Foundation Graduate Research Fellowship Program under Grant No. DGE-1324585.
Предметные рубрики: LUMINESCENCE PROPERTIES
TRANSITIONS
IONS
Аннотация: The union of structural and spectroscopic modeling can accelerate the discovery and improvement of phosphor materials if guided by an appropriate principle. Herein, we describe the concept of chemical unit cosubstitution as one such potential design scheme. We corroborate this strategy experimentally and computationally by applying it to the Ca2(Al1-xMgx)(Al1-xSi1+x)O7:Eu2+ solid solution phosphor. The cosubstitution is shown to be restricted to tetrahedral sites, which enables the tuning of luminescent properties. The emission peaks shift from 513 to 538 nm with a decreasing Stokes shift, which has been simulated by a crystal-field model. The correlation between the 5d crystal-field splitting of Eu2+ ions and the local geometry structure of the substituted sites is also revealed. Moreover, an energy decrease of the electron-phonon coupling effect is explained on the basis of the configurational coordinate model. © 2015 American Chemical Society.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие

11.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Loiko V. A., Zyryanov V. Ya., Konkolovich A. V., Miskevich A. A.
Заглавие : Light transmission of polymer-dispersed liquid crystal layer composed of droplets with inhomogeneous surface anchoring
Место публикации : Opt. Spectrosc.: MAIK Nauka-Interperiodica / Springer, 2016. - Vol. 120, Is. 1. - P.143-152. - ISSN 0030-400X, DOI 10.1134/S0030400X16010112. - ISSN 1562-6911(eISSN)
Примечания : Cited References:43. - This work was supported by the National Academy of Sciences of Belarus and the Siberian Branch of the Russian Academy of Sciences (project no. 36) and the Belarusian Republican Foundation for Fundamental Research (project no. F15SO-039).
Предметные рубрики: NEMATIC DROPLETS
IONIC MODIFICATION
FIELD
TRANSITIONS
SCATTERING
PARTICLES
INTERFACE
DISPLAYS
Аннотация: We have developed a model and realized an algorithm for the calculation of the coefficient of coherent (direct) transmission of light through a layer of liquid crystal (LC) droplets in a polymer matrix. The model is based on the Hulst anomalous diffraction approximation for describing the scattering by an individual particle and the Foldy-Twersky approximation for a coherent field. It allows one to investigate polymer dispersed LC (PDLC) materials with homogeneous and inhomogeneous interphase surface anchoring on the droplet surface. In order to calculate the configuration of the field of the local director in the droplet, the relaxation method of solving the problem of minimization of the free energy volume density has been used. We have verified the model by comparison with experiment under the inverse regime of the ionic modification of the LC-polymer interphase boundary. The model makes it possible to solve problems of optimization of the optical response of PDLC films in relation to their thickness and optical characteristics of the polymer matrix, sizes, polydispersity, concentration, and anisometry parameters of droplets. Based on this model, we have proposed a technique for estimating the size of LC droplets from the data on the dependence of the transmission coefficient on the applied voltage.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие

12.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Fokina V. D., Bovina A. F., Bogdanov E. V., Pogorel'tsev E. I., Laptash N. M., Gorev M. V., Flerov I. N.
Заглавие : Specific heat, cell parameters, phase T-p diagram, and permittivity of cryolite (NH4)(3)Nb(O-2)(2)F-4
Разночтения заглавия :авие SCOPUS: Specific heat, cell parameters, phase T-p diagram, and permittivity of cryolite (NH4)3Nb(O2)2F4
Место публикации : Phys. Solid State: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2011. - Vol. 53, Is. 10. - P2147-2153. - ISSN 1063-7834, DOI 10.1134/S1063783411100131
Примечания : Cited References: 19. - This study was performed within the Interdisciplinary integration project of the Siberian Branch of the Russian Academy of Science no. 34 and supported by the grant of the President of the Russian Federation for Leading Scientific Schools of the Russian Federation (NSh-4645.2010.2).
Предметные рубрики: CRYSTAL-STRUCTURES
TRANSITIONS
(NH4)(3)TIOF5
OXYFLUORIDE
COMPLEXES
CAPACITY
DISORDER
Аннотация: The temperature dependences of the specific heat, unit cell parameters, susceptibility to hydrostatic pressure, and permittivity of cryolite (NH4)(3)Nb(O-2)(2)F-4 have been studied. Phase transitions of nonferroelectric nature have been detected. Entropy parameters point to the relation of structure distortions to ordering processes.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

