Библиотека института физики им. Л.В. Киренского СО РАН

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Вид документа : Статья из сборника (однотомник)
Шифр издания :
Автор(ы) : Antonova A.B., Chudin O.S., Rubaylo A.I., Pavlenko N.I., Sokolenko W.A., Verpekin V.V., Vasiliev A.D., Semeikin O.V.
Заглавие : Heteronuclear µ-vinylidene complexes containing Re, Cu, Fe, Pt, Pd. Synthesis, structure, IR and NMR spectra
Коллективы : Carbene Chemistry Conference The Ocean Maya
Место публикации : Carbene Chemistry Conference The Ocean Maya. - P.38
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Вид документа : Статья из журнала
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Автор(ы) : Malakhovskii A. V., Sokolov V. V., Karimov D.N.
Заглавие : Nature of magnetic circular dichroism and absorption spectra of f-f transitions in Na0.4Ho0.6F2.2 single crystal
Колич.характеристики :5 с
Место публикации : Chem. Phys. - 2024. - Vol. 581. - Ст.112257. - ISSN 03010104 (ISSN), DOI 10.1016/j.chemphys.2024.112257. - ISSN 18734421 (eISSN)
Примечания : Cited References: 25
Аннотация: We present first study of magnetic circular dichroism (MCD) spectra of Ho3+ ion in C4v local symmetry, which it has in fluorite Na0.4Ho0.6F2.2. Optical absorption and MCD spectra were studied in this single crystal in the region of 5I8 5F3, 5F2, 3K8 and 5G5 transitions in the temperature range 3.6–––90 K. It was revealed, that number of transitions observed in the MCD and absorption spectra coincides with the number of transitions only from the doublet E state to singlet excited states. The E-E type transitions are not active in MCD, but they are not observed in the absorption spectra either. Paramagnetic magneto-optical activities (MOA) of the absorption bands and their temperature dependences were measured and interpreted with the help of the theory based on the nature of f-f transitions allowance. The MCD spectra were also analyzed in approximation of the J,±MJ wave functions of the free atom. It was shown in particular, that the lowest initial state of the transitions observed at T ˃ 10 K had MJ = 7, but this is not the lowest state of the holmium ion in the crystal. A little lower there is a quasi-doublet with MJ = 8 and, accordingly, with a higher magneto-optical activity of transitions from it. However, the intensity of transitions from this state is low.
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Вид документа : Статья из журнала
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Автор(ы) : Begunovich L. V., Kovaleva E. A., Korshunov M. M., Shabanov V. F.
Заглавие : Absorption spectra of the purple nonsulfur bacteria light-harvesting complex: A DFT study of the B800 part
Колич.характеристики :7 с
Место публикации : J. Photochem. Photobiol. A: Chem. - 2024. - Vol. 450. - Ст.115454. - ISSN 10106030 (ISSN), DOI 10.1016/j.jphotochem.2023.115454. - ISSN 18732666 (eISSN)
Примечания : Cited References: 42. - This work was supported by the state assignment of the Ministry of Science and Higher Education of the Russian Federation. Authors would like to thank Information Technology Centre, Novosibirsk State University for providing access to their supercomputers. L.V.B. would like to thank Irkutsk Supercomputer Center of SB RAS for providing the access to HPC-cluster «Akademik V.M. Matrosov» (Irkutsk Supercomputer Center of SB RAS, Irkutsk: ISDCT SB RAS; http://hpc.icc.ru, accessed 20.10.2023)
Аннотация: We’ve studied the B800 part of Rhodoblastus acidophilus light-harvesting complex (LH2) by several quantum chemical techniques based on the density functional theory (DFT) and determined the specific method and a minimal reliable model suitable for further studies of the LH2. In addition to bacteriochlorophyll a molecules, the minimal model includes two α and one β chain amino acids. Within the model, we are able to reproduce the contribution of the B800 ring of nine bacteriochlorophyll a molecules to the near infrared Qy absorption band. We also discuss the use of hybrid DFT calculations for precise energy and optical estimations and DFT-based tight binding (DFTB) method for the large-scale calculations. Crucial importance of Hartree-Fock exchange interaction for the correct description of B800 peak position was shown.
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Вид документа : Статья из журнала
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Автор(ы) : Vnukova N. G., Nikolaev N. S., Bartseva L. S., Kastiuk M. R., Elesina V. I., Isakova V. G., Churilov G. N.
