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=TRANSFORMATIONS<.>)

Общее количество найденных документов : 7
Показаны документы с 1 по 7

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Molokeev M. S., Misyul' S. V.
Заглавие : Structural changes during phase transitions and the critical and noncritical order parameters in the (NH4)3Nb(O2)2F4 crystal
Место публикации : Phys. Solid State: MAIK Nauka-Interperiodica / Springer, 2012. - Vol. 54, Is. 1. - P.143-154. - ISSN 1063-7834, DOI 10.1134/S1063783412010234. - ISSN 1090-6460
Примечания : Cited References: 17. - This study was supported by the Russian Foundation for Basic Research (project no. 09-02-00062) and 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: TRANSFORMATIONS
OXYFLUORIDE
CELL
Аннотация: The structures of two phases of the (NH4)3Nb(O2)2F4 crystal, namely, the parent cubic phase and the most distorted low-temperature phase, have been determined from data of an X-ray diffraction experiment performed 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 displacements and allows the interpretation of the obtained experimental data. It has been found that the most probable sequence of structural transformations occurring in the crystal can be schematically represented in the following form: Fm3¯m−→−−−−(η1,η1,η)Γ+5(11−7)C2/m−→−−−−−−−−−−−−−−−−(η1,η1,η)(0,0,0,0,0,ξ,0−ξ,0,0,0,0)Γ+5(11−7)⊗Σ2(4−2)P21/m−→−−−−−−−−−−−−−−−−−−−−−−−−−−−−(η1,η1,η)(0,0,0,0,0,ξ,0−ξ,0,0,0,0)(0,0,0,0,0,ε,0,ε,0,0,0,0)Γ+5(11−7)⊗Σ2(4−2)⊗Σ3(4−3)P21/n.\begin{gathered} Fm\bar 3m\xrightarrow[{(\eta 1,\eta 1,\eta )}]{{\Gamma _5. + (11 - 7)}}C2/m\xrightarrow[{(\eta 1,\eta 1,\eta )(0,0,0,0,0,\xi ,0 - \xi ,0,0,0,0)}]{{\Gamma _5. + (11 - 7) \otimes \Sigma _2 (4 - 2)}}P2_1 /m \hfill \\ \xrightarrow[{(\eta 1,\eta 1,\eta )(0,0,0,0,0,\xi ,0 - \xi ,0,0,0,0)(0,0,0,0,0,\varepsilon ,0,\varepsilon ,0,0,0,0)}]{{\Gamma _5. + (11 - 7) \otimes \Sigma _2 (4 - 2) \otimes \Sigma _3 (4 - 3)}}P2_1 /n. \hfill \\ \end{gathered}
Смотреть статью,
WoS,
Читать в сети ИФ
Найти похожие

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

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Molokeev M. S., Misyul' S. V.
Заглавие : Processes of ordering of structural elements, critical and noncritical parameters of phase transitions in the (NH4)3WO3F3 crystal
Место публикации : Phys. Solid State: MAIK Nauka-Interperiodica / Springer, 2012. - Vol. 54, Is. 1. - P.155-165. - ISSN 1063-7834, DOI 10.1134/S1063783412010222. - ISSN 1090-6460
Примечания : Cited References: 18. - This study was supported by the Russian Foundation for Basic Research (project no. 09-02-00062) and 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: OXYFLUORIDE
TRANSFORMATIONS
(NH4)3TiOF5
DISORDER
Аннотация: The structure of the low-temperature triclinic phase of the (NH4)3WO3F3 crystal has been determined and the structure of the cubic phase of this crystal has been refined from data of an X-ray diffraction experiment performed 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 obtained experimental data. It has been found that the symmetry transformation in the crystal can be schematically represented in the following form: Fm3¯m(Z=4)→P1¯(Z=1)→P1¯(Z=6)Fm\bar 3m(Z = 4) \to P\bar 1(Z = 1) \to P\bar 1(Z = 6) . This transformation is accompanied by the complete ordering of WO3F3 polyhedra and the displacement of NH4 ions.
Смотреть статью,
Scopus,
WoS,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Mikhlin Y. L., Vishnyakova E. A., Romanchenko A. S., Saikova S. V., Likhatski M. N., Larichev Y. V., Tuzikov F. V., Zaikovskii V. I., Zharkov S. M.