13.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Pogorel'tsev E. I., Bogdanov E. V., Molokeev M. S., Voronov V. N., Isaenko L. I., Zhurkov S. A., Laptash N. M., Gorev M. V., Flerov I. N.
Заглавие : Thermodynamic Properties and Structure of Oxyfluorides Rb(2)KMoO(3)F(3) and K(2)NaMoO(3)F(3)
Разночтения заглавия :авие SCOPUS: Thermodynamic properties and structure of oxyfluorides Rb2KMoO3F3 and K2NaMoO3F3
Место публикации : Phys. Solid State: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2011. - Vol. 53, Is. 6. - P1202-1211. - ISSN 1063-7834, DOI 10.1134/S1063783411060266
Примечания : Cited References: 24. - This study was supported by the Siberian Branch of the Russian Academy of Sciences within the framework of the Interdisciplinary Integration project no. 34 SO RAN and the Council on Grants from the President of the Russian Federation for Support of Leading Scientific Schools of the Russian Federation (project no. NSh-4645-2010.2).
Предметные рубрики: T PHASE-DIAGRAM
HEAT-CAPACITY
TRANSITIONS
(NH4)(3)MOO3F3
(NH4)(3)TIOF5
(NH4)(3)WO3F3
RB2KTIOF5
CRYSTALS
CRYOLITE
DISORDER
Аннотация: According to the results of calorimetric and structural studies, the Fm (3) over barm phase in K(2)NaMoO(3)F(3) remains stable at least to 100 K. No ferroelectric transformation assumed earlier has been revealed in a series of Rb(2)KMoO(3)F(3) samples prepared using various technologies. Only a phase transition of nonferroelectric origin has been observed near 195 K, and its thermodynamic characteristics have been determined. An analysis of the stability of the cubic structure of molybdenum fluorine-oxygen elpasolites-cryolites has been performed in the framework of the hypothesis on strengths of interatomic bonds. The barocaloric effect in Rb(2)KMoO(3)F(3) has been estimated.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

14.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Gorev M. V., Bogdanov E. V., Flerov I. N., Kocharova A. G., Laptash N. M.
Заглавие : Investigation of thermal expansion, phase diagrams, and barocaloric effect in the (NH4)(2)WO2F4 and (NH4)(2)MoO2F4 oxyfluorides
Коллективы :
Разночтения заглавия :авие SCOPUS: Investigation of thermal expansion, phase diagrams, and barocaloric effect in the (NH4)2WO2F4 and (NH4)2MoO2F4 oxyfluorides
Место публикации : Phys. Solid State: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2010. - Vol. 52, Is. 1. - P167-175. - ISSN 1063-7834, DOI 10.1134/S1063783410010294
Примечания : Cited References: 27. - This study was performed within the framework of the Interdisciplinary Integration Project no. 34 of the Siberian Branch of the Russian Academy of Sciences and supported by the Krasnoyarsk Regional Science Foundation and the Russian Foundation for Basic Research within the framework of the project "Sibir'" ( grant no. 09-02-98001) and by the Council on Grants from the President of the Russian Federation for the Support of Leading Scientific Schools ( project no. NSh-1011.2008.2).
Предметные рубрики: TRANSITIONS
CRYSTALS
DIFFRACTION
MECHANISM
PRESSURE
Аннотация: The thermal expansion along the principal crystallographic axes of the (NH4)(2)WO2F4 and (NH4)(2)MoO2F4 oxyfluorides has been studied. The anomalous behavior of alpha (i) (T) due to the phase transitions has been revealed at T (1) = 271.4 K and T (2) a parts per thousand 180 K for the molybdate and at T (1) = 201.5 K and T (2) a parts per thousand 161 K for the tungstate. The quantities dT/dp and dT/d sigma (i) , which characterize the dependence of the phase transition temperatures on the hydrostatic and uniaxial pressures, have been determined from analyzing the results of studies of the thermal expansion and heat capacity with the use of the Pippard relations. The p-T and alpha (i) -T phase diagrams reflect different characters of the influence of the pressure on the stability of the initial and distorted phases of the oxyfluorides. The magnitudes of the extensive and intensive barocaloric effects determined in the vicinity of the structural phase transitions are as follows: Delta S (BCE) varies from approximately -10 to -17 J/mol K and Delta T (AD) a parts per thousand 8-17 K for the molybdate and Delta S (BCE) varies from approximately -10 to -17 J/mol K and Delta T (AD) a parts per thousand 8-13 K for the tungstate.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