Заглавие : Enrichment of a fullerene mixture with endohedral metallofullerenes: methodology and evaluation
Колич.характеристики :5 с
Место публикации : Fuller. Nanotub. Carbon Nanostructures. - 2024. - Article in press. - ISSN 1536383X (ISSN), DOI 10.1080/1536383X.2024.2338524. - ISSN 15364046 (eISSN)
Примечания : Cited References: 46
Аннотация: A fullerene mixture was enriched with endohedral metallofullerenes (EMF) using Lewis acid (TiCl4), which took 22 min, whereas the standard method requires about 8 h. An algorithm for assessing small-area chromatographic peaks has been proposed, which has improved the accuracy of determination. For example, the area of the C84 peak was 4.24% using the developed program, while the use of chromatograph software estimated the area of this peak to be 1.78%.
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Вид документа : Статья из журнала
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Автор(ы) : Каравайский, Андрей Юрьевич, Лукин, Юрий Иванович
Заглавие : Влияние органического вещества и влажности на пересечение спектров диэлектрической проницаемости почв
Колич.характеристики :21 с
Место публикации : Журн. радиоэлектрон. - 2024. - № 4. - Ст.4. - ISSN 16841719 (eISSN), DOI 10.30898/1684-1719.2024.4.11; J. Radio Electron.
Примечания : Библиогр.: 31. - Работа выполнена при финансовой поддержке Российского научного фонда и Красноярского краевого фонда поддержки научной и научно-технической деятельности в рамках научного проекта № 22-27-20112
Аннотация: Проведено исследование пересечений спектров вещественной части комплексной диэлектрической проницаемости влажных органических почв с различным содержанием органического вещества от 11 до 54 % в диапазоне частот от 15 МГц до 15 ГГц и в диапазоне температур от 0 до 25 °С. На основании полученных экспериментальных зависимостей предложена эмпирическая модель для оценки среднего значения частот, на которых наблюдается пересечения спектров диэлектрической проницаемости почв, в диапазоне изменений значений этих частот при изменении температуры. Предложенная модель также включает формулу расчета значения объемной влажности, при которой появляется пересечение спектров диэлектрической проницаемости почв.The present study considers the crossover of the real part spectra of the complex dielectric constant obtained in the frequency range from 15 MHz to 15 GHz and temperature range from 0 to 25 °C for moist organic soils with the content of organic matter varying from 11 to 54 %. Based on the obtained experimental dependences, the empirical model is proposed to estimate the average value of the frequencies at which the crossover point of the soil dielectric constant spectra are observed with temperature changes. The proposed model also includes a formula for calculating the value of volumetric moisture at which the crossover point of the soil dielectric constant spectra appears.
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Вид документа : Статья из журнала
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Автор(ы) : Golovkina E. V., Krylova S. N., Vtyurin A. N., Krylov A. S.
Заглавие : Analyzing the symmetry of the Raman spectra of crystals according to angular dependences
Колич.характеристики :6 с
Место публикации : Bull. Russ. Acad. Sci. Phys. - 2024. - Vol. 88, Is. 5. - P.773-778. - ISSN 10628738 (ISSN), DOI 10.1134/S1062873824706573. - ISSN 19349432 (eISSN)
Примечания : Cited References: 32. - This work was supported by the Russian Foundation for Basic Research, project no. 21-52-12018. The authors are grateful to Dr. Irena Senkovska for providing our DUT-8(Ni) samples
Аннотация: The authors propose a way of reconstructing the Raman tensor by studying the angular dependences of the intensities of the Raman lines of unoriented microcrystals. The technique is verified using familiar calomel Hg2Cl2 crystals. It is shown that the lines on DUT-8 (Ni) crystals indicating phases with open and closed pores have different types of symmetries. The technique can be used to reconstruct the Raman tensor for any unoriented crystalline sample.
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Вид документа : Статья из сборника (однотомник)
Шифр издания :
Автор(ы) : Nikiforov A. A., Krylov A. S., Pelegov D. V.
Заглавие : Raman spectra interpretation for Li4Ti5O12 with a spinel structure
Коллективы : Уральский Федеральный университет им. Первого Президента России Б.Н. Ельцина, Ural Federal University, "Materials science and nanotechnology", International conference
Место публикации : Materials Science and Nanotechnology (MSN-2023): abstract book of International conference/ Ural Federal University; org. com. A. N. Vtyurin et al. - Ekaterinburg, 2023. - Ст.P26. - P.110. - ISBN 978-5-9500624-6-9
Примечания : Russian Science Foundation (No 22-22-00350
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Tomilin F. N., Artyushenko P. V., Shchugoreva I. A., Rogova A. V., Vnukova N. G., Churilov G. N., Shestakov N. P., Tchaikovskaya O. N., Ovchinnikov S. G., Avramov P. V.
Заглавие : Structure and vibrational spectroscopy of C82 fullerenol valent isomers: An experimental and theoretical joint study
Место публикации : Molecules. - 2023. - Vol. 28, Is. 4. - Ст.1569. - ISSN 14203049 (eISSN), DOI 10.3390/molecules28041569
Примечания : Cited References: 57. - Synthesis and spectroscopic study of the Gd@C82OxHy complexes were supported by the Ministry of Science and Higher Education of the Russian Federation under project FWES-2022-0005. Molecular design of the fullerene derivatives was supported by the National Research Foundation of the Republic of Korea, grant NRF 2021R1A2C1010455. DFTB3 electronic structure calculations were supported by Project FSWM-2020-0033 of the Russian Ministry of Science and Education
Аннотация: Gd@C82OxHy endohedral complexes for advanced biomedical applications (computer tomography, cancer treatment, etc.) were synthesized using high-frequency arc plasma discharge through a mixture of graphite and Gd2O3 oxide. The Gd@C82 endohedral complex was isolated by high-efficiency liquid chromatography and consequently oxidized with the formation of a family of Gd endohedral fullerenols with gross formula Gd@C82O8(OH)20. Fourier-transformed infrared (FTIR) spectroscopy was used to study the structure and spectroscopic properties of the complexes in combination with the DFTB3 electronic structure calculations and infrared spectra simulations. It was shown that the main IR spectral features are formed by a fullerenole C82 cage that allows one to consider the force constants at the DFTB3 level of theory without consideration of gadolinium endohedral ions inside the carbon cage. Based on the comparison of experimental FTIR and theoretical DFTB3 IR spectra, it was found that oxidation of the C82 cage causes the formation of Gd@C82O28H20, with a breakdown of the integrity of the parent C82 cage with the formation of pores between neighboring carbonyl and carboxyl groups. The Gd@C82O6(OOH)2(OH)18 endohedral complex with epoxy, carbonyl and carboxyl groups was considered the most reliable fullerenole structural model.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Smirnov, Mikhail, Roginskii, Evgenii, Savin, Aleksandr, Oreshonkov A. S., Pankin, Dmitrii
Заглавие : Density-functional study of the Si/SiO2 interfaces in short-period superlattices: Vibrational states and Raman spectra
Колич.характеристики :18 с
Место публикации : Photonics. - 2023. - Vol. 10, Is. 8. - Ст.902. - ISSN 23046732 (eISSN), DOI 10.3390/photonics10080902
Примечания : Cited References: 61. - The study was supported by grants from the Russian Science Foundation (project No. 22-22-20021) and the Saint-Petersburg Science Center (project No. 32/2022), using the resources of the Computing Center and the Center for Optical and Laser Materials Research at the Research Park of St. Petersburg State UniversityThe study was performed using the resources of the Computing Center and the Center for Optical and Laser Materials Research at the Research Park of St. Petersburg State University. The authors thank Konstantin Smirnov for his valuable advice. The calculations were also performed in part using the facilities of the JSCC supercomputer center at RAS and the Konstantinov computational center at the Ioffe Institute
Аннотация: Raman spectroscopy has proven its effectiveness as a highly informative and sensitive method for the nondestructive analysis of layered nanostructures and their interfaces. However, there is a lack of information concerning the characteristic phonon modes and their activity in Si/SiO2 nanostructures. In order to overcome this problem, the phonon states and Raman spectra of several Si/SiO2 superlattices (SL) with layer thicknesses varied within 0.5–2 nm are studied using DFT-based computer modeling. Two types of structures with different interfaces between crystalline silicon and SiO2 cristobalite were studied. A relationship between the phonon states of heterosystems and the phonon modes of the initial crystals was established. Estimates of the parameters of deformation potentials are obtained, with the help of which the shifts of phonon frequencies caused by elastic strains in the materials of the SL layers are interpreted. The dependence of intense Raman lines on the SL structure has been studied. Several ways have been proposed to use this information, both for identifying the type of interface and for estimating the structural parameters. The obtained information will be useful for the spectroscopic characterization of the silicon/oxide interfaces.
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10.

Вид документа : Статья из журнала
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Автор(ы) : Gan’shina, Elena A., Granovsky, Alexandr B., Garshin, Vladimir V., Pripechenkov, Ilya M., Sitnikov, Alexandr V., Volochaev M. N., Ryl’kov, Vladimir V., Nikolaev, Sergey N.
Заглавие : Magneto-optical spectroscopy of nanocomposites (CoFeZr)x(Al2O3)100-x
Место публикации : SPIN. - 2023. - Vol. 13, Is. 1. - Ст.2340006. - ISSN 20103247 (ISSN), DOI 10.1142/S2010324723400064. - ISSN 20103255 (eISSN)
Примечания : Cited References: 17. - This work was supported in part by the Russian Foundation for Basic Research under Grant 22-29-00392. Magnetic and MO studies were performed using equipment purchased at the expense of the MSU The authors thank the Krasnoyarsk Regional Center of Research Equipment of Federal Research Center “Krasnoyarsk Science Center SB RAS” for assistance
Аннотация: We present results of magneto-optical investigations of (CoFeZr)x(Al2O3)100-x film nanocomposites in transverse Kerr effect (TKE) geometry in the spectral range 0.5-4.0eV and magnetic field up to 3.0kOe. Nanocomposites were deposited onto a glass-ceramic substrate by ion-beam sputtering. The TKE response at room temperature strongly depends on the wavelength of light, applied magnetic field H and the volume metallic fraction. From the analysis of the field dependences of TKE at different wavelengths, it follows that in the as-deposited samples, the interaction between nanoparticles at x30at.% is small and the nanocomposite is an ensemble of superparamagnetic particles; as x increases to 32at.%, a superspinglass-type state arises, then, in the vicinity of 34at.%, along with individual superparamagnetic particles, superferromagnetic regions appear. Long-range ferromagnetic order arises at concentrations x less than the percolation threshold for conductivity xper
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11.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Tarasov A. S., Lyashchenko S. A., Rautskii M. V., Lukyanenko A. V., Andryushchenko T. A., Solovyov, Leonid A., Yakovlev I. A., Maximova O. A., Shevtsov D. V., Bondarev M. A., Bondarev I. A., Ovchinnikov S. G., Varnakov S. N.
Заглавие : Growth process, structure and electronic properties of Cr2GeC and Cr2-xMnxGeC thin films prepared by magnetron sputtering
Колич.характеристики :12 с
Место публикации : Processes. - 2023. - Vol. 11, Is. 8. - Ст.2236. - ISSN 22279717 (eISSN), DOI 10.3390/pr11082236
Примечания : Cited References: 43. - This study was supported by the Russian Science Foundation, project no. 21-12-00226The authors thank the laboratory of the Magnetic MAX Materials created under the Megagrant project (agreement no. 075-15-2019-1886) for providing experimental equipment and the Collective Use Center at the Krasnoyarsk Scientific Center (Siberian Division, Russian Academy of Sciences) for assistance
Аннотация: The growth and phase formation features, along with the influence of structure and morphology on the electronic, optical, and transport properties of Cr2GeC and Cr2-xMnxGeC MAX phase thin films synthesized by magnetron sputtering technique, were studied. It was found that the Cr:Ge:C atomic ratios most likely play the main role in the formation of a thin film of the MAX phase. A slight excess of carbon and manganese doping significantly improved the phase composition of the films. Cr2GeC films with a thicknesses exceeding 40 nm consisted of crystallites with well-developed facets, exhibiting metallic optical and transport properties. The hopping conduction observed in the Cr2-xMnxGeC film could be attributed to the columnar form of crystallites. Calculations based on a two-band model indicated high carrier concentrations N, P and mobility μ in the best-synthesized Cr2GeC film, suggesting transport properties close to single crystal material. The findings of this study can be utilized to enhance the growth technology of MAX phase thin films.
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12.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Moshkina E. M., Eremin E. V., Molokeev M. S., Kokh, Dieter, Krylov A. S.
Заглавие : Flux growth and Raman spectroscopy study of Cu2CrBO5 crystals
Колич.характеристики :15 с
Место публикации : Crystals. - 2023. - Vol. 13, Is. 10. - Ст.1415. - ISSN 20734352 (eISSN), DOI 10.3390/cryst13101415
Примечания : Cited References: 24. - The study was supported by a grant from the Russian Science Foundation and the Krasnoyarsk Regional Science Foundation No. 22-12-20019; https://rscf.ru/project/22-12-20019/
Аннотация: Multicomponent flux systems based on both Li2WO4-B2O3-Li2O-CuO-Cr2O3 and Bi2O3-MoO3-B2O3-Na2O-CuO-Cr2O3 were studied in order to grow Cu2CrBO5 crystals. The conditions for Cu2CrBO5 crystallization were investigated by varyingthe component ratios, and the peculiarities of their interaction were characterized by studying the formation sequence of high-temperature crystallizing phases. Special attention was paid to the problem of Cr2O3 solubility. Phase boundaries between CuCrO2, Cu2CrO4, and Cu2CrBO5 were considered. The crystal structure of the obtained samples was studied viasingle crystal and powder X-ray diffraction. The chemical composition of the grown crystals was examined using the EDX technique. Anactual ratio of Cu:Cr = 1.89:1.11 was found for Cu2CrBO5 grown from the lithium-tungstate system, which showed a small deviation from 2:1, implying the presence of a part of bivalent Cr2+ in the samples. Anomalies in the thermal dependence of magnetization were analyzed and compared with the previously obtained data for Cu2CrBO5. The anomaly at TC ≈ 42 K and the antiferromagnetic phase transition at TN ≈ 119 K were considered. Polarized Raman spectra of Cu2CrBO5 were obtained for the first time, and a comparative analysis of the obtained data with other monoclinic and orthorhombic ludwigites is presented. Along with the polarized room temperature spectra, the thermal evolution of Raman modes near the antiferromagnetic phase transition temperature TN ≈ 119 K is provided. The influence of the magnetic phase transition on the Raman spectra of Cu2CrBO5 is discussed.
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13.

Вид документа : Статья из сборника (выпуск продолж. издания)
Шифр издания :
Автор(ы) : Karavayskiy A. Yu., Lukin Y. I.
Заглавие : The effect of clay content on the spectra of permetivity of mineral soils at positive temperatures
Колич.характеристики :4 с
Коллективы : Radiation and Scattering of Electromagnetic Waves 2023
Место публикации : Conf. Proc. - Radiat. Scatt. Electromagn. Waves, RSEMW. - 2023. - P.456-459. - , DOI 10.1109/RSEMW58451.2023.10201998
Примечания : Cited References: 17. - The work was financially supported by the Russian Science Foundation and the Krasnoyarsk Regional Fund for Support of Scientific and Scientific and Technical Activities within the framework of the scientific project No. 22-27-20112
Аннотация: In this research, it was studied the crossover frequencies of the spectra of the real part of the permittivity of moist mineral soils with different clay content from 10 to 64% in the frequency range from 15 MHz to 15 GHz and in the temperature range from 25 to 0 °C. Based on the experimental dependences obtained, empirical models were proposed for the average crossover frequency of the soil of the real part of the permittivity spectra in the range of changes of these frequencies values with temperature changes, as well as for the half-widths of the ranges of changes.
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14.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Ryabin A. A., Krylov A. S., Krylova S. N., Kiselev E. A., Pelegov D. V.
Заглавие : Thermal evolution of LiCoO2 structure and Raman spectra below 400 °C
Колич.характеристики :9 с
Место публикации : J. Chem. Phys. - 2023. - Vol. 159, Is. 8. - Ст.084706. - ISSN 00219606 (ISSN), DOI 10.1063/5.0164135. - ISSN 10897690 (eISSN)
Примечания : Cited References: 60. - The research was funded by the Russian Science Foundation (Project No. 22-22-00350, https://rscf.ru/project/22-22-00350). The Raman spectra measurements were made using equipment of the Ural Center for Shared Use “Modern nanotechnology” Ural Federal University (Reg. No. 2968), supported by the Ministry of Science and Higher Education of the Russian Federation (Project No. 075-15-2021-677). Authors warmly thank Professor Jongwoo Lim (Seoul National University) for samples, reading the manuscript, and providing his valuable comments
Аннотация: Lithium cobalt oxide is a convenient model material for the vast family of cathode materials with a layered structure and still retains some commercial perspectives for microbatteries and some other applications. In this work, we have used ab initio calculations, x-ray diffraction, Raman spectroscopy, and a theoretical physical model, based on quasi-harmonic approximation with anharmonic contributions of the three-phonon and four-phonon processes, to study a temperature-induced change of Raman spectra for LiCoO2. The obtained values of shift and broadening for Eg and A1g bands can be used for quantitative characterization of temperature change, for example, due to laser-induced heating during Raman spectra measurements. The theoretical analysis of the experimental results lets us conclude that Raman spectra changes for LiCoO2 can be explained by the combination of thermal expansion of the crystal lattice and phonon damping by anharmonic coupling with comparable contributions of the three-phonon and four-phonon processes. The obtained results can be further used to develop Raman-based quality control tools.
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15.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Balaev D. A., Stolyar S. V., Knyazev Yu. V., Yaroslavtsev R. N., Pankrats A. I., Vorotynov A. M., Krasikov A. A., Velikanov D. A., Bayukov O. A., Ladygina V. P., Iskhakov R. S.
Заглавие : Role of the surface effects and interparticle magnetic interactions in the temperature evolution of magnetic resonance spectra of ferrihydrite nanoparticle ensembles
Место публикации : Results Phys. - 2022. - Vol. 35. - Ст.105340. - ISSN 22113797 (ISSN), DOI 10.1016/j.rinp.2022.105340
Примечания : Cited References: 119. - Authors thank to A.D. Balaev, S.V. Komogortsev for fruitful discussions and M.N. Volochaev for TEM studies. The TEM study and measurements of X-band FMR spectra were carried out on the equipment of the Krasnoyarsk Territorial Center for Collective Use, Krasnoyarsk Scientific Center, Siberian Branch, Russian Academy of Sciences. This study was supported by the Russian Science Foundation, project no. 21-72-00025 (https://rscf.ru/project/21-72-00025/) "Tuning the Magnetic Properties of Ultrafine Biocompatible Ferrihydrite Nanoparticles through Interparticle Interactions"
Аннотация: Ferrihydrite is characterized by the antiferromagnetic ordering and, in ferrihydrite nanoparticles, as in nanoparticles of any antiferromagnetic material, an uncompensated magnetic moment is formed. We report on the investigations of ferrihydrite powder systems with an average particle size of ∼ 2.5 nm obtained (i) as a product of the vital activity of bacteria (sample FH-bact) and (ii) by a chemical method (sample FH-chem). In the first approximation, these samples can be considered to be identical. However, in sample FH-chem, particles contact directly, while in sample FH-bact, they have organic shells; therefore, the interparticle magnetic interactions in these samples have different degrees. The main goal of this work has been to establish the effects of the interparticle magnetic interactions and individual characteristics of ferrihydrite nanoparticles on ferromagnetic resonance (FMR) spectra. The FMR spectra have been measured at different (9.4–75 GHz) frequencies in a wide temperature range. It has been found that, at low temperatures, the field-frequency dependence ν(HR) of the investigated systems has a gap ν/γ = HR + HA, where HR is the resonance field and HA is the induced anisotropy, which decreases with increasing temperature. To estimate a degree of the effect of interparticle interactions on the results obtained and to correctly determine the temperature range of the superparamagnetic (or blocked) state, the static magnetic measurement and Mössbauer spectroscopy data have been obtained and analyzed. It has been shown that the most striking feature of the FMR spectra - a gap in the field-frequency dependences - is a manifestation of individual characteristics of ferrihydrite nanoparticles. The induced anisotropy is caused by freezing of a subsystem of surface spins and its coupling with the particle core, which is observed in both samples at a temperature of ∼80 K. The temperature range (below 80 K) in which the gap exists corresponds to the blocked state in the FMR technique. In sample FH-bact, the ratio between the FMR parameters HA and linewidth ΔH obeys the standard expression HA ∼ (ΔH)3. In sample FH-chem, however, the interparticle magnetic interactions dramatically affect the behavior of parameters of the FMR spectra, which change nonmonotonically upon temperature variation. This fact is attributed to the collective freezing of the magnetic moments of particles under the conditions of sufficiently strong interactions, which follows from the temperature dependence of the particle magnetic moment relaxation time determined from the Mössbauer spectroscopy and static magnetometry data obtained in weak magnetic fields.
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16.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Gunyakov V. A., Sutormin V. S., Myslivets S. A., Shabanov V. F., Zyryanov V. Ya.
Заглавие : Synchronously controlled optical modes in the transmittance and reflectance spectra of multilayer photonic structure with dual-frequency nematic liquid crystal
Место публикации : Phys. Rev. E. - 2022. - Vol. 105, Is. 2. - Ст.024702. - ISSN 2470-0045, DOI 10.1103/PhysRevE.105.024702. - ISSN 2470-0053(eISSN)
Примечания : Cited References: 31
Предметные рубрики: ANGULAR-DEPENDENCE
DEFECT MODES
FILTER
TRANSMISSION
MODULATION
Аннотация: A method for electrically controlled synchronous mode tuning in the transmittance and reflectance spectra of a photonic structure consisting of an asymmetric dielectric Fabry-Perot microcavity and an ultrathin metallic film has been proposed. The excitation of a broadband Tamm plasmon polariton at a metal/Bragg mirror interface is accompanied by the two phenomena opposing one another. Due to the strong absorption induced by the metal, a sufficient rejection level in the reflection of the off-resonant radiation has been obtained in a wide spectral range, which almost coincides with the photonic band gap, while at the cavity mode frequencies the structure becomes transparent for the reflected radiation. This leads to the appearance of a series of narrow resonance peaks in the reflectance spectra that coincide in frequency with the transmittance peaks. Based on the structural transformations in the dual-frequency nematic liquid crystal used as a photonic structure defect, the tuning of the modes corresponding to the extraordinary waves to both the short- and long-wavelength spectral ranges has been implemented.
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17.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Gao P. -X., Dong P., Zhou Z. -Y., Zhang X. -J., Li Y. -N., Yang J. -K., Li Q., Chen K., Molokeev M. S., Zhou Z., Xia M.
Заглавие : Novel far-red phosphors (La, Gd, Y)2MgTiO6:Cr3+ with tunable luminescence spectra for grow light
Разночтения заглавия :
Место публикации : Faguang Xuebao/Chin. J. Lumines. - 2022. - Vol. 43, Is. 1. - P.58-68. - ISSN 10007032 (ISSN), DOI 10.37188/CJL.20210327
Примечания : Cited References: 27. - Supported by National Natural Science Foundation of China(51974123); The Distinguished Youth Foundation of Hunan Province(2020JJ2018); Key R & D Projects in Hunan Province(2020WK2016&2020SK2032&2022NK2044), Hunan High Level Talent Gathering Project(2019RS1077&2020RC5007); Natural Science Foundation of Hunan Province(2021JJ40261); The Scientific Research Fund of Hunan Provincial Education Department(19C0903); The Natural Sciences Foundation of Hunan Agricultural University(19QN11); Hunan Provincial Key Laboratory of Crop Germplasm Innovation and Resource Utilization Science Foundation(19KFXM12); Changsha Science and Technology Plan(KH2005114)
Аннотация: Cr3+-activated double perovskite structure phosphor has drawn wide attention due to its far-red and near-infrared emission. In this work, we synthesized a series of (La,Gd,Y)2MgTiO6∶Cr3+ phosphors which can be excited by ultraviolet light of about 345 nm, and the emission bands are in the range of 700-900 nm. The spectra were tuned by ions substitution strategy. The main emission peaks were blue shifted from 766 nm to 737 nm and 757 nm by substituting the La site with Gd and Y, respectively. Meanwhile, the thermal stability at 150 ℃ increased from 41.7% to 69.1% and 67%, respectively. The crystal structure, microstructure, decay time, thermal stability and band gap were investigated systematically. The substitution of Gd/Y ions causes the lattice contraction, which results in the change of the nephelauxetic effect, and eventually leads to the blue shift of the spectra. The emission spectra of these phosphors have good matching with the 730 nm absorption peak of phytochrome FR(PFR), indicating their application prospect in plant growth lighting. Cationic substitution strategy can regulate the luminescence properties of Cr3+, which provides ideas for the development of phosphors for plant growth lamps in the future.
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18.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Krylov A. S., Pavlovskiy M. S., Kitaev Y., Gudim I. A., Andryshin N. D., Vtyurin A. N., Jiang, Qinghui, Krylova S. N.
