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1.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Isaenko L., Dong L., Melnikova S. V., Molokeev M. S., Korzhneva K. E., Krinitsin P. G., Kurus A. F., Samoshkin D. A., Belousov R. A., Lin Zh.
Заглавие : Phase transitions and nonlinear optical property modifications in BaGa4Se7
Колич.характеристики :8 с
Место публикации : Inorg. Chem. - 2024. - Vol. 63, Is. 21. - P.10042-10049. - ISSN 00201669 (ISSN), DOI 10.1021/acs.inorgchem.4c01341. - ISSN 1520510X (eISSN)
Примечания : Cited References: 27. - This work was supported by the National Natural Science Foundation of China, grant no. 22133004 (first-principles studies), the Ministry of Education and Science of the Russian Federation, grant FSUS-2020-0036 (crystal growth, crystal structure analysis, and band gap measurement), and partly done on the state assignment of IGM SB RAS no. 122041400031-2 (composition chemical analysis and SHG coefficient measurements)
Аннотация: Phase transitions can change the crystal structure and modify the physical properties of crystals. In this work, we investigate the phase transition behavior in BaGa4Se7, an important middle infrared (mid-IR) nonlinear optical (NLO) crystal, in the temperature range from room temperature to 1173 K. Interestingly, the BaGa4Se7 crystal undergoes a reversible ferroelastic phase transition at T = 528 K, resulting in the presence of a newly discovered phase (γ-phase) at the higher temperature. The experimental temperature dependence of optical birefringence, as well as the first-principles birefringence and NLO coefficients, reveals that the γ-phase exhibits larger birefringence and better NLO properties compared with those of the low-temperature phase (α-phase). This work demonstrates that phase-transition-induced structural modification can improve the mid-IR NLO properties, which would provide an effective avenue to obtain materials with good optoelectronic performance.
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2.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Gudim I. A., Mikhashenok N. V., Vasiliev A. D., Melnikova S. V., Pavlovskii M. S., Skorobogatov S. A., Pankrats A. I.
Заглавие : Features of the melt–solution synthesis of the TbCr3(BO3)4 single crystals
Колич.характеристики :6 с
Место публикации : J. Cryst. Growth. - 2024. - Vol. 637-638. - Ст.127716. - ISSN 00220248 (ISSN), DOI 10.1016/j.jcrysgro.2024.127716. - ISSN 18735002 (eISSN)
Примечания : Cited References: 22. - The authors thank A.V. Zamkov for assistance in preparing the samples for the conoscopic study. The characterization and examination of the samples were performed at the Center for Collective Use, Krasnoyarsk Scientific Center, Siberian Branch of the Russian Academy of SciencesThis study was supported in part by the Russian Science Foundation and the Krasnoyarsk Territorial Foundation for Support of Scientific and R&D Activity, project no. 22-12-20019
Аннотация: The phase formation of terbium chromoborate TbCr3(BO3)4 in the bismuth trimolybdate and lithium tungstate melt–solutions has been studied. The absence of the terbium chromoborate trigonal phase in the bismuth trimolybdate-based system at all component ratios has been shown. The component ratio in the lithium tungstate-based system has been found at which the TbCr3(BO3)4 trigonal crystals are formed at temperatures above 1100 °C; below this temperature, the monoclinic phase dominates. The structural and magnetic properties of the grown crystals have been studied. It has been established that the trigonal and monoclinic TbCr3(BO3)4 crystals synthesized from the lithium tungstate-based solvent exhibit identical magnetic properties. At the same time, a significant difference of the magnetic properties of the single crystals synthesized from the bismuth molybdate melt–solution has been observed. This difference has been attributed to the effect of Bi3+ ions that partially replace Tb3+ ions.