Заглавие : Oxidation of Ag nanoparticles in aqueous media: Effect of particle size and capping
Место публикации : Appl. Surf. Sci.: Elsevier Science, 2014. - Vol. 297. - P.75-83. - ISSN 0169-4332, DOI 10.1016/j.apsusc.2014.01.081. - ISSN 1873-5584
Примечания : Cited References: 58. - This work was partially financially supported by the Ministry of Education and Science of RF (Grant 8580) and RFBR (12-03-31178).
Предметные рубрики: EX-SITU XPS
POLYCRYSTALLINE SILVER ELECTRODES
RAY PHOTOELECTRON-SPECTROSCOPY
METAL NANOPARTICLES
ELECTROCHEMICAL OXIDATION
ABSORPTION SPECTROSCOPY
PYROLYTIC-GRAPHITE
OXYGEN-ADSORPTION
TRANSFORMATIONS
DISSOLUTION
Ключевые слова (''Своб.индексиров.''): silver nanoparticles--oxidation--resistive switching effect--x-ray photoelectron spectroscopy
Аннотация: Many applications and environmental impact of silver-bearing nanomaterials critically depend upon their specific reactivity, which is still poorly understood. Here, silver nanoparticles (Ag NPs) of about 3-5 nm and 10-12 nm in diameter, uncapped and capped with l-glucose or citrate, were prepared, characterized using UV-vis absorption spectroscopy, SAXS, TEM, and their (electro) chemical oxidation was examined in comparison with each other and bulk metal applying scanning tunneling microscopy and spectroscopy, cyclic voltammetry, and XPS. A resistive switching effect was found in the tunneling spectra measured in air at the smaller uncapped Ag NPs deposited on HOPG and was interpreted in terms of Ag transfer between the particle and the probe. The anodic oxidation of these Ag NPs in 1 M NaOH yielded 3D Ag2O, while only a layer of "primary"Ag(I) oxide emerged on larger uncapped nanoparticles during the potential sweep. The formation of AgO at higher potentials proceeded readily at the "primary"oxide but was retarded at the smaller NPs. The citrate- and glucose-capping substantially impeded the formation both of Ag2O and AgO. The findings highlighted, particularly, a non-trivial effect of particle size and transient mobilization of Ag species on the reactions of silver nanoparticles. (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) : Krylov A. S., Vtyurin A. N., Voronov V. N., Krylova S. N.
Заглавие : Manifestations of Structural Phase Transitions in a Rb2KLuF6 Crystal in Its Raman Spectra
Коллективы : Russian Foundation for Basic Research [16-02-00102, 18-02-00754]
Место публикации : Opt. Spectrosc. - 2019. - Vol. 126, Is. 4. - P.341-345. - ISSN 0030-400X, DOI 10.1134/S0030400X1904012X. - ISSN 1562-6911(eISSN)
Примечания : Cited References: 27. - This work was supported by the Russian Foundation for Basic Research, project nos. 16-02-00102, 18-02-00754.
Предметные рубрики: SCATTERING
ELPASOLITES
LUMINESCENCE
TRANSFORMATIONS
FLUORIDES
Аннотация: The Raman spectra of an Rb2KLuF6 crystal are studied in the temperature range from 8 to 375 K, which includes two phase transitions: one of which proceeds from a cubic to a tetragonal phase, while the other transition takes place from a tetragonal to a monoclinic phase. An analysis of the temperature dependences of parameters of spectral lines shows that the former transition is of the second kind, while the latter transition is of the first kind, close to the tricritical point. It is shown that the structural phase transitions in the Rb2KLuF6 double perovskite are not associated with disordering. The former transition is associated with rotations of LuF6 octahedra around the fourth-order axis, while the latter transition is related with rotations of octahedra and displacements of rubidium ions.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Myagkov V. G., Zhigalov V. S., Matsynin A. A., Bykova L. E., Mikhlin Y. L., Bondarenko G. N., Patrin G. S., Yurkin G. Yu.
Заглавие : Formation of ferromagnetic germanides by solid-state reactions in 20Ge/80Mn films
Место публикации : Thin Solid Films: Elsevier Science, 2014. - Vol. 552. - P.86-91. - ISSN 0040-6090, DOI 10.1016/j.tsf.2013.12.029
Примечания : Cited References: 53
Предметные рубрики: PHASE-FORMATION
MAGNETIC-PROPERTIES
Mn5Ge3 FILMS
X-RAY
Ge(111)
TRANSFORMATIONS
DIFFUSION
SPECTRA
SYSTEM
LAYERS
Ключевые слова (''Своб.индексиров.''): manganite-germanium--solid state reaction--first phase--mn5ge3 alloy--carbon impurity--oxygen impurity--annealing--magnetic anisotropy
Аннотация: Solid state reactions between Ge and Mn films are systematically examined using X-ray diffraction, photoelectron spectroscopy, and magnetic and electrical measurements. The films have a nominal atomic ratio Ge:Mn = 20:80 and are investigated at temperatures from 50 to 500 °C. It is established that after annealing at ~ 120°C, the ferromagnetic Mn5Ge3 phase is the first phase to form at the 20Ge/80Mn interface. As the annealing temperature increases to 300°C, the weak magnetic Mn5Ge 2 + Mn3Ge phases simultaneously begin to grow and they become dominant at 400°C. Increasing the annealing temperature to 500°C leads to the formation of the ferromagnetic phase with a Curie temperature TC ~ 350-360 K and magnetization 14-25 kA/m at room temperature. The X-ray diffraction study of the samples shows the reflections from the Mn 5Ge3 phase, and the photoelectron spectra contain the oxygen and carbon peaks. The homogeneous distribution of oxygen and carbon over the sample thickness suggests that the increased Curie temperature and magnetization are related to the migration of C and O atoms into the Mn 5Ge3 lattice and the formation of the Nowotny phase Mn5Ge3CxOy. The initiation temperature (~ 120 C) is the same in the Mn5Ge3 phase with the solid-state reactions in the Ge/Mn films as well as in the phase separation in the GexMn1 - x diluted semiconductors. Thus, we conclude that the synthesis of the Mn5Ge3 phase is the moving force for the spinodal decomposition of the GexMn 1 - x diluted semiconductors.
Смотреть статью,
Scopus,
WoS,
WOS,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Grishina, Svetlana, Kodera, Peter, Goryainov, Sergey, Oreshonkov A. S., Seryotkin, Yurii, Simko, Frantisek, Polozov, Alexander G.
Заглавие : Application of Raman spectroscopy for identification of rinneite (K3NaFeCl6) in inclusions in minerals
Коллективы : Russian Foundation for Basic ResearchRussian Foundation for Basic Research (RFBR) [18-05-00682]; European Regional Development FundEuropean Union (EU) [ITMS 26240220086]; Vedecka Grantova Agentura MSVVaS SR a SAV [1/0313/20]
Место публикации : J. Raman Spectrosc. - 2020. - Vol. 51, Is. 12. - P.2505-2516. - ISSN 0377-0486, DOI 10.1002/jrs.6005. - ISSN 1097-4555(eISSN)
Примечания : Cited References: 55. - Russian Foundation for Basic Research, Grant/Award Numbers: 18-05-00682, 18-05-00682; European Regional Development Fund, Grant/Award Number: ITMS 26240220086; Vedecka Grantova Agentura MSVVaS SR a SAV, Grant/Award Number: 1/0313/20
Предметные рубрики: SALT MELT
IRON
DEPOSIT
FLUIDS
TRANSFORMATIONS
FERRIHYDRITE
Аннотация: Solid daughter phases in fluid and salt melt inclusions in minerals provide important clues to characterization of mineral‐forming processes. The analysis of the fluid inclusions often requires the exposure of the daughter minerals. Rinneite (K3NaFeCl6), which is a hygroscopic mineral, decomposes in air and cannot thus be identified by conventional methods. A combined approach has been applied for investigation of synthetic and natural rinneite to acquire its diagnostic Raman spectrum for a nondestructive identification. We used natural rinneite inclusions in halite, suitable for applying a complex of methods, to clear up the reference spectrum. Improved high‐resolution X‐ray diffraction (XRD) data obtained from natural rinneite inclusion are comparable with that of previously published, with similar unit cell dimensions. Polarized Raman spectra of natural inclusions were obtained using different geometries and polarization of the incident and scattered light. Interpretation of experimental Raman spectra was performed within the framework of lattice dynamics simulations and group analysis. Individual spectral bands are interpreted in terms of Raman‐active vibrational modes of K3NaFeCl6 structural units. Raman spectrum of synthetic rinneite with main peaks at 75, 91, 103, 143, 167, 171, 187, and 239 cm−1 agrees well with the spectra of rinneite inclusions in halite from the Nepa potash deposit and rinneite daughter minerals in salt melt inclusions hosted by quartz veinlets from the porphyry gold systems in the Central Slovakia Volcanic Field. This provides a firm basis for any future identification of this mineral worldwide, using nondestructive Raman spectroscopy.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие