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: (<.>K=Europium<.>)

Общее количество найденных документов : 33
Показаны документы с 1 по 20

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Hu T., Gao Y., Molokeev M. S., Xia Z., Zhang Q.
Заглавие : Non-stoichiometry in Ca2Al2SiO7 enabling mixed-valent europium toward ratiometric temperature sensing
Место публикации : Sci. China Mater. - 2019. - Vol. 62, Is. 12. - P.1807–1814. - ISSN 20958226 (ISSN), DOI 10.1007/s40843-019-1202-x
Примечания : Cited References: 53. - This work was supported by the National Natural Science Foundation of China (51722202, 51972118 and 51572023), the Guangdong Provincial Science & Technology Project (2018A050506004), and Innovation Projects of Department of Education of Guangdong Province (2018KQNCX265).
Аннотация: Eu2+/Eu3+ mixed-valence couple co-doped material holds great potential for ratiometric temperature sensing owing to its different electronic configurations and electron-lattice interaction. Here, the correlation of nonstoichiometry in chemical composition, phase structures and luminescence propertis of Ca2Al2Si1−xO7:Eu is discussed, and controlled Eu2+/Eu3+ valence and tunable emission appear with decreasing Si content. It is found that the 2Ca2+ + Si4+ ↔ Eu2+ + Eu3+ + Al3+ cosubstitution accounts for the structural stability and charge balance mechanism. Benefiting from the diverse thermal dependent emission behaviors of Eu2+ and Eu3+, Ca2Al2Si1−xO7:Eu thermometer exhibits excellent temperature sensing performances with the maximum absolute and relative sensitivity being 0.024 K−1 (at 303 K) and 2.46% K−1 (at 443 K) and good signal discriminability. We propose that the emission quenching of Eu2+ is ascribed to 5d electrons depopulation through Eu2+/Eu3+ intervalence charge transfer state, while the quenching of Eu3+ comes from multi phonon relaxation. Our work demonstrates the potential of Ca2Al2Si1−xO7:Eu for noncontact optical thermometry, and also highlights mixed valence europium containing com pounds toward temperature sensing.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Denisenko Y. G., Molokeev M. S., Krylov A. S., Aleksandrovsky A. S., Oreshonkov A. S., Atuchin V. V., Azarapin N. O., Plyusnin P. E., Sal'nikova E. I., Andreev O. V.
Заглавие : High-temperature oxidation of europium (II) sulfide
Место публикации : J. Ind. Eng. Chem. - 2019. - Vol. 79. - P.62-70. - ISSN 1226086X (ISSN) , DOI 10.1016/j.jiec.2019.05.006
Примечания : Cited References: 68. - The authors are grateful for the support from RFBR ( 18-02-00754 , 18-08-00985 , and 18-32-20011 ). This study was also supported by the Russian Science Foundation (project 19-42-02003 , in part of conceptualization).
Аннотация: The process of high-temperature oxidation of EuS in the air was explored in the temperature range of 500–1000 °C. The oxidation reaction enthalpy was determined (ΔH0exp = −1718.5 kJ/mol). The study of oxidation products allowed to establish the mechanism of EuS oxidation with oxygen. At 500–600 °C, EuS is oxidized to a mixture of Eu3+-containing compounds (Eu3S4, Eu2O2S). In the range of 700–1000 °C, only europium oxysulfate Eu2O2SO4 is formed. The structure refinement for Eu2O2SO4 was performed by the Rietveld method. The luminescence intensity of europium oxysulfate Eu2O2SO4 with characteristic 4f-4f transitions from the 5D0 state was investigated as a function of oxidation temperature.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Denisova L. T., Molokeev M. S., Irtyugo L. A., Beletskii V. V., Kargin, Yu. F., Denisov V. M.
Заглавие : Synthesis, structure, and thermophysical properties of EuGaGe2O7
Место публикации : Inorg. Mater. - 2020. - Vol. 56, Is. 8. - P.854-858. - ISSN 0020-1685, DOI 10.1134/S002016852008004X. - ISSN 1608-3172(eISSN)
Примечания : Cited References: 18
Предметные рубрики: TEMPERATURE HEAT-CAPACITY
THERMODYNAMIC PROPERTIES
CRYSTAL-STRUCTURE
Аннотация: The europium gallium germanate EuGaGe2O7 has been prepared by solid-state reaction in air in the temperature range 1273–1473 K using a stoichiometric mixture of Eu2O3, Ga2O3, and GeO2. Its crystal structure has been determined by X-ray diffraction (sp. gr. P21/c, a = 7.1693(7) Å, b = 6.57008(6) Å, c = 12.7699(1) Å, β = 117.4522(5)°, V = 533.768(8) Å3). The heat capacity of polycrystalline samples has been determined by differential scanning calorimetry in the temperature range 350–1053 K and the experimental data have been used to calculate the thermodynamic properties (enthalpy increment, entropy change, and reduced Gibbs energy change) of EuGaGe2O7.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из сборника (однотомник)
Шифр издания :
Автор(ы) : Denisenko Yu. G., Atuchin V. V., Molokeev M. S., Aleksandrovsky A. S., Oreshonkov A. S., Andreev O. V.
Заглавие : Synthesis, crystall structure, thermochemical and luminescent-spectral properties of europium sulphates
Коллективы : Mendeleev Congress on General and Applied Chemistry, Менделеевский съезд по общей и прикладной химии, Российская академия наук, Российское химическое общество им. Д.И. Менделеева, Российский фонд фундаментальных исследований, Санкт-Петербургский государственный университет, Санкт-Петербургский горный университет, Российский союз химиков, Институт физической химии и электрохимии имени А.Н. Фрумкина РАН
Место публикации : XXI Mendeleev Congress on General and Applied Chemistry: Book of abstracts : in 6 vols. - 2019. - Vol. 2b. - P.90
Примечания : Cited References: 2
Материалы съезда,
Материалы съезда
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Chen M., Xia Z., Molokeev M. S., Lin C. C., Su C., Chuang Y. -C., Liu Q.
Заглавие : Probing Eu2+ luminescence from different crystallographic sites in Ca10M(PO4)7:Eu2+ (M = Li, Na, and K) with β-Ca3(PO4)2-type structure
Место публикации : Chem. Mater.: American Chemical Society, 2017. - Vol. 29, Is. 17. - P.7563-7570. - ISSN 08974756 (ISSN), DOI 10.1021/acs.chemmater.7b02724
Примечания : Cited References: 34. - The present work was supported by the National Natural Science Foundation of China (Grants 51722202, 91622125, and 51572023), Natural Science Foundations of Beijing (2172036), and Fundamental Research Funds for the Central Universities (FRF-TP-16-002A3). C.C.L. and C.C.S. acknowledge the financial support from the Ministry of Science and Technology of Taiwan (Contract No. MOST 104-2113-M-027-007-MY3), and M. Molokeev acknowledges support of the Russian Foundation for Basic Research (17-52-53031).
Ключевые слова (''Своб.индексиров.''): calcium--doping (additives)--excited states--light emission--lithium--luminescence--phosphors--photoluminescence--positive ions--rietveld refinement--single crystals--color tuning--crystallographic sites--different distributions--emission bands--local environments--long wavelength bands--luminescent centers--power diffraction data--europium
Аннотация: Eu2+ local environments in various crystallographic sites enable the different distributions of the emission and excitation energies and then realize the photoluminescence tuning of the Eu2+ doped solid state phosphors. Herein we report the Eu2+-doped Ca10M(PO4)7 (M = Li, Na, and K) phosphors with β-Ca3(PO4)2-type structure, in which there are five cation crystallographic sites, and the phosphors show a color tuning from bluish-violet to blue and yellow with the variation of M ions. The difference in decay rate monitored at selected wavelengths is related to multiple luminescent centers in Ca10M(PO4)7:Eu2+, and the occupied rates of Eu2+ in Ca(1), Ca(2), Ca(3), Na(4), and Ca(5) sites from Rietveld refinements using synchrotron power diffraction data confirm that Eu2+ enters into four cation sites except for Ca(5). Since the average bond lengths d(Ca-O) remain invariable in the Ca10M(PO4)7:Eu2+, the drastic changes of bond lengths d(M-O) and Eu2+ emission depending on the variation from Li to Na and K can provide insight into the distribution of Eu2+ ions. It is found that the emission band at 410 nm is ascribed to the occupation of Eu2+ in the Ca(1), Ca(2), and Ca(3) sites with similar local environments, while the long-wavelength band (466 or 511 nm) is attributed to Eu2+ at the M(4) site (M = Na and K). We show that the crystal-site engineering approach discussed herein can be applied to probe the luminescence of the dopants and provide a new method for photoluminescence tuning.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Zhao M., Xia Z., Molokeev M. S., Ning L., Liu Q.
Заглавие : Temperature and Eu2+-doping induced phase selection in NaAlSiO4 polymorphs and the controlled yellow/blue emission
Место публикации : Chem. Mater.: American Chemical Society, 2017. - Vol. 29, Is. 15. - P.6552-6559. - ISSN 08974756 (ISSN), DOI 10.1021/acs.chemmater.7b02548
Примечания : Cited References: 48. - The present work was supported by the National Natural Science Foundation of China (Grants 91622125 and 51572023 and 11574003), Natural Science Foundations of Beijing (2172036), and Fundamental Research Funds for the Central Universities (FRF-TP-16-002A3). L.N. acknowledges the support from the Special and Excellent Research Fund of Anhui Normal University.
Ключевые слова (''Своб.индексиров.''): chemical modification--coordination reactions--europium--light emitting diodes--photoluminescence--functional properties--high color rendering index--local coordination structures--near ultraviolet excitations--structural transformation--synthesis temperatures--temperature dependent--white light emitting diodes--density functional theory
Аннотация: The union of temperature-dependent phase transition and relating structural transformation via modification of chemical compositions is of fundamental importance for the discovery of new materials or their functional properties optimization. Herein, the synthesis temperature and Eu2+-doping content induced phase selection and variations of the local structures in nepheline, low-carnegieite and high-carnegieite types of NaAlSiO4 polymorphs were studied in detail. The luminescence of Eu2+ in low-carnegieite and nepheline phases shows blue (460 nm) and yellow (540 nm) broad-band emissions, respectively, under near-ultraviolet excitation. The photoluminescence evolution can be triggered by the different synthesis temperatures in relation to the Eu2+-doping concentration, as corroborated by density functional theory calculations on the local coordination structures and corresponding mechanical stabilities in terms of the Debye temperature. The fabricated white light-emitting diode device with high color rendering index demonstrates that the multicolor phosphors from one system provides a new gateway for the photoluminescence tuning. © 2017 American Chemical Society.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Atuchin V. V., Aleksandrovsky A. S., Bazarov B. G., Bazarova J. G., Chimitova, Olga D., Denisenko, Yuriy G., Gavrilova T. A., Krylov A. S., Maximovskiy, Eugene A., Molokeev M. S., Oreshonkov A. S., Pugachev, Alexey M., Surovtsev, Nikolay V.
Заглавие : Exploration of structural, vibrational and spectroscopic properties of self-activated orthorhombic double molybdate RbEu(MoO4)2 with isolated MoO4 units
Коллективы : RFBR [16-52-48010, 17-52-53031, 18-03-00557]; Ministry of Science and Higher Education of the Russian Federation [0339-2016-0007]; Act 211 Government of the Russian Federation [02.A03.21.0011]; Ministry of Education and Science of the Russian Federation [4.1346.2017/4.6]
Место публикации : J. Alloy. Compd. - 2019. - Vol. 785. - P.692-697. - ISSN 0925-8388, DOI 10.1016/j.jallcom.2019.01.013. - ISSN 1873-4669(eISSN)
Примечания : Cited References: 42. - The reported study was funded by RFBR according to research projects 16-52-48010, 17-52-53031 and 18-03-00557. Besides, this study was supported by the Ministry of Science and Higher Education of the Russian Federation (project 0339-2016-0007). The work was supported by Act 211 Government of the Russian Federation, contract No 02.A03.21.0011. Additionally, the work was partially supported by the Ministry of Education and Science of the Russian Federation (4.1346.2017/4.6).
Предметные рубрики: MORPHOLOGY-CONTROLLED SYNTHESIS
LUMINESCENCE PROPERTIES
Ключевые слова (''Своб.индексиров.''): rubidium europium molybdate--solid state reaction--rietveld refinement--dsc--raman luminescence
Аннотация: RbEu(MoO4)2 is synthesized by the two-step solid state reaction method. The crystal structure of RbEu(MoO4)2 is defined by Rietveld analysis in space group Pbcn with cell parameters a = 5.13502(5), b = 18.8581(2) and c = 8.12849(7) Å, V = 787.13(1) Å3, Z = 4 (RB = 0.86%). This molybdate possesses its phase transition at 817 K and melts at 1250 K. The Raman spectra were measured with the excitation at λ = 1064 and 514.5 nm. The photoluminescence spectrum is evaluated under the excitation at 514.5 nm. The absolute domination of hypersensitive 5D0→7F2 transition is observed. The ultranarrow 5D0→7F0 transition in RbEu(MoO4)2 is positioned at 580.2 nm being 0.2 nm blue shifted, with respect to that in Eu2(MoO4)3.
Смотреть статью,
WOS,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Denisenko Y. G., Aleksandrovsky A. S., Atuchin V. V., Krylov A. S., Molokeev M. S., Oreshonkov A. S., Shestakov N. P., Andreev O. V.
Заглавие : Exploration of structural, thermal and spectroscopic properties of self-activated sulfate Eu2(SO4)3 with isolated SO4 groups
Место публикации : J. Ind. Eng. Chem. - 2018. - Vol. 68. - P.109-116. - ISSN 1226086X (ISSN), DOI 10.1016/j.jiec.2018.07.034
Примечания : Cited References: 83. - This work was supported by the Russian Foundation for Basic Research ( 16-52-48010 , 17-52-53031 ). The equipments of the Collective Use Center — Kirensky Institute of Physics, Federal Research Center KSC Siberian Branch Russian Academy of Sciences [ http://ccu.kirensky.ru/ ] was used.
Ключевые слова (''Своб.индексиров.''): europium sulfate--synthesis--structure--thermal analysis--photoluminescence
Аннотация: Eu2(SO4)3 was synthesized by chemical precipitation method and the crystal structure was determined by Rietveld analysis. The compound crystallizes in monoclinic space group С2/с. In the air environment, Eu2(SO4)3 is stable up to 670 °C. The sample of Eu2(SO4)3 was examined by Raman, Fourier-transform infrared absorption and luminescence spectroscopy methods. The low site symmetry of SO4 tetrahedra results in the appearance of the IR inactive ν1 mode around 1000 cm−1 and ν2 modes below 500 cm−1. The band intensities redistribution in the luminescent spectra of Eu3+ ions is analyzed in terms of the peculiarities of its local environment.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Shaikhutdinov K. A., Popkov S. I., Semenov S. V., Balaev D. A., Dubrovskiy A. A., Sablina K. A., Volkov N. V.
Заглавие : Low-temperature resistivity of polycrystalline (La0.5Eu 0.5)0.7Pb0.3MnO3 in a magnetic fields
Место публикации : J. Phys. Conf. Ser. - 2010. - Vol. 200, Is. SECTION 5. - ISSN 17426588 (ISSN) , DOI 10.1088/1742-6596/200/5/052025
Ключевые слова (''Своб.индексиров.''): antiferromagnetic grains--comparative analysis--ferromagnetic grain--low temperatures--polycrystalline--specific heat measurement--spin dependent tunneling--transport and magnetic properties--antiferromagnetism--electric resistance--europium--grain boundaries--grain size and shape--lanthanum compounds--lead--magnetic field effects--magnetic properties--magnetoresistance--manganese oxide--single crystals--thermal variables measurement--lanthanum
Аннотация: The effect of grain boundaries on magnetoresistance (MR) of manganites have been investigated by the comparative analysis of the properties of single-crystal and polycrystalline (La0.5Eu0.5) 0.7Pb0.3MnO3. While MR of the single crystal is maximum near the Curie temperature and vanishes in the low-temperature region, the polycrystalline (La0.5Eu0.5)0.7Pb 0.3MnO3 sample exhibits high MR in the low-temperature region. In order to clarify the origin of the low-temperature MR, the transport and magnetic properties of the polycrystalline (La0.5Eu 0.5)0.7Pb0.3MnO3 in magnetic fields have been supplemented by study of magnetic properties and specific heat measurements. The results obtained could be attributed to spin-dependent tunneling between ferromagnetic grains through insulating antiferromagnetic grain boundaries. © 2010 IOP Publishing Ltd.
Scopus,
eLibrary
Найти похожие

10.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Kartashev A. V., Flerov I. N., Volkov N. V., Sablina K. A.
Заглавие : Heat capacity and magnetocaloric effect in manganites (La1-yEuy)(0.7)Pb0.3MnO3 (y:0.2; 0.6)
Место публикации : J. Magn. Magn. Mater. - 2010. - Vol. 322, Is. 6. - P.622-627. - MAR. - ISSN 0304-8853, DOI 10.1016/j.jmmm.2009.10.026
Примечания : Cited Reference Count: 17. - Гранты: This work was supported by the Krasnoyarsk's regional sciences foundation and RFBR in the framework of project "Siberia''(Grant no. 09-02-98001), by Integrational project of Siberian and Far Eastern Departments of RAS(no. 101) and by Council on Grants from the President of the Russian Federation for Support of Leading Scientific Schools(Projectno. NSh-1011.2008.2). Dr Maxim S. Molokeev is acknowledged for the X-raycharacterization of the samples.Финансирующая организация: Krasnoyarsk's regional sciences foundation [09-02-98001]; Siberian and Far Eastern Departments [101]; Russian Federation [NSh-1011.2008.2]
Предметные рубрики:
Ключевые слова (''Своб.индексиров.''): manganites--magnetic phase transition--heat capacity--magnetocaloric effect--heat capacity--magnetic phase transition--magnetocaloric effect--manganites--adiabatic calorimeters--heat capacities--magnetic phase transitions--magneto-caloric effects--magnetocaloric effect--multi-element--nonmagnetics--relative cooling power--temperature range--europium--lead--manganese compounds--oxide minerals--specific heat--phase transitions
Аннотация: Heat capacity and intensive magnetocaloric effect (MCE) in manganites (La1-yEuy)(0.7)Pb0.3MnO3[y=0.2; 0.6] (LEPM) were investigated by means of adiabatic calorimeter. The heat capacity anomaly as well as the values of both the intensive (Delta T-AD) and the extensive (Delta S-MCE) MCE were found to decrease upon increased replacement of La with nonmagnetic Eu. However, because of widening of the MCE peaks, the LEPM compounds show the relative cooling power, RCP/Delta H, comparable to other solid solutions of manganites. Owing to strong effect of Eu - La substitution on the Curie temperature, LEPM might have potential as the solid state refrigerants in multi-element cooling apparatus operating in a wide temperature range. (C) 2009 Elsevier B.V. All rights reserved.
WOS,
Scopus,
eLibrary
Найти похожие

11.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Denisova L. T., Molokeev M. S., Irtyugo L. A., Belousova N. V., Denisov V. M.
Заглавие : Crystal structure and thermodynamic properties of germanate CuEu2Ge2O8
Место публикации : Phys. Solid State. - 2022. - Vol. 64, Is. 12. - P.2045-2048. - ISSN 10637834 (ISSN), DOI 10.21883/PSS.2022.12.54406.460. - ISSN 10906460 (eISSN)
Примечания : Cited References: 18. - The work has been partially funded within the framework of the state science assignment of Federal State Independent Institution for Higher Education ”Siberian Federal University“, project number FSRZ-2020-0013
Аннотация: Copper-europium germanate CuEu2Ge2O8 was obtained from the initial CuO, Eu2O3 and GeO2 oxides using solid-phase synthesis by annealing in air in the temperature range of 1223-1273 K. Its crystal structure was determined (space group Cm). The influence of temperature on high-temperature heat capacity of the synthesized germanate was studied by the differential scanning calorimetry method. It was found that the dependence of heat capacity on temperature has an extreme value related to a phase transition. The thermodynamic properties were calculated based on the experimental data about heat capacity.
Смотреть статью,
Читать в сети ИФ
Найти похожие

12.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Aleksandrovsky A.S., Arkhipkin V.G., Bezmaternykh L.N., Gudim I.A., Krylov A.S., Vagizov F.
Заглавие : Optical and Mossbauer Spectroscopy of Europium Gallium Garnet Single Crystals Grown from Fluxes of Different Content
Место публикации : Известия высших учебных заведений. Физика. - 2008. - Т. 51, № 10/2. - С. 110-114
Найти похожие

13.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Denisova L. T., Molokeev M. S., Aleksandrovskii A. S., Kargin Y. F., Golubeva E. O., Denisov V. M.
Заглавие : Crystal structure, luminescence, and thermodynamic properties of Pb10–xEux(GeO4)2+x(VO4)4–x (x = 0.1, 0.2, 0.3) substituted apatites
Место публикации : Inorg. Mater. - 2021. - Vol. 57, Is. 11. - P.1158-1166. - ISSN 00201685 (ISSN), DOI 10.1134/S0020168521110030
Примечания : Cited References: 26. - This work was supported in part by the Russian Federation Ministry of Science and Higher Education as part of the state research target for the Siberian Federal University federal state autonomous educational institution of higher education, project no. FSRZ-2020-0013
Аннотация: Pb10 – xEux(GeO4)2 + x(VO4)4 – x (x = 0.1, 0.2, 0.3) Eu-substituted lead germanatovanadates with the apatite structure have been prepared by solid-state reactions, via firing in air in the temperature range 773–1073 K, using oxides (PbO, Eu2O3, GeO2, and V2O5) as starting materials. Using X-ray diffraction, we have determined the hexagonal cell parameters (sp. gr. P63/m) of the synthesized phases and refined their crystal structure (the atomic position coordinates, isotropic thermal parameters, and principal bond lengths in their structure are presented). We have measured the luminescence spectra of the Pb10 – xEux(GeO4)2 + x(VO4)4 – x (x = 0.1, 0.2, 0.3) apatites and shown that europium concentration has little effect on the shape of the luminescence spectra. Using experimental heat capacity data obtained for polycrystalline samples by differential scanning calorimetry in the temperature range 350–1050 K, we calculated the main thermodynamic functions of the Eu-substituted lead germanatovanadates.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие

14.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Denisenko Y. G., Sedykh A. E., Molokeev M. S., Oreshonkov A. S., Aleksandrovsky A. S., Krylov A. S., Khritokhin N. A., Sal'nikova E. I., Andreev O. V., Muller-Buschbaum K.
Заглавие : Crystal and electronic structure, thermochemical and photophysical properties of europium-silver sulfate monohydrate AgEu(SO4)2·H2O
Место публикации : J. Solid State Chem. - 2021. - Vol. 294. - Ст.121898. - ISSN 00224596 (ISSN), DOI 10.1016/j.jssc.2020.121898
Примечания : Cited References: 54. - This work was partially supported by the Russian Foundation for Basic Research (Grant 19-33-90258∖19 ). Use of equipment of Krasnoyarsk Regional Center of Research Equipment of Federal Research Center « Krasnoyarsk Science Center SB RAS» is acknowledged
Аннотация: In order to synthesize single crystals of europium-silver double sulfate monohydrate, a hydrothermal reaction route was used. It was found that the crystallization cannot be performed under standard conditions. The compound AgEu(SO4)2·H2O crystallizes in the trigonal crystal system, space group P3221 (a = 6.917(1), c = 12.996(2) Å, V = 538.53(17) Å3). The structure consists of triple-capped trigonal prisms [EuO9], in which one oxygen atom belongs to crystalline water, silver octahedra [AgO6], and sulfate tetrahedra [SO4]. The hydrogen bonds in the system additionally stabilize the structure. The electronic band structure wasstudied by density functional theory calculations which show that AgEu(SO4)2·H2O is an indirect band gap dielectric. Temperature dependent photoluminescence spectroscopy shows emission bands of transitions from the 5D0 state to the spin-orbit components of the 7FJmultiplet (J = 0–6).The ultranarrow transition 5D0 - 7F0 shows a red shift with respect to other europium-containing water-free sulfates that is ascribed to the presence of OH group in the crystal structure in the close vicinity of the Eu3+ ion. An effect of abnormal sensitivity of the Ω4 intensity factor to minor distortions of the local environment is detected for the observed low local symmetry of C2.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие

15.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Denisenko Y. G., Sedykh A. E., Oreshonkov A. S., Molokeev M. S., Azarapin N. O., Sal'nikova E. I., Chimitova O. D., Andreev O. V., Razumkova I. A., Muller-Buschbaum K.
Заглавие : Europium (II) sulfate EuSO4: Synthesis methods, crystal and electronic structure, luminescence properties
Коллективы : [0273-2021-0008]
Место публикации : Eur. J. Inorg. Chem. - 2022. - Vol. 2022, Is. 12. - Ст.e202200043. - ISSN 1434-1948, DOI 10.1002/ejic.202200043. - ISSN 1099-0682(eISSN)
Примечания : Cited References: 69. - This research is partially supported by the state order of BINM SB RAS (project no. 0273-2021-0008)
Предметные рубрики: DEPENDENT DECAY BEHAVIOR
ELECTROCHEMICAL REDUCTION
OPTICAL-PROPERTIES
Аннотация: In the present work, we report on the synthesis of EuSO4 powders by two different methods using EuS as starting material. The compound EuSO4 contains divalent europium and crystallizes in the orthorhombic crystal system, space group Pnma with parameters close to SrSO4. The compound exhibits near isotropic thermal expansion over the temperature range 300–700 K. EuSO4 was examined by Raman, Fourier-transform infrared absorption and luminescence spectroscopy methods. EuSO4 is found to be an indirect bandgap material with a bandgap close to direct electronic transition. The emission lifetime of divalent europium d-f emission in EuSO4 shows an unusual behavior for stoichiometric compounds, as it shortens upon cooling from 1.11(1) μs at room temperature to 0.44(1) μs at 77 K.
Смотреть статью,
Scopus,
WOS
Найти похожие

16.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Yang, Zhiyu, Liu, Gaochao, Zhao, Yifei, Zhou, Yayun, Qiao, Jianwei, Molokeev M. S., Swart, Hendrik C., Xia, Zhiguo
Заглавие : Competitive site occupation toward improved quantum efficiency of SrLaScO4:Eu red phosphors for warm white LEDs
Коллективы : International Cooperation Project of National Key Research and Development Program of China [2021YFE0105700]; National Natural Science Foundation of ChinaNational Natural Science Foundation of China (NSFC) [51972118, 51961145101]; Guangzhou Science & Technology Project [202007020005]; State Key Laboratory of Luminescent Materials and Devices [Skllmd-2021-09]; China Postdoctoral Science FoundationChina Postdoctoral Science Foundation [2021M691053]; Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program [2017BT01X137]; RFBRRussian Foundation for Basic Research (RFBR) [19-52-80003]; NRF International: SA/China Joint Research Programme 2021 [CHIN2002265 06921 UID 132785]
Место публикации : Adv. Opt. Mater. - 2022. - Vol. 10. Is. 6. - Ст.2102373. - ISSN 2195-1071, DOI 10.1002/adom.202102373
Примечания : Cited References: 42. - This research was supported by the International Cooperation Project of National Key Research and Development Program of China (Program No. 2021YFE0105700), National Natural Science Foundation of China (Grant Nos. 51972118 and 51961145101), Guangzhou Science & Technology Project (Project No. 202007020005), the State Key Laboratory of Luminescent Materials and Devices (Grant No. Skllmd-2021-09), China Postdoctoral Science Foundation (Grant No. 2021M691053), and the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program (Program No. 2017BT01X137). This work was also funded by RFBR according to the research Project No. 19-52-80003 and the NRF International: SA/China Joint Research Programme 2021 - CHIN2002265 06921 UID 132785
Предметные рубрики: LUMINESCENCE
EUROPIUM
BLUE
EU2+
STABILIZATION
EPR
Аннотация: The discovery of Eu2+-doped high-efficiency red phosphors remains a vital challenge for white light-emitting diode (WLED) applications. It is therefore urgent to find effective strategies managing the oxidation state to help reduce Eu3+ to Eu2+ and accordingly increase the photoluminescence quantum yield (PLQY). Herein, a new red-emitting SrLaScO4:Eu phosphor is designed, and the PLQY is enhanced from 13% to 67% under 450 nm excitation by employing (NH4)2SO4-assisted sintering. Combined structural analysis, optical spectroscopy, and theoretical calculation reveal that predominant Eu2+ prefers to occupy the Sr2+ sites in the SrLaScO4 enabling red emission, and a competitive site occupation of Eu3+ in La3+ can be restrained, and the reduction mechanism of Eu3+ to Eu2+ originating from the (NH4)2SO4 addition is analyzed. The fabricated WLED device using red-emitting SrLaScO4:Eu and yellow-emitting Y3(Al,Ga)5O12:Ce3+ exhibits a high color-rendering index of 86.7 at a low correlated color temperature of 4005 K. This work provides a feasible reduction strategy for guiding the development of high-efficiency Eu2+-doped red phosphor for WLED applications.
Смотреть статью,
Scopus,
WOS
Найти похожие

17.

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.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие

18.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Ji H. P., Huang Z. H., Xia Z. G., Molokeev M. S., Atuchin V. V., Fang M. H., Huang S. F.
Заглавие : New yellow-emitting whitlockite-type structure Sr1.75Ca 1.25(PO4)2:Eu2+ phosphor for near-UV pumped white light-emitting devices
Место публикации : Inorg. Chem.: American Chemical Society, 2014. - Vol. 53, Is. 10. - P.5129-5135. - ISSN 0020-1669, DOI 10.1021/ic500230v. - ISSN 1520-510X
Примечания : Cited References: 31. - This work was supported by the National Natural Science Foundations of China (Grant Nos. 51032007, 51002146, 51272242), the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20130022110006), and the Program for New Century Excellent Talents in University of Ministry of Education of China (NCET-12-0950). V.V.A. gratefully acknowledges the Ministry of Education and Science of the Russian Federation for the financial support. S.H. would like to acknowledge the China Scholarship Council (CSC) for providing a doctoral scholarship for his Ph.D. study at the University of Auckland.
Предметные рубрики: LUMINESCENCE PROPERTIES
CRYSTAL-STRUCTURE
RED PHOSPHOR
DIODES
LEDS
SR
CA
ORTHOPHOSPHATE
CA-3(PO4)2
EUROPIUM
Аннотация: New compound discovery is of interest in the field of inorganic solid-state chemistry. In this work, a whitlockite-type structure Sr1.75Ca1.25(PO4)2 newly found by composition design in the Sr3(PO4)2–Ca3(PO4)2 join was reported. Crystal structure and luminescence properties of Sr1.75Ca1.25(PO4)2:Eu2+ were investigated, and the yellow-emitting phosphor was further employed in fabricating near-ultraviolet-pumped white light-emitting diodes (w-LEDs). The structure and crystallographic site occupancy of Eu2+ in the host were identified via X-ray powder diffraction refinement using Rietveld method. The Sr1.75Ca1.25(PO4)2:Eu2+ phosphors absorb in the UV–vis spectral region of 250–430 nm and exhibit an intense asymmetric broadband emission peaking at 518 nm under λex = 365 nm which is ascribed to the 5d–4f allowed transition of Eu2+. The luminescence properties and mechanism are also investigated as a function of Eu2+ concentration. A white LED device which is obtained by combining a 370 nm UV chip with commercial blue phosphor and the present yellow phosphor has been fabricated and exhibit good application properties.
Смотреть статью,
Scopus,
WoS,
Читать в сети ИФ
Найти похожие

19.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Atuchin V. V., Aleksandrovsky A. S., Chimitova O. D., Gavrilova T. A., Krylov A. S., Molokeev M. S., Oreshonkov A. S., Bazarov B. G., Bazarova J. G.
Заглавие : Synthesis and spectroscopic properties of monoclinic α-Eu2(MoO4)3
Коллективы : Ministry of Education and Science of the Russian Federation
Место публикации : J. Phys. Chem. C: American Chemical Society, 2014. - Vol. 118, Is. 28. - P.15404-15411. - ISSN 1932-7447, DOI 10.1021/jp5040739
Примечания : Cited References: 63. - This study is partly supported by the Ministry of Education and Science of the Russian Federation.
Предметные рубрики: RARE-EARTH MOLYBDATES
VIBRATIONAL PROPERTIES
LUMINESCENCE PROPERTIES
CRYSTAL-STRUCTURE
PHASE-TRANSITIONS
TRIPLE MOLYBDATE
SINGLE-CRYSTAL
X-RAY
PHOSPHORS
EUROPIUM
Аннотация: The microcrystals of monoclinic europium molybdate, alpha-Eu-2(MoO4)(3), have been fabricated by solid-state synthesis at T = 753-1273 K for 300 h. The crystal structure of alpha-Eu-2(MoO4)(3) has been refined by the Rietveld method and was found to belong to the space group C2/c with unit cell parameters a = 7.5576(1), b = 11.4709(2), c = 11.5158(2) angstrom, and beta = 109.278(1)degrees (R-B = 3.39%). About 40 narrow Raman lines have been observed in the Raman spectrum of the alpha-Eu-2(MoO4)(3) powder sample. The luminescence spectra of alpha-Eu-2(MoO4)(3) under excitation at 355 and 457.9 nm reveal domination of induced electric dipole transition D-5(0) - F-7(2) and the presence of ultranarrow lines at D-5(0) - F-7(0) and D-5(1) - F-7(0) transitions.
Смотреть статью,
Scopus,
WoS,
Читать в сети ИФ
Найти похожие

20.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Kuz'menko A. M., Mukhin A. A., Ivanov V. Y., Kadomtseva A. M., Lebedev S. P., Bezmaternykh L. N.
Заглавие : Antiferromagnetic Resonance and Dielectric Properties of Rare-earth Ferroborates in the Submillimeter Frequency Range
Место публикации : J. Exp. Theor. Phys.: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2011. - Vol. 113, Is. 1. - P113-120. - ISSN 1063-7761, DOI 10.1134/S106377611105013X
Примечания : Cited References: 27. - This work was supported by the Russian Foundation for Basic Research, project no. 10-02-00846.
Предметные рубрики: GDFE3(BO3)(4)
SPECTROSCOPY
CRYSTAL
Ключевые слова (''Своб.индексиров.''): antiferromagnetic resonance--basic parameters--effective anisotropy constant--ferroborates--ferroics--ferromagnetic orderings--frequency ranges--magnetic interactions--magnetoresonance--millimeter frequency range--rare earth ions--submillimeters--antiferromagnetic materials--crystallography--erbium--europium--ferromagnetic resonance--ion exchange--magnetic anisotropy--magnetic devices--magnetic structure--permittivity--resonance--antiferromagnetism
Аннотация: The magnetoresonance and dielectric properties of a number of crystals of a new family of multiferroics, namely, rare-earth ferroborates RFe(3)(BO(3))(4) (R = Y, Eu, Pr, Tb, Tb(0.25)Er(0.75)), are studied in the submillimeter frequency range (nu = 3-20 cm(-1)). Ferroborates with R = Y, Tb, and Eu exhibit permittivity jumps at temperatures of 375, 198, and 58 K, respectively, which are caused by the R32 - P3(1)2(1) phase transition. Antiferromagnetic resonance (AFMR) modes in the subsystem of Fe(3+) ions are detected in the range of antiferromagnetic ordering (T T(N)
WOS,
Scopus,
Читать в сети ИФ
Найти похожие