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3.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Kurus, Alexey, Yelisseyev, Alexander, Lobanov, Sergei, Plyusnin, Pavel, Molokeev M. S., Solovyev, Leonid, Samoshkin, Dmitry, Stankus, Sergei, Melnikova S. V., Isaenko, Lyudmila
Заглавие : Thermophysical properties of lithium thiogallate that are important for optical applications
Коллективы : Russian Science Foundation, RussiaRussian Science Foundation (RSF) [19-12-00085]; RFBRRussian Foundation for Basic Research (RFBR) [20-42-543006\20]; Novosibirsk region [20-42-543006\20]
Место публикации : RSC Adv. - 2021. - Vol. 11, Is. 62. - P.39177-39187. - ISSN 2046-2069(eISSN), DOI 10.1039/d1ra05698k
Примечания : Cited References: 41. - Crystal growth and investigation of physical properties were supported by Russian Science Foundation, Russia (#19-12-00085). Spectroscopic study was performed on a state assignment of the Institute of Geology and Mineralogy, Siberian Branch of Russian Academy of Sciences Russia and Ministry of Science and Higher Education, Russia. Measurements of thermal conductivity were funded by RFBR and Novosibirsk region (grant #20-42-543006\20)
Предметные рубрики: NON-ENANTIOMORPHOUS CRYSTAL
MID-IR
SINGLE-CRYSTALS
FLASH METHOD
Аннотация: Lithium thiogallate LiGaS2 is one of the most common nonlinear crystals for mid-IR due to its extreme beam strength and wide transparency range; however, its thermophysical properties have not yet been practically studied. Large crystals of high optical quality are grown. DTA revealed features at 1224 K below melting point (1304 K) that are associated with the oxygen containing compounds of the LiGaO2−xSx type. The thermal conductivity of LiGaS2 (about 10.05 W (m−1 K−1)) and band gap value (3.93 eV at 300 K) are found to be the highest in the LiBC2 family. Isotropic points in the dispersion characteristics for the refractive index are found and LiGaS2-based narrow-band optical filters, smoothly tunable with temperature changes, are demonstrated. Intense blue photoluminescence of anionic vacancies VS is observed at room temperature after annealing LiGaS2 in vacuum, whereas orange low-temperature emission is related to self-trapped excitons. When LiGaS2 crystals are heated, spontaneous luminescence (pyroluminescence) takes place, or thermoluminescence after preliminary UV excitation; the parameters of traps of charge carriers are estimated. The obtained data confirm the high optical stability of this material and open up prospects for the creation of new optical devices based on LiGaS2.
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4.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Pogoreltsev E. I., Bogdanov E. V., Melnikova S.V., Flerov I. N., Laptash N. M.
Заглавие : (NH4)3HfF7: Crystallooptical and calorimetric studies of a number of successive phase transitions
Место публикации : J. Fluor. Chem.: Elsevier, 2017. - Vol. 204. - P.45-49. - ISSN 00221139 (ISSN), DOI 10.1016/j.jfluchem.2017.10.004
Примечания : Cited References: 14
Аннотация: Single crystals of (NH4)3HfF7 were grown. Polarising optical observations as well as measurement of the heat capacity and birefringence Δn(Т) were performed in the temperature range of 200–310 K. Reversible phase transitions at temperatures T0 = 290 K, Т1 = 280.5 K, Т2 ≈ 273 K, Т3 = 266 K, Т4 = 259 K, Т5 = 231 K, Т6 = 229 K were found. Observations in polarised light make it possible to suggest a sequence of changes in the symmetry groups for these transitions: Fm3m ⟵Т0→ cub. ⟵Т1→ mmm (1) ⟵Т2→ mmm (2) ⟵Т3→ mmm (3) ⟵Т5→ 2/c. The T-p phase diagram was studied and the temperature boundaries of the stability of the distorted crystalline phases were determined. A significant change of the entropy at successive phase transitions ΣΔS = 10.6 J/mol K indicates a disordering of the initial cubic phase.
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5.

Вид документа : Статья из сборника (однотомник)
Шифр издания :
Автор(ы) : Chekanova L. A., Denisova E. A., Melnikova S. V., Iskhakov R. S., Komogortsev S. V., Velikanov D. A., Nemtsev I. V.