Заглавие : Phase transitions and p–T phase diagram of the multiferroic TbFe3(BO3)4 crystal
Коллективы : Russian Foundation for Basic ResearchRussian Foundation for Basic Research (RFBR); RFBR, Krasnoyarsk Territory and Krasnoyarsk Regional Fund of Science [20-42-240009]; Russian Foundation for Basic Research and DFG (Deutsche Forschungsgemeinschaft)German Research Foundation (DFG) [448809307, 21-52-12018]
Место публикации : J. Raman Spectrosc. - 2022. - Vol. 53, Is. 6. - P.1179-1187. - ISSN 0377-0486, DOI 10.1002/jrs.6341. - ISSN 1097-4555(eISSN)
Примечания : Cited References: 48. - Russian Foundation for Basic Research; RFBR, Krasnoyarsk Territory and Krasnoyarsk Regional Fund of Science, Grant/Award Number: 20-42-240009; Russian Foundation for Basic Research and DFG (Deutsche Forschungsgemeinschaft), Grant/Award Numbers: 448809307, 21-52-12018
Предметные рубрики: BILBAO CRYSTALLOGRAPHIC SERVER
RAMAN-SPECTRA
HIGH-TEMPERATURE
Аннотация: The structural phase transitions in multiferroic TbFe3(BO3)4 with change hydrostatic pressures and temperatures have been studied by Raman spectroscopy and calculation within density functional theory. Lattice dynamics calculations in the TbFe3(BO3)4 crystal in the ��32 phase under various values of applied hydrostatic pressure (from 0 up to 5 GPa with 1 GPa step) were performed. The calculation performed in this work in a TbFe3(BO3)4 crystal showed that the applied pressure can increase the phase transition temperature. Raman spectra of the TbFe3(BO3)4 crystal have been investigated at simultaneously high temperature and high pressure (up to 5.14 GPa and 465 K). The appearance of a soft mode was observed with decreasing temperature at normal pressure. The manifestations of the interaction of the structural and magnetic order parameters in the range from 13 to 50 K were observed at normal pressure. With increasing pressure and a fixed temperature, recovery of the soft modes is also observed. The experimental p–T phase diagram of TbFe3(BO3)4 was established. An increase in pressure leads to an increase in the temperature of transition.
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19.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Igumenov A. Yu., Andryushchenko T. A.
Заглавие : Different approaches for SiO2 inelastic electron scattering cross section spectra dissolving
Коллективы : Reshetnev Readings 2019
Место публикации : IOP Conf. Ser.: Mater. Sci. Eng. - 2022. - Vol. 1230: Reshetnev Readings 2019 11th-15th November 2019, Krasnoyarsk, Russian Federation. - Ст.012007. - ISSN 17578981 (ISSN), DOI 10.1088/1757-899X/1230/1/012007. - ISSN 1757899X (eISSN)
Примечания : Cited References: 14. - The authors express gratitude to Parshin A.S. for assignation the SiO2 Kλ-spectra
Аннотация: Inelastic electron scattering cross section spectra (Kλ-spectra) of SiO2 were dissolved into bulk-loss and surface-loss components using factor analysis and Tougaard functions approximation. Primary electron energy dependences of various components intensities were received. It was shown that joint using of factor analysis and Tougaard functions approximation allows receiving more reliable results in inelastic electron scattering cross section spectra studies.
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20.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Gerasimova Yu. V., Krylov A. S., Vtyurin A. N., Laptash N. M., Pogoreltsev E. I., Dubrovskiy A. A., Gerasimov M. A.
Заглавие : Dynamic processes of the water sublattice in FeTiF6·xH2O·yD2O crystal
Место публикации : J. Raman Spectrosc. - 2022. - Vol. 53, Is. 10: Special Issue: Vibrational Spectroscopy of Water. - P.1704-1709. - ISSN 03770486 (ISSN), DOI 10.1002/jrs.6430
Примечания : Cited References: 31. - The reported study was funded by the Russian Foundation for Basic Research, Government of Krasnoyarsk Territory and Krasnoyarsk Regional Foundation of Science according to the research project “Spectral and magnetic properties of single crystals of transition metal fluoride hexahydrates” No. 20-42-240014
Аннотация: Phase transition in FeTiF6·xH2O·yD2O crystals has been studied by Raman spectroscopy. The 611 cm-1 line corresponding to mode A1g of [TiF6]2- system does not exhibit anomalous behavior associated with the phase transition. The temperature studies showed that below the phase transition temperature, the equivalence of D2O molecules in FeTiF6·xH2O·yD2O octahedron is broken. The phase transition mechanism in the compound under study is associated with Fe(xH2O·yD2O) complex.
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