15.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Fokina V. D., Flerov I. N., Molokeev M. S., Pogoreltsev E. I., Bogdanov E. V., Krylov A. S., Bovina A. F., Voronov V. N., Laptash N. M.
Заглавие : Heat capacity, p-T phase diagram, and structure of Rb2KTiOF5
Коллективы :
Разночтения заглавия :авие SCOPUS: Heat capacity, p-T phase diagram, and structure of Rb2KTiOF 5
Место публикации : Phys. Solid State: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2008. - Vol. 50, Is. 11. - P2175-2183. - ISSN 1063-7834, DOI 10.1134/S1063783408110280
Примечания : Cited References: 23. - This work was supported by the Russian Foundation for Basic Research, project no. 06-02-16102.
Предметные рубрики: ELECTRON-DIFFRACTION
TRANSITIONS
OXYFLUORIDES
(NH4)(2)KWO3F3
TEMPERATURE
XRD
CS
Ключевые слова (''Своб.индексиров.''): 61--50--ks--65--40--ba--65--40--gd--78--30--hv--81--30--dz
Аннотация: Elpasolite Rb2KTiOF5 (space group, Fm was synthesized using a solid-phase reaction method. The temperature dependences of the heat capacity, the unit cell parameters, the structure, the permittivity, the response to an external pressure, and the Raman spectra were studied. A nonferroelectric phase transition was revealed at T (0) = 215 K; the transition is accompanied by a tetragonal distortion of the unit cell (space group I4/m, Z = 10) and a change in the entropy (S (0) = Rln8), which is anomalously large for perovskite-like oxyfluorides with atomic cations. The specific features of the mechanism of structure distortion are discussed in combination with the previous experimental data obtained for cryolite (NH4)(3)TiOF5 and elpasolite Rb2KGaF6.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

16.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Zyryanov V. Y., Krakhalev M. N., Prishchepa O. O., Shabanov A. V.
Заглавие : Orientational structure transformations caused by the electric-field-induced ionic modification of the interface in nematic droplets
Разночтения заглавия :авие SCOPUS: Orientational structure transformations caused by the electric-field- induced ionic modification of the interface in nematic droplets
Место публикации : JETP Letters. - 2007. - Vol. 86, Is. 6. - P.383-388. - ISSN 0021-3640, DOI 10.1134/S0021364007180087
Примечания : Cited References: 18
Предметные рубрики: LIQUID
TRANSITIONS
FILMS
Аннотация: The films of a polymer-dispersed nematic liquid crystal doped with an ionic surfactant were studied. The surface-anchoring modification effect caused by the local increase in the concentration of surface-active ions was observed at the polymer-liquid crystal interface under the action of an electric field. The modification of the boundary conditions leads to the transformation of the orientational structure of the nematic droplets and, as a result, to an appreciable change in their texture patterns and light-scattering efficiency at the interfaces. The monopolar director configurations (normal and curved) arising in the process of orientational structure transformations are considered and their typical textures are demonstrated. The possibility that the monopolar structure can be formed is theoretically substantiated by the computer simulation of the director field in a nematic droplet with the boundary conditions corresponding to the experiment.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

17.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Aplesnin S. S.
Заглавие : Effect of bond fluctuations on the transport properties of manganites and nickelates
Место публикации : J. Exp. Theor. Phys.: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2007. - Vol. 104, Is. 5. - P766-774. - ISSN 1063-7761, DOI 10.1134/S1063776107050111
Примечания : Cited References: 26
Предметные рубрики: NEUTRON-DIFFRACTION
CHARGE DISPROPORTIONATION
ELECTRONIC-STRUCTURE
MAGNETIC ORDER
TRANSITIONS
PEROVSKITES
PRNIO3
GAP
Ключевые слова (''Своб.индексиров.''): crystal structure--manganites--optimization--thermal conductivity--thermal effects--bond fluctuations--nickelates--orthorhombic crystal structure--nickel compounds
Аннотация: For the manganites RMnO(3) (R = La, Pr, Nd), a mechanism is proposed to explain the anomalous temperature dependences of the kinetic coefficients, resistivity, and thermoelectric power during the transition from the pseudocubic O to the orthorhombic O' crystal structure. The contributions of the bending and stretching modes of the octahedron to the formation of thermal-conductivity maxima and to the deviation from the linear dependence of ln(rho/T) on 1/T at low temperatures have been estimated. In nickelates, the metal-insulator transition is caused by lattice-polaron pinning by the stretching mode of the octahedron, and the low-temperature anomaly of the thermal conductivity is related to electron scattering by the bending mode of the octahedron.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