Заглавие : Magnetic properties of Co/Cu multilayered wires electroless deposited in different porous template
Коллективы : Moscow International Symposium on Magnetism, Московский государственный университет им. М.В. Ломоносова
Место публикации : Moscow Int. Symp. on Magnet. (MISM-2014): Book of abstracts. - 2014. - P.154. - ISBN 978-5-91978-025-0
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6.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Melnikova S. V., Laptash N. M.
Заглавие : Influence of atmospheric humidity on the symmetry and phase transitions of layered potassium oxyfluorides K2NbOF5 center dot H2O
Место публикации : Phys. Solid State: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2013. - Vol. 55, Is. 6. - P.1231-1235. - ISSN 1063-7834, DOI 10.1134/S1063783413060243
Примечания : Cited References: 8. - This study was supported by the Council on Grants from the President of the Russian Federation (grant no. NSh-4828.2012.2).
Предметные рубрики: OXOPEROXOFLUORO COMPLEXES
MO V
CRYSTAL STRUCTURE
OXOFLUORO
MONOHYDRATE
Аннотация: Crystals of K2NbOF5 center dot H2O have been grown, polarization optical investigations have been performed, and the birefringence and rotation angle of the optical indicatrix have been measured in the temperature range 100-400 K. It has been found that, depending on the degree of atmospheric humidity, the layered K2NbOF5 center dot H2O crystal at room temperature can be in three states, namely, A, B, and C, which differ in symmetry and properties of the crystal. The K2NbOF5 center dot H2O crystal in the A state exists at a relative humidity RH = 90-100% and undergoes a first-order improper ferroelastic phase transition P a dagger" C2/m, which is accompanied by strong anomalies of the optical characteristics, twinning, and shear strain x (6) at temperatures T (2) (a dagger") = 308 K and T (2) (a dagger) = 313 K. The most stable state of the K2NbOF5 sdH(2)O crystal is the B state (RH = 20-90%), which retains the monoclinic symmetry C2/m in the temperature range 100-370 K. In a dry atmosphere (RH = 0-20%) or at T (1) a parts per thousand 370 K, the crystal becomes anhydrous (K2NbOF5) with the symmetry P4/nmm (the C state). The difference between the crystals in the states A and B is explained by the presence or absence of water molecules in interlayer spaces.
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7.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Melnikova S. V., Isaenko L. I.
Заглавие : Linear optical properties of γ-modification of bismuth borate BiB3O6
Место публикации : Phys. Solid State: MAIK Nauka-Interperiodica / Springer, 2012. - Vol. 54, Is. 10. - P.1966-1969. - ISSN 1063-7834, DOI 10.1134/S1063783412100228
Примечания : Cited References: 9. - 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-4828.2012.2) and the Siberian Branch of the Russian Academy of Science (integration project no. 28).
Предметные рубрики: GROWTH
Аннотация: The refractive index dispersion of the γ-BiB3O6 crystal in the wavelength range 0.43–0.81 μm has been measured. It has been shown that the principal refractive indices n 1, n 2, and n 3 are on average higher than those of α-BiB3O6, but are slightly lower than those of δ-BiB3O6. The temperature dependences of the rotation angle φ(T) of the optical indicatrix and birefringence Δn 2(T) = (n 1 − n 3)(T) have been studied in the temperature range 100–963 K. It has been shown that the γ-BiB3O6 crystal is stable in this temperature region.
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8.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Melnikova S. V., Vasilev A. D., Kocharova A. G.
Заглавие : The role of structural and nonstructural water in oxyfluoride K2WO2F4 center dot H2O
Разночтения заглавия :авие SCOPUS: The role of structural and nonstructural water in oxyfluoride K2WO2F4 В· H2O
Место публикации : Phys. Solid State: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2011. - Vol. 53, Is. 12. - P2435-2440. - ISSN 1063-7834, DOI 10.1134/S1063783411120146
Примечания : Cited References: 16. - This work was supported by the Presidential Grant of the Russian Federation NSh-4645.2010.2, by the Russian Foundation for Basic Research, project no. 09-02-00062, and by the Integration Project of the Siberian Branch of the Russian Academy of Sciences no. 101.
Предметные рубрики: PHASE-TRANSITIONS
OXOPEROXOFLUORO COMPLEXES
MO V
CRYSTAL STRUCTURE
OXOFLUORO
(NH4)(2)NBOF5
(NH4)(2)WO2F4
MONOHYDRATE
DISORDER
Аннотация: X-ray structural and polarization optical investigations have been performed, and birefringence and rotation angles of the optical indicatrix phi (b) and phi (c) of the K2WO2F4 center dot H2O crystal have been measured in the temperature range of 100-600 K. The structure and symmetry of compounds at room temperature have been refined. It has been established that the layered crystal K2WO2F4 center dot H2O can exist in two states (A and B) depending on the atmospheric humidity and undergoes the sequence of reversible and irreversible phase transformations G (3)↔ G (2)↣ G (1)↣ G (0). The sequences of changes in the phase symmetry P (1) over bar↔C2/m↣ {4/nmm for samples A and m↔ C2/m↣P4/nmm for samples B havve been found. The second older proper ferroelastic phase transition (P(1) over bar↔ C2/m) at T-03 = 2700-290 K (G (3)↔ G (2)) is accompanied by twinning and appearance of the shift deformation x (6). The crystal system of the substance for the B crystals remains invariable after the second-order phase transition G (3) a dagger" G (2). The irreversible first-order phase transition G (2)↣ G (1) occurs in a temperature range T (02) a parts per thousand 350-380 K; it is accompanied by the loss of the crystallization water, which then is reduced easily from the atmosphere for a day. The substance decomposes at T (01) approximate to 510 K (G (1)↣ G (0)). The distinction between the A and B crystals has been explained by the presence or absence of free water in interlayer spacings.
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9.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Vasiliev A. D., Melnikova S.V., Isaenko L. I.
Заглавие : Orthorhombic aluminium oxyfluoride, AlOF
Место публикации : Acta Crystallogr. Sect. C-Cryst. Struct. Commun. - MALDEN: WILEY-BLACKWELL PUBLISHING, INC, 2009. - Vol. 65. - С. I20-I22. - APR. - ISSN 0108-2701, DOI 10.1107/S0108270109010671
Примечания : Cited Reference Count: 11. - Гранты: This work was supported by the RFFI (grant No. 07-0200442) and the Interdisciplinary Integration Project of the Siberian Branch of the Russian Academy of Sciences (No. 34).Финансирующая организация: RFFI [07-0200442]; Interdisciplinary Integration Project of the Siberian Branch of the Russian Academy of Sciences [34]
Аннотация: Crystals of the title compound were extracted from the bulk of grown SrAlF(5) crystals as unexpected inclusions that were identified as the long sought after aluminium oxyfluoride. The structure of AlOF is built up from tetrahedral and octahedral polyhedra. Each tetrahedron is bisected by a mirror plane, with the Al atom and two vertex anions in the plane. All tetrahedral vertices are positions of competing oxide and fluoride ions and are shared with octahedra. These shared vertices belong to two octahedral edges which join the octahedra to form infinite zigzag chains. The chains are strung along twofold screw axes that run parallel to the unit-cell b axis. The remaining two octahedral vertices are occupied only by fluoride ions. A small deficiency in the occupation of the octahedral Al position was suggested by the refinement. However, the stoichiometry of the compound is AlOF within experimental uncertainty. The Al-F(O) distances are separated into three groups with average values of 1.652 (3) (tetrahedra), 1.800(2) (octahedra) and 1.894 (2) angstrom (octahedra). This structure differs widely from the reported tetragonal phase Al(1-x)O(1-3x)F(1+ 3x) (x = 0.0886) [Kutoglu (1992). Z. Kristallogr. 199, 197-201], which consists solely of octahedral structural units.
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10.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Isaenko L.I., Merkulov A.A., Melnikova S.V., Pashkov V.M., Tarasova A.Yu.
Заглавие : Effect of the K↔Rb sub?stitution on structure and phase transition in mixed KxRb1-xPb2Br5 crystals
Место публикации : Cryst. Growth and Design. - 2009. - Vol. 9, № 5. - С. 2248-2251
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11.

Вид документа : Статья из сборника (однотомник)
Шифр издания :
Автор(ы) : Iskhakov R. S., Chekanova L. A., Denisova E. A., Bukaemskiy A.A., Melnikova S.V.
Заглавие : Synthesis and investigation of nanostructured Fe1-xNi x(P) columns deposited into porous polycarbona te matrix
Место публикации : Physics, Chemistry and Application of Nanostructures - Proceedings of the International Conference, NANOMEETING 2009. - 2009. - International Conference on Physics, Chemistry and Application of Nanostructures, NANOMEETING 2009 (26 May 2009 through 29 May 2009, Minsk, ) Conference code: 99438. - С. 264-267. - ISBN 9814280356 (ISBN); 9789814280358 (ISBN)
Ключевые слова (''Своб.индексиров.''): exchange constants--macroscopic anisotropy--morphological characterization--nano-structured fe--nanocrystallines--perpendicular anisotropy--porous polycarbonate membranes--shape anisotropy--magnetic anisotropy--nanostructures--nickel
Аннотация: Ferromagnetic Fe1-xNix(P) (x=24-65 at.%.) columns have been chemically deposited into porous polycarbonate membranes with pore diameters of 0.1-4 J.Im. The morphological characterization by TEM reveals the shape features in synthesized columns. Their magnetic perpendicular anisotropy due to the shape anisotropy of columns was observed. The dependence of macroscopic anisotropy on pore diameter and Ni content is analyzed. Approach to magnetic saturation curves and exchange constant of nanocrystalline fe?.xNix(P) columns deposited into porous pol}\:arbonate matrix are investigated.
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12.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Мисюль С. В., Мельникова, Светлана Владимировна, Бовина, Ася Федоровна, Лапташ Н. М.
Заглавие : Оптические и рентгеновские исследования симметрии искаженных фаз кристалла (NH4)3ZrF7
Место публикации : Физ. тверд. тела. - Санкт-Петербург: Наука, 2008. - Т. 50, № 10. - С. 1871-1876. - ISSN 0367-3294
Примечания : Библиогр.: 13
ГРНТИ : 29.19
Предметные рубрики:
Аннотация: Выращены монокристаллы (NH4)3ZrF7, проведены поляризационно-оптические и рентгеновские исследования порошков и кристаллических пластинок различных срезов в широком температурном интервале. Обнаружены фазовые переходы при температурах T1=280 K, T2=279.6 K, T3=260-265 K, T4=238 K (нагрев); T1=280 K, T2=269-270 K, T3=246 K, T4=235 K (охлаждение). Установлена последовательность изменения симметрии O5h(Z=4)=ftrightarrow D252h(Z=2)=ftrightarrow C32h(Z=2)=ftrightarrow C1i(Z=108)=ftrightarrowмоноклинная2(Z=216). Работа выполнена при финансовой поддержке гранта Президента РФ (грант НШ-4137.2006.2). PACS: 61.50.Ks, 64.70.Kb, 61.72.Mm
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13.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Мельникова, Светлана Владимировна, Лапташ Н. М.
Заглавие : Фазовые переходы в ромбическом оксофториде (NH4)2MoO2F4
Место публикации : Физ. тверд. тела. - 2008. - T. 50. - С. 493-496
Аннотация: Проведено измерение частотного спектра комплексной диэлектрической проницаемости (КДП) почвы в диапазоне частот от 0,5 до 15 ГГц в процессе замораживания - оттаивания. В рамках концепции обобщенной рефракционной модели диэлектрической проницаемости смеси (ОРМДС) проведен анализ фазовых переходов в процессе замораживания - оттаивания почвы, выделены два типа воды, одновременно существующие в почве, -связанная и свободная. Приведены температурные зависимости параметров модели Дебая для каждого типа воды и найдены параметры диэлектрической спектроскопической модели мерзлой и талой почв. Исследовано явление гистерезиса при фазовом переходе почвенной влаги.
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14.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Aleksandrovsky A.S., Bezmaternykh L.N., Bovina A.F., Gudim I.A., Kharlamova S.A., Krylov A.S., Melnikova S.V., Temerov V.Ye.
Заглавие : Unusual Valence States of Manganese Ions in Gadolinium Gallium Aluminum Borate Single Crystals
Место публикации : Известия высших учебных заведений. Физика. - 2008. - Т. 51, № 10/2. - С. 115-119
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15.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Kliava J., Malakhovskii A. V., Edelman I. S., Potseluyko A. M., Melnikova S. V., Petrakovskaja E. A., Zarubina T. V., Petrovskii G., Bruckental I., Yeshurun Y.
Заглавие : Reply to "Comment on 'Unusual magnetic transitions and nature of magnetic resonance spectra in oxide glasses containing gadolinium' "
Разночтения заглавия :авие SCOPUS: Reply to "comment on 'unusual magnetic transitions and nature of magnetic resonance spectra in oxide glasses containing gadolinium'"
Место публикации : Phys. Rev. B: AMER PHYSICAL SOC, 2006. - Vol. 74, Is. 2. - Ст.26404. - ISSN 1098-0121, DOI 10.1103/PhysRevB.74.026404
Примечания : Cited References: 8
Предметные рубрики: WALLED CARBON NANOTUBES
HYDROGEN
Аннотация: In this Reply we show that, contrary to the suggestion of Dubroca, Hack, and Hummel (DHH), the feature observed at ca. 55 K in the magnetic susceptibility of gadolinium-containing oxide glasses [as in our earlier paper, Kliava Phys. Rev. B 71, 104406 (2005)] cannot be due to a magnetic transition in oxygen contaminant. In support of this statement, we supply transformed data at low Gd content as well as magnetization curves for a series of glasses containing dysprosium oxide measured with the same superconducting quantum interference device as in our earlier paper. In all these cases the feature in question is absent. Thus, our previous assignment of the 55 K feature to a paramagnetic-to-ferromagnetic transition in Gd clusters in the glass remains the only one consistent with the experimental results.
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16.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Kliava J., Malakhovskii A. V., Edelman I. S., Potseluyko A. M., Petrakovskaja E. A., Melnikova S.V., Zarubina T. V., Petrovskii G., Bruckental Y., Yeshurun Y.
Заглавие : Unusual magnetic transitions and nature of magnetic resonance spectra in oxide glasses containing gadolinium
Место публикации : Phys. Rev. B: AMER PHYSICAL SOC, 2005. - Vol. 71, Is. 10. - Ст.104406. - ISSN 1098-0121, DOI 10.1103/PhysRevB.71.104406
Примечания : Cited References: 40
Предметные рубрики: ELECTRON-PARAMAGNETIC-RESONANCE
BORATE GLASSES
IONS
BEHAVIOR
GD3+
SPECTROSCOPY
SYSTEMS
GD-3+
FIELD
SHAPE
Ключевые слова (''Своб.индексиров.''): gadolinium--glass--lanthanide--oxide--anisotropy--article--chemical structure--concentration response--electron spin resonance--energy--magnetism--molecular physics--nanoparticle--phase transition--refraction index--temperature sensitivity
Аннотация: Magnetic susceptibility, electron paramagnetic resonance (EPR), and optical properties have been studied in a glass system {20La(2)O(3)-22Al(2)O(3)-23B(2)O(3)-35(SiO2+GeO2)} with a part of La2O3 substituted by Gd2O3 in different concentrations. Positive Weiss constants have been found in the more heavily doped glasses and ascribed to clustering of Gd3+ ions. Two magnetic phase transitions at 55 and 12 K were detected and ascribed, respectively, to ferromagnetic and antiferromagnetic clusters containing Gd ions. The overall shape of the EPR spectra shows the presence of clustering at the higher Gd contents. At low temperatures the cluster-related resonance signal is altered in shape, indicating an onset of magnetic anisotropy field. This signal is convincingly fitted to superparamagnetic resonance arising from ferromagnetic nanoparticles. The clustering, depending on the Gd concentration, correlates with a significant shift to lower energies of the strong optical absorption band edge, ascribed to a charge transfer transition between Gd ions. A nonmonotonous change of refractive index with the increase of the Gd content indicates changes in the glass matrix and in Gd cluster structure.
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17.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Gorev M. V., Flerov I. N., Melnikova S.V., Misyul S. V., Bovina A. F., Afanasiev M. L., Tresso A.
Заглавие : Ferroelectric phase transitions in cryolite (NH4)(3)ScF6
Коллективы : Конференция по физике сегнетоэлектриков
Место публикации : Izv. Akad. Nauk Ser. Fiz. - 2000. - Vol. 64, Is. 6. - P.1104-1110. - ISSN 1026-3489
Примечания : Cited References: 9
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18.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Melnikova S. V., Grankina V. A., Bandarenko G. V., Gorev M. V.
Заглавие : T-x phase diagram of solid solutions RbxK1-xLiSO4
Коллективы : International Seminar on Physics of Ferroelastics
Место публикации : Izv. Akad. Nauk Ser. Fiz. - 1998. - Vol. 62, Is. 8. - P.1537-1540. - ISSN 1026-3489
Примечания : Cited References: 4
Предметные рубрики: TRANSITIONS
CRYSTALS
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19.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Melnikova S. V., Zaitsev A. I.
Заглавие : Ferroelectric phase transition in Cs3Bi2I9
Место публикации : Phys. Solid State: MAIK NAUKA/INTERPERIODICA/SPRINGER, 1997. - Vol. 39, Is. 10. - P1652-1654. - ISSN 1063-7834, DOI 10.1134/1.1129882
Примечания : Cited References: 7
Аннотация: Single crystals of Cs3Bi2I9 have been grown. Polarized-optical, dielectric, and calorimetric studies have been performed, along with measurements of birefringence, and the coefficients of elasticity c(44), and linear expansion alpha over a wide temperature range. It is found that an intrinsic (pseudo-intrinsic) second-order phase transition to the ferroelastic phase takes place at T-0=220.0+/-0.6 K accompanied by a change of the crystal symmetry from 6/mmc to 2/m. The transition parameter depends linearly on the shear strain x(5) and varies with temperature according to a power law with exponent beta=0.5. (C) 1997 American Institute of Physics.
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20.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Melnikova S. V., Shabanova L. A., Zaitsev A. I., Parshikov S. A., Ageev O. A., Aleksandrov K. S.
Заглавие : Ferroelastic phase transition in Cs3Bi2I9 crystal
Место публикации : Ferroelectrics, Letters Section. - 1996. - Vol. 20, Is. 5-6. - P.163-167. - ISSN 0731-5171
Ключевые слова (''Своб.индексиров.''): birefringence--cesium compounds--crystal symmetry--crystals--differential scanning calorimetry--elasticity--ferroelectricity--permittivity--stiffness--twinning--cesium bismuth iodide--elastic constant--elastic stiffness--ferroelastic phase transition--phase transitions
Аннотация: Phase transition (PT) was found in Cs3Bi2I9 single crystal at T0=223 K. Optical birefringence, dielectric and elastic constants and differential scanning calorimetry have been studied. It was found that birefringence ?nc and twinning picture appeared on (001) - and (100) - plates below T0, as well as softening of elastic stiffness C44 above T0. It allows to classify the PT as proper ferroelastic one with symmetry change 6/mmm - 2/m. В© 1996 OPA (Overseas Publishers Association) Amsterdam B.V. Published in The Netherlands under license by Gordon and Breach Science Publishers SA.
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