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Каталог книг и брошюр библиотеки ИФ СО РАН

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Труды сотрудников ИФ СО РАН

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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Aleksandrov K. S., Bartolome J., Gorev M. V., Flerov I. N.
Заглавие : Hydrostatic pressure effect on phase transitions in perovskites with ammonium cations
Место публикации : Phys. Status Solidi B. - 2000. - Vol. 217, Is. 2. - P.785-791. - ISSN 0370-1972, DOI 10.1002/(SICI)1521-3951(200002)217:2785::AID-PSSB7853.0.CO;2-Y
Примечания : Cited References: 36
Предметные рубрики: XMF3 CUBIC PEROVSKITES
THERMAL-PROPERTIES
HEAT-CAPACITY
TEMPERATURE DEPENDENCE
DIELECTRIC PROPERTIES
X-RAY
NH4ZNF3
NH4MNCL3
NH4COF3
NH4CDF3
Аннотация: The pressure dependence of the structural phase transition temperature has been measured for the powder samples of NH4MgF3, NH4ZnF3, NH4MnF3, NH4CoF3, NH4CdF3, and NH4MnCl3 perovskites in the pressure range 0 to 600 MPa. It was found that the values of dT(0)/dP are negative for the Mg, Zn. Co. Mn trifluorides and positive for NH4CdF3 and NH4MnCl3. Comparison with the known data for other halide and oxide perovskites allowed to conclude that the sign of dT(0)/dP is correlated with the value of the Goldschmidt tolerance factor of the perovskite, and its value is closely related to the temperature and mechanism of the transition.
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Вид документа : Статья из сборника (однотомник)
Шифр издания :
Автор(ы) : Vtyurin A. N., Isaenko L. I., Krylova S. N., Yelisseyev A., Shebanin A. P., Turchin P. P., Zamkova N. G., Zinenko V. I.
Заглавие : Raman spectra and elastic properties of KPb2Cl5 crystals
Место публикации : 11th International Conference on Phonon Scattering in Condensed Matter (PHONONS 2004) (JUL 25-30, 2004, St Petersburg, RUSSIA): WILEY-V C H VERLAG GMBH, 2004. - P3142-3145. - ISBN 3-527-40588-7, DOI 10.1002/pssc.200405401
Примечания : Cited References: 10
Предметные рубрики: LATTICE-DYNAMICS
Ключевые слова (''Своб.индексиров.''): computer simulation--crystal structure--eigenvalues and eigenfunctions--halogen compounds--nonlinear optics--phonons--potassium compounds--vectors--elastic constants--heavy cations--ionic electron envelopes--ionic interactions--raman scattering
Аннотация: Raman scattering spectra and elastic constants of KPb2Cl5 crystals have been studied. The results obtained are interpreted in terms of the ab initio lattice dynamics model taking into account multipole moments of ionic electron envelopes. The experimental results have been found to be in good agreement with numerical simulation; the narrow phonon spectra are shown to be due to a considerable contribution of heavy cations into the eigenvectors of the higher frequency lattice modes.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Krakhalev M. N., Prishchepa O. O., Zyryanov V. Ya.
Заглавие : Inverse mode of ion-surfactant method of director reorientation inside nematic droplets
Место публикации : Mol. Cryst. Liquid Cryst. - 2009. - Vol. 512, Is. 1. - P.1998-2003. - ISSN 1542-1406, DOI 10.1080/15421400903050814
Примечания : Cited Reference Count: 8. - Гранты: This work was partially supported by the grants Nos. NSh-3818.2008.3; 02.740.11.0220, and No. 08-03-01007 of RFBR, and Nos. 27.1; 110; 144 of SB RAS. M. Krakhalev acknowledges the financial support from K. I. Zamaraev MBN Foundation. O. Prishchepa acknowledges the financial support from Russian Science Support Foundation.Финансирующая организация: RFBR [NSh-3818.2008.3, 02.740.11.0220, 08-03-01007]; SB RAS [27.1; 110; 144]; Zamaraev MBN Foundation; Russian Science Support Foundation
Ключевые слова (''Своб.индексиров.''): electrically commanded surfaces--ion surfactant--nematic--polymer dispersed liquid crystals--surface anchoring--electrically commanded surfaces--ion surfactant--nematic--polymer dispersed liquid crystals--surface anchoring--applied voltages--crossed polarizers--director fields--director reorientation--droplet structure--electrically commanded surfaces--high concentration--homeotropic--initial state--ionic modification--liquid-crystal droplets--nematic droplets--nematic polymer--surface-active cations--surface-anchoring--trimethyl--ammonium compounds--cationic surfactants--crystals--drop formation--dyes--ionization of liquids--ions--liquid crystal displays--liquid crystals--liquids--nematic liquid crystals
Аннотация: Inverse mode of a novel electrooptical effect caused by the ionic modification of boundary conditions has been studied for liquid crystal droplets. We have considered the droplets of nematic 5CB doped with cationic surfactant cetyl-trimethyl-ammonium-bromide and dispersed in polyvinyl alcohol. In the initial state the surface anchoring was normal on the whole interface due to the high concentration of homeotropic surfactant. Applied voltage results in the purification of a section of the interface from the surface-active cations thereby restoring here a tangential anchoring and stimulating the significant transformation of droplet structure. At that three different types of director field distribution can be realized within the same droplet. The proper textures of the droplet both in the crossed polarizers and without analyzer are considered.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Volkov N. V., Eremin E. V., Sablina K. A., Sapronova N. V.
Заглавие : Dielectric properties of a mixed-valence Pb3Mn7O15 manganese oxide
Коллективы :
Разночтения заглавия :авие SCOPUS: Dielectric properties of a mixed-valence Pb3Mn7O 15 manganese oxide
Место публикации : J. Phys.: Condens. Matter: IOP PUBLISHING LTD, 2010. - Vol. 22, Is. 37. - Ст.375901. - ISSN 0953-8984, DOI 10.1088/0953-8984/22/37/375901
Примечания : Cited References: 14. - This study was supported by the Russian Foundation for Basic Research 'Siberia', project No. 09-02-98003, and the Siberian Branch of the Russian Academy of Sciences, integration project No. 101.
Ключевые слова (''Своб.индексиров.''): cation--lead--manganese derivative--oxide--article--chemical model--chemistry--crystallization--electric conductivity--electronics--methodology--temperature--cations--crystallization--electric conductivity--electronics--lead--manganese compounds--models, chemical--oxides--temperature--ac electric field--analysis of resistivity--carrier hopping--charge ordering--complex dielectric constant--crystal site--debye models--dielectric constants--dielectric spectra--frequency windows--lattice sites--low frequency--manganese ions--mixed valence--mixed valence state--relaxation behaviors--temperature range--electric fields--manganese--manganese oxide--permittivity--single crystals--crystal symmetry
Аннотация: We investigated the low-frequency dielectric properties of a Pb3Mn7O15 single crystal with manganese ions in the mixed-valence state (Mn3+/Mn4+). Dielectric relaxation was found in the frequency window from 20 to 100 kHz in the temperature range 110-180 K. The dielectric spectra of the crystal were analyzed using a Debye model. Estimations made within the model and analysis of resistivity data suggest that the relaxation behavior of the dielectric constant is related to polaronic charge carrier hopping. Around 250 K, charge ordering occurs in the crystal when the Mn3+ and Mn4+ ions are arranged in a specific order among the crystal sites. With a decrease in temperature, an ac electric field can induce a charge hop between the equivalent lattice sites available, related to crystal symmetry. This hopping is equivalent to the reorientation of an electric dipole that yields Debye-type behavior of the complex dielectric constant. The observed anisotropy in the behavior of the dielectric properties and resistivity can be attributed to a pronounced two-dimensional character of the crystal structure.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Aplesnin S. S., Kharkov A. M., Romanova O. B., Sitnikov M. N., Eremin E. V., Gorev M. V., Yanushkevich K. I., Sokolov V. V., Pichugin A. Y.
Заглавие : Spin state of cations and magnetoelastic effect in the Mn1-X YbXS
Место публикации : J. Magn. Magn. Mater.: Elsevier, 2014. - Vol. 352, Is. 1. - P.1-5. - ISSN 0304-8853, DOI 10.1016/j.jmmm.2013.09.061
Примечания : Cited References: 15
Ключевые слова (''Своб.индексиров.''): spin state--magnetization curve--magnetoelastic effect--valence fluctuations
Аннотация: Magnetic moment and magnetization curves of the Mn1−XYbXS (0.05≤Х≤0.2) solid solutions have been experimentally studied at temperatures 4–700 K in magnetic fields up to 9 T. Spin states of manganese and ytterbium ions, the concentration region with the bi- and trivalent states of ytterbium ions are determined. The nonlinear field behavior of the magnetization at X=0.05, the sharp Curie temperature drop and a decrease in the Neel temperature were found. The decrease in the coefficient of thermal expansion with increasing concentration of ytterbium in the magnetically ordered region and the interrelation between the magnetic and elastic subsystems of the Mn1–XYbXS solid solutions have been established.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Molokeev M. S., Golovnev N. N., Vereshchagin S. N., Atuchin V. V.
Заглавие : Crystal structure, spectroscopic and thermal properties of the coordination compounds M(1,3-diethyl-2-thiobarbiturate) M = Rb+, Cs+, Tl+ and NH4+
Место публикации : Polyhedron: Elsevier, 2015. - Vol. 98. - P.113-119. - ISSN 0277-5387, DOI 10.1016/j.poly.2015.05.048
Примечания : Cited References: 43. - The study was carried out within the public task of the Ministry of Education and Science of the Russian Federation for research engineering of the Siberian Federal University in 2015. V.V.A. is grateful to the Ministry of Education and Science of the Russian Federation for financial support of the investigation.
Предметные рубрики: 2-THIOBARBITURIC ACID
THIOBARBITURIC ACID
1,3-DIETHYL-2-THIOBARBITURIC ACID
HYDROGEN-BOND
COMPLEXES
DIFFRACTION
CHEMISTRY
NETWORKS
LIGAND
SERIES
Ключевые слова (''Своб.индексиров.''): 1,3-diethyl-2-thiobarbituric acid--alkali ion thallium(i) and ammonium cations--coordination compounds--thermal analysis--x-ray diffraction
Аннотация: Four new compounds of 1,3-diethyl-2-thiobarbituric acid (C8H11N2O2S, Hdetba) with Rb+, Cs+, Tl+ and NH4+ ions were prepared by Hdetba neutralization with the metal carbonates or ammonium hydroxide in aqueous solution. The colorless crystals have been investigated using X-ray diffraction techniques, differential scanning calorimetry, thermogravimetry and infrared spectroscopy. The coordination compounds of MDetba with M = Rb, Cs and Tl crystallize in the orthorhombic space group P212121, but compound NH4Detba crystallizes in the triclinic space group P1¯. The MDetba structures were compared at the molecular and supramolecular levels. The Detba- ion in the NH4+ compound forms conformer (A) with two diethyl groups on one side of the ion ring, whereas the Detba- ion in the Rb(I), Cs(I) and Tl(I) compounds forms conformer (B) with two diethyl groups on different sides of the ring. The results of IR spectroscopy and thermal analysis are consistent with the X-ray data. © 2015 Elsevier Ltd.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Chen M., Xia Z., Molokeev M. S., Liu Q.
Заглавие : Reply to comment on “Tuning of photoluminescence and local structures of substituted cations in xSr2Ca(PO4)2-(1-x)Ca10Li(PO4)7:Eu2+ phosphors”
Место публикации : Chem. Mater.: American Chemical Society, 2017. - Vol. 29, Is. 8. - P.3803-3805. - ISSN 08974756 (ISSN), DOI 10.1021/acs.chemmater.7b01261
Примечания : Cited References: 7
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Chen M., Xia Z., Molokeev M. S., Wang T., Liu Q.
Заглавие : Tuning of photoluminescence and local structures of substituted cations in xSr2Ca(PO4)2-(1 - x)Ca10Li(PO4)7:Eu2+ phosphors
Место публикации : Chem. Mater.: American Chemical Society, 2017. - Vol. 29, Is. 3. - P.1430-1438. - ISSN 08974756 (ISSN), DOI 10.1021/acs.chemmater.7b00006
Примечания : Cited References: 37. - The present work was supported by the National Natural Science Foundation of China (Grants 91622125 and 51572023), Natural Science Foundations of Beijing (2172036), and Fundamental Research Funds for the Central Universities (FRF-TP-15-003A2).
Ключевые слова (''Своб.индексиров.''): calcium--energy transfer--europium--light emission--lithium--luminescence--phosphors--photoionization--photoluminescence--single crystals--composition ranges--crystal-field splitting--luminescence measurements--non-linear variation--photoionization process--polyhedra distortion--rare earth doped solids--temperature dependent--solid solutions
Аннотация: Local structure modification in solid solution is an essential part of photoluminescence tuning of rare earth doped solid state phosphors. Herein we report a new solid solution phosphor of Eu2+-doped xSr2Ca(PO4)2-(1 - x)Ca10Li(PO4)7 (0 ≤ x ≤ 1), which share the same β-Ca3(PO4)2 type structure in the full composition range. Depending on the x parameter variation in xSr2Ca(PO4)2-(1 - x)Ca10Li(PO4)7:Eu2+, the vacancies generated in the M(4) site enable the nonlinear variation of cell parameters and volume, and this increases the magnitude of M(4)O6 polyhedra distortion. The local structure modulation around the Eu2+ ions causes different luminescent behaviors of the two-peak emission and induces the photoluminescence tuning. The shift of the emission peaks in the solid solution phosphors with different compositions has been discussed. It remains invariable at x ≤ 0.5, but the red-shift is observed at x 0.5 which is attributed to combined effect of the crystal field splitting, Stokes shift, and energy transfer between Eu2+ ions. The temperature-dependent luminescence measurements are also performed, and it is shown that the photoionization process is responsible for the quenching effect.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Ming, Zhiqiang, Qiao, Jianwei, Molokeev M. S., Zhao, Jing, Swart, Hendrik C., Xia, Zhiguo
Заглавие : Multiple substitution strategies toward tunable luminescence in Lu2MgAl4SiO12:Eu2+ phosphors
Место публикации : Inorg. Chem. - 2020. - Vol. 59, Is. 2. - P.1405-1413. - ISSN 0020-1669, DOI 10.1021/acs.inorgchem.9b03142. - ISSN 1520-510X (eISSN)
Примечания : Cited References: 31. - This research is supported by the National Natural Science Foundation of China (Grants 51972118, 51722202, and 51572023), Natural Science Foundations of Beijing (Grant 2172036), and Fundamental Research Funds for the Central Universities (Grant FRF-TP-18-002C1)
Предметные рубрики: Physical and chemical processes
Phosphors
Luminescence
Cations
Ions
Аннотация: The equivalent or heterovalent substitution strategy is an efficient way to stimulate photoluminescence tuning or to optimize the luminescence performances of phosphor materials. Garnet-type compounds receive much attention as phosphor hosts because of their flexible structural frameworks. Herein, a garnet-type Lu2MgAl4SiO12:Eu2+ phosphor with broad-band blue-green emission is first explored with two-site occupation by varying the Eu2+ content. Two host-substitution approaches to controlling the luminescence behavior of Lu2MgAl4SiO12:Eu2+ phosphor are implemented. The cation substitution strategy of Ca2+ for Mg2+ achieves tunable emission from 463 to 503 nm together with broadening emission bands in Lu2Mg1–yCayAl4SiO12:Eu2+ phosphors. Moreover, chemical unit cosubstitution of [Ca2+–Ge4+] replacing [Lu3+–Al3+] results in Lu2–zCazMgAl4–zGezSiO12:Eu2+ phosphors, which induce a red shift of the emission peak of about 60 nm and a broadening in the emission spectra with increasing Ca2+ and Ge4+ concentrations. The possible photoluminescence tuning mechanism is ascribed to the coordination sphere variation in the EuO8 polyhedron depending on the changing neighboring cations. The proposed approaches on equivalent or heterovalent substitution can contribute to the development of Eu2+-activated garnet-type phosphors with regulation of the luminescence performance and further initiate research discovering new phosphors for white-light-emitting diodes.
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