18.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Malakhovskii A. V., Sokolov A. E., Sukhachev A. L., Temerov V. L., Stolbovaya N. A., Edelman I. S.
Заглавие : Magnetic circular dichroism and optical absorption in TmAl3(BO3)(4)
Разночтения заглавия :авие SCOPUS: Magnetic circular dichroism and optical absorption in TmAl 3(BO3)4
Место публикации : Phys. Solid State: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2007. - Vol. 49, Is. 1. - P34-38. - ISSN 1063-7834, DOI 10.1134/S1063783407010076
Примечания : Cited References: 19
Предметные рубрики: SINGLE-CRYSTALS
SPECTROSCOPY
TRANSITIONS
HUNTITE
GROWTH
Аннотация: The polarized spectra of absorption and magnetic circular dichroism in a TmAl3(BO3)(4) single crystal are studied in the re-ion of H-3(6) - F-3(4), H-3(6) - F-3(3),and H-3(3) - F-3(2) electronic transitions in e Tm3+ ion. The structure of the spectra is interpreted qualitatively. It is shown that the magnetic circular dichroism of the H-3(6) - F-3(4) transition is determined by the contribution from the splitting of the ground state, whereas the magnetic circular dichroism of the H-3(6) - F-3(3) transition is governed by the contribution from the splitting of an excited state in a trigonal crystal field.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

19.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Flerov I. N., Gorev M. V., Fokina V. D., Bovina A. F., Molokeev M. S., Pogorel'tsev E. I., Laptash N. M.
Заглавие : Heat capacity, structure, and p-T phase diagram of elpasolite (NH4)(2)KMoO3F3
Разночтения заглавия :авие SCOPUS: Heat capacity, structure, and p-T phase diagram of elpasolite (NH 4)2KMoO3F3
Место публикации : Phys. Solid State: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2007. - Vol. 49, Is. 1. - P141-147. - ISSN 1063-7834, DOI 10.1134/S1063783407010234
Примечания : Cited References: 8
Предметные рубрики: TRANSITIONS
Аннотация: Thermophysical and structural studies of an (NH4)(2)KMoO3F3 crystal show that this crystal belongs to the family of elpasolites (space group Fm (3) over barm) and undergoes an order-disorder phase transition at To 241.5 K. Under hydrostatic pressure, this phase transition splits into two consecutive transitions at the tricritical point with parameters T-tr = 232.5 K and p(tr)= 0.21 GPa. It was found that anomalous hysteresis and relaxation phenomena accompany the transitions from the cubic to both distorted phases. The results are analyzed taking into account the data on the phase transition in the related elpasolite (NH4)(2)KWO3F3.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

20.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Zvezdin A. K., Krotov S. S., Kadomtseva A. M., Vorob'ev G. P., Popov Y. F., Pyatakov A. P., Bezmaternykh L. N., Popova E. A.
Заглавие : Magnetoelectric effects in gadolinium iron borate GdFe3(BO3)(4)
Разночтения заглавия :авие SCOPUS: Magnetoelectric effects in gadolinium iron borate GdFe3(BO 3)4
Место публикации : JETP Letters. - 2005. - Vol. 81, Is. 6. - P.272-276. - ISSN 0021-3640, DOI 10.1134/1.1931014
Примечания : Cited References: 23
Предметные рубрики: OPTICAL SPECTROSCOPY
TRANSITIONS
POLARIZATION
PHASE
Аннотация: Magnetoelectric interactions have been investigated in a single crystal of gadolinium iron borate GdFe3(BO3)(4), whose macroscopic symmetry is characterized by the crystal class 32. Using the results of this study, the interplay of magnetic and electric orderings occurring in the system has been experimentally revealed and theoretically substantiated. The electric polarization and magnetostriction of this material that arise in spin-reorientation transitions induced by a magnetic field have been investigated experimentally. For H parallel to c and H perpendicular to c, H-T phase diagrams have been constructed, and a strict correlation between the changes in the magnetoelectric and magnetoelastic properties in the observed phase transitions has been ascertained. A mechanism of specific noncollinear antiferroelectric ordering at the structural phase transition point was proposed to interpret the magnetoelectric behavior of the system within the framework of the symmetry approach in the entire temperature range. This ordering provides the conservation of the crystal class of the system when the temperature decreases to the antiferroelectric ordering point. The expressions that have been obtained for the magnetoelectric and magnetoelastic energy describe reasonably well the behavior of gadolinium iron borate observed experimentally. (C) 2005 Pleiades Publishing, Inc.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие