Главная
Авторизация
Фамилия
Пароль
 

Базы данных


Труды сотрудников ИФ СО РАН - результаты поиска

Вид поиска

Область поиска
Формат представления найденных документов:
полный информационныйкраткий
Отсортировать найденные документы по:
авторузаглавиюгоду изданиятипу документа
Поисковый запрос: (<.>S=(NH4)(3)WO3F3<.>)
Общее количество найденных документов : 9
Показаны документы с 1 по 9
1.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Ivliev M. P., Misyul S. V., Molokeev M. S., Sakhnenko V. P.
Заглавие : Pseudo-proper ferroelectric phase transitions in oxyfluoride K3WO3F3
Место публикации : Phase Transit.: Taylor & Francis, 2014. - Vol. 87, Is. 6. - P.592-602. - ISSN 0141-1594, DOI 10.1080/01411594.2013.878026. - ISSN 1029-0338
Примечания : Cited References: 14. - This study was supported by the of the President of the Russian Federation for the Support of Leading Scientific Schools [Grant NSh-924.2014.2].
Предметные рубрики: TRANSFORMATIONS
(NH4)(3)MOO3F3
(NH4)(3)WO3F3
CS
Ключевые слова (''Своб.индексиров.''): phase transition--statistical mechanics--order-disorder--ferroelectric--transformations--(nh4)(3)moo3f3--(nh4)(3)wo3f3--cs
Аннотация: Based on the structural data on the phases of cryolite (ordered perovskite) K3WO3F3, we develop a statistical model, which allows to describe the sequence of phase transitions observed in this compound using a unified approach. According to the model, the crystal possesses two structural subsystems: the K cations located in the octahedral positions and the WO3F3 octahedra in positions alternating with K cations. In the symmetric (cubic) phase, each subsystem can be found in one of the eight states. At decreasing temperature, an orientational phase transition in the subsystem of octahedra occurs first, followed by a phase transition to the low-temperature phase, caused by the loss of stability with respect to the ordering in the K cation subsystem. We find that the electric polarization occurs as pseudoproper and discuss the mechanisms of formation of the phase states.
Смотреть статью,
Scopus,
WoS,
Читать в сети ИФ
Найти похожие
2.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Molokeev M. S., Misyul' S. V.
Заглавие : Structural transformations and the critical and noncritical parameters during the phase transition in the (NH4)(2)KWO3F3 oxyfluoride
Разночтения заглавия :авие SCOPUS: Structural transformations and the critical and noncritical parameters during the phase transition in the (NH4)2KWO3F3 oxyfluoride
Место публикации : Phys. Solid State: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2011. - Vol. 53, Is. 8. - P1672-1679. - ISSN 1063-7834, DOI 10.1134/S1063783411080208
Примечания : Cited References: 18. - This study was supported by the Council on Grants from the President of the Russian Federation for Support of Leading Scientific Schools of the Russian Federation (grant no. NSh-4645.2010.2).
Предметные рубрики: MOLECULAR CRYSTALS
DISORDER
(NH4)(3)WO3F3
Аннотация: The structures of two phases of the (NH4)(2)KWO3F3 crystal have been determined from X-ray diffraction data obtained for a powder sample. The profile and structural parameters have been refined according to the procedure implemented in the DDM program. The results obtained have been discussed with invoking the group-theoretical analysis of the complete order parameter condensate, which takes into account the critical and noncritical atomic orderings and allows one to interpret the experimental data. It has been found that the symmetry transformation in the crystal can be schematically represented in the form Fm (3) over barm (10-10((X) over bar5)) - ((eta, 0, 0, 0, 0, 0)) Pmmn.This transformation is accompanied by the ordering of WO3F3 polyhedra and the displacement of NH4 and K ions.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
3.

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
4.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Vtyurin A. N., Gerasimova Y. V., Shestakov N. P., Ivanenko A. A.
Заглавие : Influence of the Substitution of the Central Me Atom in Ammonium Oxyfluorides on Phase Transitions: IR Spectroscopy Study
Разночтения заглавия :авие SCOPUS: Influence of the substitution of the central Me atom in ammonium oxyfluorides on phase transitions: IR spectroscopy study
Место публикации : Phys. Solid State: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2011. - Vol. 53, Is. 4. - P840-844. - ISSN 1063-7834, DOI 10.1134/S1063783411040330
Примечания : Cited References: 7. - This study was supported by the Russian Foundation for Basic Research (project no. 08-02-00066-a).
Предметные рубрики: (NH4)(3)WO3F3
Аннотация: Comparative investigations of infrared absorption spectra of ion-molecular crystals of the ammonium-containing oxyfluorides (NH(4))(3)WO(3)F(3) and (NH(4))(3)MoO(3)F(3) have been performed. It has been found that the parameters of the vibrational spectra exhibit anomalies in the ranges of internal vibrations of the MeO(3)F(3) octahedral groups and ammonium ions near the phase transition temperatures. A comparative analysis of the IR spectra allows us to affirm that the studied phase transition in (NH(4))(3)WO(3)F(3) is primarily associated with the ordering of octahedral groups, whereas in (NH(4))(3)MoO(3)F(3), it is mainly due to the ordering of ammonium groups and the distortion of ammonium ions by the crystal environment.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
5.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Flerov I. N., Fokina V. D., Gorev M. V., Bogdanov E. V., Molokeev M. S., Bovina A. F., Kocharova A. G.
Заглавие : Effect of deuteration on the thermal properties and structural parameters of the (NH4)(2)WO2F4 oxyfluoride
Разночтения заглавия :авие SCOPUS: Effect of deuteration on the thermal properties and structural parameters of the (NH4)2WO2F4 oxyfluoride
Место публикации : Phys. Solid State: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2007. - Vol. 49, Is. 6. - P1149-1156. - ISSN 1063-7834, DOI 10.1134/S1063783407060212
Примечания : Cited References: 11
Предметные рубрики: PEROVSKITE-LIKE OXYFLUORIDES
PHASE-TRANSITIONS
(NH4)(3)WO3F3
(NH4)(3)TIOF5
Аннотация: The thermal properties and structure of (ND4)(2)WO2F4 crystals are investigated. It is established that deuteration does not lead to a change in the symmetry of the initial phase Cmcm but considerably decreases the extent of its disordering, which, in turn, brings about a substantial decrease in the phase transition entropy. Apart from the anomalies associated with phase transitions characteristic of the protonic compound, the heat capacity exhibits two additional anomalies. Analysis of the phase diagram of the deuterated crystal reveals a triple point at a pressure p = 0.18 GPa, which is predicted for (NH4)(2)WO2F4 at about 0.7 GPa.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
6.

Вид документа : Статья из сборника (однотомник)
Шифр издания :
Автор(ы) : Vtyurin A. N., Krylov A. S., Gerasimova J. V., Fokina V. D., Kocharova A. G., Laptash N. M., Voyt E. I., Surovtsev N. V.
Заглавие : Raman scattering study of ordering processes and phase transitions in A(2)BWO(3)F(3) oxyfluorides crystals
Разночтения заглавия :авие SCOPUS: Raman scattering study of ordering processes and phase transitions in A2BWO3F3oxyfluorides crystals
Место публикации : 12TH INTERNATIONAL CONFERENCE ON PHONON SCATTERING IN CONDENSED MATTER (PHONONS 2007). Ser. Journal of Physics Conference Series: IOP PUBLISHING LTD, 2007. - Vol. 92: 12th International Conference on Phonon Scattering in Condensed Matter (PHONONS 2004) (JUL 15-20, 2007, Paris, FRANCE). - Ст.12158. - ISBN 1742-6588, DOI 10.1088/1742-6596/92/1/012158
Примечания : Cited References: 6
Предметные рубрики: (NH4)(3)WO3F3
Аннотация: Raman spectra of perovskite-like (NH(4))(3)WO(3)F(3), (NH(4))(2)KWO(3)F(3) and Cs(2)(NH(4))WO(3)F(3) oxyfluorides are obtained in a wide temperature range including transition points. Transition anomalies are found and analyzed. Transformation in (NH(4))(3)WO(3)F(3) is shown to be bound with octahedron groups ordering and strong distortion of ammonium ions due to H-bond formation, that is accompanied by cell volume multiplication, hardening and formation of complex discrete low frequency lattice spectrum. Same cell doubling was found in (NH(4))(2)KWO(3)F(3), but without lattice ordering Cs(2)(NH(4))WO(3)F(3) lattice stays disordered down to 15 K.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
7.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Flerov I. N., Gorev M. V., Fokina V. D., Molokeev M. S., Vasil'ev A. D., Bovina A. F., Laptash N. M.
Заглавие : Heat capacity, structural disorder, and the phase transition in cryolite (NH4)(3)Ti(O-2)F-5
Разночтения заглавия :авие SCOPUS: Heat capacity, structural disorder, and the phase transition in cryolite (NH4)3Ti(O2)F5
Место публикации : Phys. Solid State: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2006. - Vol. 48, Is. 8. - P1559-1567. - ISSN 1063-7834, DOI 10.1134/S1063783406080221
Примечания : Cited References: 18
Предметные рубрики: PEROVSKITE-LIKE OXYFLUORIDES
CRYSTAL-STRUCTURES
(NH4)(3)TIOF5
(NH4)(3)WO3F3
DIFFRACTION
Аннотация: The heat capacity, T-p phase diagrams, and unit cell parameters of cryolite (NH4)(3)Ti(O-2)F-5 were studied over a wide temperature range. A phase transition was found near 226 K, and its thermodynamic characteristics and their dependence on the crystallization conditions were determined. The coordinates and thermal parameters of atoms in the Fm3m phase were refined. An analysis of the electron density distribution and the transition entropy showed that the mechanism of the structural transition involves, above all, rotation of the Ti(O-2)F-5 octahedra. Possible models of disordering of tetrahedral ammonium groups are considered.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
8.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Smirnov L. S., Kolesnikov A. I., Flerov I. N., Laptash N. M.
Заглавие : Inelastic neutron scattering study of the specific features of the phase transitions in (NH4)(2)WO2F4
Коллективы : Russian Foundation [09-02-00062]; U.S. Department of Energy [DE-AC05-00OR22725, DE-AC02-06CH11357]
Место публикации : Phys. Solid State. - 2009. - Vol. 51, Is. 11. - P.2362-2366. - ISSN 1063-7834, DOI 10.1134/S1063783409110262
Примечания : Cited References: 15. - This study was supported by the Russian Foundation for Basic Research (project no. 09-02-00062) and the ORNL/SNS controlled by UT-Battelle, LLC, the U.S. Department of Energy (contract DE-AC05-00OR22725); the experiments in the Argonne National Laboratory were supported by the Office of General Sciences on Energy, Division of Materials Science of the U.S. Department of Energy (contract DE-AC02-06CH11357).
Предметные рубрики: OXYFLUORIDE
(NH4)(3)WO3F3
MECHANISM
RB
CS
Аннотация: Oxyfluoride (NH4)(2)WO2F4 has been studied by the inelastic neutron scattering method over a wide temperature range 10-300 K at two initial neutron energies of 15 and 60 meV. The role of tetrahedral ammonium groups in the mechanism of sequential phase transitions at T (1) = 201 K and T (2) = 160 K has been discussed.
WOS,
Читать в сети ИФ
Найти похожие
9.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Fokina V. D., Gorev M. V., Kocharova A. G., Flerov I. N., Pogoreltsev E.I.
Заглавие : Phase transitions and thermodynamic properties of (NH4)(3)VO2F4 cryolite
Место публикации : Solid State Sci. - 2009. - Vol. 11, Is. 4. - P.836-840. - ISSN 1293-2558, DOI 10.1016/j.solidstatesciences.2008.11.004
Примечания : Cited Reference Count: 17. - Гранты: The authors are grateful to Dr. SM. Mel'nikova for the permission to use the unpublished results.; This work was supported by the Russian Foundation for Basic Research (project 06-02-16102).Финансирующая организация: Russian Foundation for Basic Research [06-02-16102]
Предметные рубрики: PEROVSKITE-LIKE OXYFLUORIDES
(NH4)(3)TIOF5
CS
(NH4)(3)WO3F3
DIFFRACTION
(NH4)3VO2F4
ELPASOLITE
METALS
RB
Ключевые слова (''Своб.индексиров.''): oxyfluorides--phase transition--calorimetry--phase diagram--ferroelectricity--calorimetry--ferroelectricity--oxyfluorides--phase diagram--phase transition--calorimetry--ferroelectricity--halide minerals--phase diagrams--sugar (sucrose)--thermodynamic properties--calorimetric measurements--cubic phase--first-order phase transitions--heat capacities--oxyfluorides--phase transition temperatures--pressure dependences--structural transformations--temperature ranges--phase transitions
Аннотация: Calorimetric measurements performed in a wide temperature range on (NH4)(3)VO2F4 have shown the presence of four heat capacity anomalies at T-1 = 438 K, T-2 = 244 K, T-3 = 210.2 K, T-4 = 205.1 K associated with the first order phase transitions. In accordance with the permittivity behavior, the structural transformations are of nonferroelectric nature. Pressure dependence of the phase transition temperatures has been studied by DTA under pressure. The entropy of phase transitions is analyzed mainly in the framework of the orientational disordering of NH4+ and VO2F43- ions in a cubic phase. (C) 2008 Elsevier Masson SAS. All rights reserved.
WOS,
Scopus,
eLibrary
Найти похожие
 

Другие библиотеки

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