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

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Каталог книг и брошюр библиотеки ИФ СО РАН

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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Bataleva Y. V., Palyanov Y. N., Borzdov Y. M., Novoselov I. D., Bayukov O. A.
Заглавие : An effect of reduced S-rich fluids on diamond formation under mantle-slab interaction
Место публикации : Lithos. - 2019. - Vol. 336-337. - P.27-39. - ISSN 00244937 (ISSN), DOI 10.1016/j.lithos.2019.03.027
Примечания : Cited References: 73. - This work was supported by the Russian Science Foundation under Grant No. 14-27-00054 and a state assignment of IGM SB RAS. The authors thank S. Ovchinnikov for his assistance in implementation of the Mossbauer spectroscopy measurements.
Аннотация: Experimental study, dedicated to understanding the effect of S-rich reduced fluids on the diamond-forming processes under subduction settings, was performed using a multi-anvil high-pressure split-sphere apparatus in Fe3C-(Mg,Ca)CO3-S and Fe0-(Mg,Ca)CO3-S systems at the pressure of 6.3 GPa, temperatures in the range of 900–1600 °C and run time of 18–60 h. At the temperatures of 900 and 1000 °C in the carbide-carbonate-sulfur system, extraction of carbon from cohenite through the interaction with S-rich reduced fluid, as well as C0-producing redox reactions of carbonate with carbide were realized. As a result, graphite formation in assemblage with magnesiowüstite, cohenite and pyrrhotite (±aragonite) was established. At higher temperatures (≥1100 °C) formation of assemblage of Fe3+-magnesiowüstite and graphite was accompanied by generation of fO2-contrasting melts - metal-sulfide with dissolved carbon (Fe-S-C) and sulfide-oxide (Fe-S-O). In the temperature range of 1400–1600 °C spontaneous diamond nucleation was found to occur via redox interactions of carbide or iron with carbonate. It was established, that interactions of Fe-S-C and Fe-S-O melts as well as of Fe-S-C melt and magnesiowüstite, were С0-forming processes, accompanied by disproportionation of Fe. These resulted in the crystallization of Fe3+-magnesiowüstite+graphite assemblage and growth of diamond. We show that a participation of sulfur in subduction-related elemental carbon-forming processes results in sharp decrease of partial melting temperatures (~300 °C), reducting the reactivity of the Fe-S-C melt relatively to FeC melt with respect to graphite and diamond crystallization and decrease of diamond growth rate.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Aver'yanov E. M.
Заглавие : Influence of nematic and smectic orders on polarizability of molecules of ethyl-p-(4-ethoxybenzylideneamino-)alpha-methyl cinnamate liquid crystals
Место публикации : Phys. Solid State: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2013. - Vol. 55, Is. 11. - P.2391-2396. - ISSN 1063-7834, DOI 10.1134/S1063783413110048
Примечания : Cited References: 16
Предметные рубрики: TRANSITION
MBBA
Аннотация: Experimental values of the polarizability tensor gamma components of molecules of ethyl-p-(4-ethoxybenzylideneamino-)alpha-methyl cinnamate liquid crystals in the nematic and smectic A phases have been obtained. Quadratic dependences of the longitudinal, gamma (l) , and transverse, gamma (t) , components, the mean value , and anisotropy Delta gamma in both phases have been established as functions of the orientational order parameter S of molecules in a maximally wide range of S. The nematic-smectic A phase transition with a continuous variation of S manifests itself as kinks in the linear dependences of , Delta gamma, and gamma (l) on S (2) and does not influence the dependence gamma (t) (S (2)). The observed dependences have been derived in the framework of the theory of the nematic-smectic A phase transition. The factors responsible for different influences of the orientational and positional orderings of molecules on the polarizability parameters have been determined.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Balaev D. A., Semenov S. V., Petrov M. I.
Заглавие : Dominant influence of the compression effect of a magnetic flux in the intergranular medium of a granular high-temperature superconductor on dissipation processes in an external magnetic field
Место публикации : Physics of the Solid State. - 2013. - Vol. 55, Is. 12. - P.2422-2430. - ISSN 1063-7834, DOI 10.1134/S1063783413120044
Аннотация: Experiments have been presented that demonstrate the effect of the compression of a magnetic flux in grain boundaries of a granular high-temperature superconductor in an external magnetic field on the dissipation processes. The compression of the magnetic flux is associated with the diamagnetic behavior of superconducting grains and the existence of a Josephson medium in grain boundaries. Under these conditions, grain boundaries are in an effective magnetic field that depends on the magnetic state (magnetization) of the superconducting grains. Based on the analysis of experimental data (dependences of the electrical resistance R and magnetization on the magnetic field H and temperature T, as well as current-voltage characteristics), the conclusion has been drawn that it is the temperature evolution of the effective magnetic field in the intergranular medium which primarily determines the behavior of the dependences R(T) in weak external magnetic fields of no more than ?103 Oe. This should be taken into account in the interpretation of experiments on the magnetoresistance effect in granular high-temperature superconductors in terms of different theories. The conclusion drawn here also implies a significant correction of the previously obtained results.
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Вид документа : Статья из сборника (однотомник)
Шифр издания :
Автор(ы) : Dubinina I. A., Dudnik A. I., Vnukova N. G., Churilov G. N.
Заглавие : Comparative study of antioxidant activity of fullerenols including higher and endohedral fullerenols by inhibition of adrenaline autoxidation
Коллективы : "Advanced carbon nanostructures", International conference
Место публикации : International Conference Advanced Carbon Nanostructures: abstracts of invited lectures & contributed papers. - 2015. - P.63
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Mikhaleva E. A., Flerov I. N., Kartashev A. V., Gorev M. V., Bogdanov E. V., Bondarev V. S., Korotkov L. N., Rysiakiewicz-Pasek E.
Заглавие : Effect of a restricted geometry on thermal and dielectric properties of NH4HSO4 ferroelectric
Коллективы : Russia/CIS/Baltic/Japan Symposium on Ferroelectricity , Russian Foundation for Basic Research (RFBR) [16-32-00092 mol_a]
Место публикации : Ferroelectrics. - 2017. - Vol. 513, Is. 1. - P.44-50. - ISSN 0015-0193, DOI 10.1080/00150193.2017.1350436. - ISSN 1563-5112(eISSN)
Примечания : Cited References:17. - The reported study was partially supported by the Russian Foundation for Basic Research (RFBR), research project No. 16-32-00092 mol_a.
Предметные рубрики: PHASE-TRANSITIONS
AMMONIUM
CAPACITY
SULFATE
KH2PO4
Ключевые слова (''Своб.индексиров.''): ferroelectric--phase transition--porous glass--nanocomposite
Аннотация: Heat capacity, thermal dilatation, sensitivity to pressure and permittivity of NH4HSO4 embedded into glass matrices with a pore size of 320 nm and 46 nm were studied. Large difference in the thermal expansion of both glass and ferroelectric leads to a "clamped" state of NH4HSO4 in nanocomposites and to the phase transition temperatures change. The restricted geometry does not effect on the order of successive transformations in NH4HSO4 but is accompanied by a significant reduction in entropy of phase transitions. The behavior of DTA-signal and permittivity show the expansion of the temperature range of the ferroelectric phase under hydrostatic pressure.
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Вид документа : Статья из сборника (однотомник)
Шифр издания :
Автор(ы) : Mikhaleva E. A., Flerov I. N., Kartashev A. V., Gorev M. V., Bogdanov E. V., Bondarev V. S., Korotkov L. N., Dotsenko I. I., Rysiakiewicz-Pasek E.
Заглавие : Effect of a restricted geometry on thermal and dielectric properties of NH4HSO4 ferroelectric
Коллективы : Russia/CIS/Baltic/Japan Symposium on Ferroelectricity, International Workshop on Relaxor Ferroelectrics
Место публикации : Joint 13th Russia/CIS/Baltic/Japan Symp. on Ferroelectricity and Int. Workshop on Relaxor Ferroelectrics (RCBJSF-IWRF 2016): book of abstracts. - 2016. - Ст.P-18
Примечания : References: 2
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Shtarev D. S., Kevorkyants R., Molokeev M. S., Shtareva A. V.
Заглавие : Effect of composition on the optical and photocatalytic properties of visible light responsive materials Bi26-xMgxO40
Место публикации : Inorg. Chem. - 2020. - Vol. 59, Is. 12. - P.8173-8183. - ISSN 00201669 (ISSN), DOI 10.1021/acs.inorgchem.0c00486
Примечания : Cited References: 41. - This study was supported by a grant from the Russian Science Foundation (Project No 19-73-10013). The authors acknowledge the help of the Yu. A. Kosygin Institute of Tectonics and Geophysics FEB RAS in conducting the study and offering their research equipment. The authors also thank the Research Center on Nanophotonics, the Center for Physical Methods of Surface Investigation (Dr. Alexandra Koroleva), and the Computing Centre of the Saint-Petersburg State University. R.K. acknowledges financial support from a grant from the Saint-Petersburg State University (Pure ID 39054581)
Аннотация: We report the synthesis and the crystal and electronic structure as well as the optical and photocatalytic properties of novel photoactive materials of the general formula Bi26–xMgxO40. Two compounds with compositions of Bi24.28(3)Mg1.72(3)O40 and Bi24.05(3)Mg1.95(3)O40 are synthesized using the pyrolytic method. According to X-ray diffraction analysis, the materials are monocrystalline species. Their electronic bandgaps determined from Tauc plots are 2.41 eV [Bi24.28(3)Mg1.72(3)O40] and 2.69 eV [Bi24.05(3)Mg1.95(3)O40]. Keeping in mind that optical bandgaps are typically larger than their electronic counterparts, we find that the bismuthate bandgaps match well that of Bi24Mg2O40 (2.26 eV) predicted by density functional theory. Apparently, the synthesized bismuthates are indirect bandgap semiconductors just like Bi24Mg2O40. Both materials demonstrate nearly identical luminescence spectra. Their luminescence emission at 620 nm is most efficiently excited by 365 nm light. The materials’ photocatalytic properties are evaluated in a visible light-induced photocatalytic phenol degradation reaction. Rather low activity of both compounds is detected. However, Bi24.05(3)Mg1.95(3)O40 is ∼2 times more photocatalytically active than Bi24.28(3)Mg1.72(3)O40, which is associated with a higher Bi5+ content in the former.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Rudyak V. Y., Krakhalev M. N., Gardymova A. P., Abdullaev A. S., Alekseev A. A., Zyryanov V. Ya.
Заглавие : Effect of elastic constants on electrically induced transition in twisted radial cholesteric droplets
Место публикации : Sci. Rep. - 2022. - Vol. 12, Is. 1. - Ст.9565. - ISSN 20452322 (ISSN), DOI 10.1038/s41598-022-13612-4
Примечания : Cited References: 42. - This research was funded by Russian Science Foundation, Grant No. 20-72-10038. The research was carried out using the equipment of the shared research facilities of HPC computing resources at Lomonosov Moscow State University
Аннотация: In this work, we investigated the behavior of cholesteric droplets with homeotropic boundary conditions experimentally and by computer simulations. Small droplets forming twisted radial structures were studied. We obtained two different paths of structural transformations under electric field in such droplets. The choice between these paths has probabilistic nature. The ratio between the two transition types was found to be sensitive to the elastic constants of LC forming the droplet. We suggest the principal approach for in situ estimation of ratios between elastic constants in cholesteric LCs deposited in polymer-dispersed LC material and discuss its strong and weak sides.
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Вид документа : Статья из сборника (однотомник)
Шифр издания :
Автор(ы) : Mukhin A. A., Ivanov V. Yu., Tikhanovskii A. Yu., Gudim I. A.
Заглавие : Effect of electric field on magnetization and magnetic susceptibility in rare-earth ferroborite multiferroics
Коллективы : Российская академия наук, Уральское отделение РАН, Институт физики металлов им. М. Н. Михеева Уральского отделения РАН, Уральский федеральный университет им. первого Президента России Б.Н. Ельцина, Российский фонд фундаментальных исследований, Euro-Asian Symposium "Trends in MAGnetism", "Trends in MAGnetism", Euro-Asian Symposium
Место публикации : Euro-asian symposium "Trends in magnetism" (EASTMAG-2019): Book of abstracts/ чл. конс. ком.: S. G. Ovchinnikov, N. V. Volkov [et al.] ; чл. прогр. ком. D. M. Dzebisashvili [et al.]. - 2019. - Vol. 2. - Ст.K.O8. - P.312-313. - ISBN 978-5-9500855-7-4 (Шифр В33/E12-125657784)
Примечания : Cited References: 3. - This work was supported by the Russian Science Foundation (project 16-12-10531)
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10.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Sandalov I. S., Zamkova N. G., Zhandun V. S., Tarasov I. A., Varnakov S. N., Yakovlev I. A., Solovyov L. A., Ovchinnikov S. G.
Заглавие : Effect of electron correlations on the Fe3Si and α- FeSi2 band structure and optical properties
Коллективы : Russian Fund of Basic Research [14002-00186, 13-02-01265]; President of Russia Grants [2886.2014.2, 924.2014.2]
Место публикации : Phys. Rev. B: American Physical Society, 2015. - Vol. 92, Is. 20. - Ст.205129. - ISSN 1098-0121, DOI 10.1103/PhysRevB.92.205129. - ISSN 1550-235X(eISSN)
Примечания : Cited References:69. - The theoretical part of this work was supported by Russian Fund of Basic Research, Grant No. 14002-00186 and the President of Russia Grants No. 2886.2014.2 and No. 924.2014.2 for support of Leading Scientific School. The calculations were performed with the computer resources of NRC "Kurchatov Institute" (ui2.computing.kiae.ru). The experimental work was supported by Russian Fund of Basic Research, Grant No. 13-02-01265. I.S. thanks A. Ruban for useful discussion.
Предметные рубрики: DENSITY-FUNCTIONAL THEORY
TOTAL-ENERGY CALCULATIONS
AUGMENTED-WAVE METHOD
BASIS-SET
METALS
ABSORPTION
EMISSION
SURFACES
ALLOYS
LAYERS
Аннотация: We use the Vienna ab initio simulation package (vasp) for evaluation of the quasiparticle spectra and their spectral weights within Hedin's GW approximation (GWA) for Fe3Si and α-FeSi2 within the non-self-consistent one-shot approximation G0W0 and self-consistent scGWA with the vertex corrections in the particle-hole channel, taken in the form of two-point kernel. As input for G0W0, the band structure and wave functions evaluated within the generalized gradient corrected local-density approximation to density functional theory (GGA) have been used. The spectral weights of quasiparticles in these compounds deviate from unity everywhere and show nonmonotonic behavior in those parts of bands where the delocalized states contribute to their formation. The G0W0 and scGWA spectral weights are the same within 2%–5%. The scGWA shows a general tendency to return G0W0 bands to their GGA positions for the delocalized states, while in the flat bands it flattens even more. Variable angle spectroscopic ellipsometry measurements at T=296 K on grown single-crystalline ∼50-nm-thick films of Fe3Si on n-Si(111) wafer have been performed in the interval of energies ω∼(1.3–5) eV. The comparison of G0W0 and scGW theory with experimental real and imaginary parts of permittivity, refractive index, extinction and absorption coefficients, reflectivity, and electron energy loss function shows that both G0W0 and scGW qualitatively describe experiment correctly, the position of the low-energy peaks is described better by the scGW theory, however, its detailed structure is not observed in the experimental curves. We suggest that the angle-resolved photoemission spectroscopy experiments, which can reveal the fine details of the quasiparticle band structure and spectral weights, could help to understand (i) if the scGWA with this type of vertex correction is sufficiently good for description of these iron silicides and, possibly, (ii) why some features of calculated permittivity are not seen in optical experiments.
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11.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Gao H., Molokeev M. S., Chen Q., Yang X., Wang X., Ma B.
Заглавие : Effect of ligand environment of rare-earth ions on temperature measurement performance of SrAO4:xEu3+ (A = Mo and W) phosphors
Место публикации : Ceram. Int. - 2022. - Vol. 48, Is. 24. - P.36835-36844. - ISSN 02728842 (ISSN), DOI 10.1016/j.ceramint.2022.08.247
Примечания : Cited References: 58. - This work was supported by the National Natural Science Foundation of China (Grant No. 51802172) and the Natural Science Foundation of Qinghai Province (Grant No. 2021-ZJ-713)
Аннотация: Molybdate and tungstate with scheelite-type structure are excellent self-luminescent materials, which can be used as ideal hosts for the doping of rare-earth ions. In this study, a series of Eu3+-activated SrAO4 (A = Mo and W) phosphors were successfully synthesized, and their crystal structures, photoluminescence properties, and temperature measurement performance were analyzed in detail. These phosphors were excited by UV light (291 nm and 247 nm, respectively), with clear energy transfer (ET) (MoO42−→Eu3+ or WO42−→Eu3+). According to fluorescence intensity ratio (FIR) and Judd–Ofelt (J–O) theory, compared to SrWO4:0.01Eu3+ phosphor, SrMoO4:0.01Eu3+ phosphor exhibited better thermal stability, with relatively low Sa value (maximum values were 5.082 %K−1 and 20.74 %K−1, respectively), and their Sr values were not significantly different (maximum values were 0.864 %K−1 and 0.83 %K−1, respectively). Sa value was negatively correlated to central asymmetry of Eu3+, but the optimal Sr value tended to be more suitable for central asymmetry of Eu3+. In addition, Eu3+ exhibited stronger central asymmetry as well as covalency of Eu–O bond in SrMoO4. Results reveal that SrMoO4:xEu3+ and SrWO4:xEu3+ can be used for luminescent thermometers.
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12.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Zamkova N. G., Zhandun V. S., Ovchinnikov S. G., Sandalov I. S.
Заглавие : Effect of local environment on moment formation in iron silicides
Место публикации : J. Alloys Compd.: Elsevier, 2017. - Vol. 695. - P.1213-1222. - ISSN 09258388 (ISSN), DOI 10.1016/j.jallcom.2016.10.248
Примечания : Cited References: 40. - This work was supported by the Grants of Russian Foundation for Basic Research № 14-02-00186, № 17-02-00161 and by the Grants of Russian Foundation for Basic Research and Government of Krasnoyarsk Territory № 16-42-243035, 16-42-242036. The authors would like to thank AS Shinkorenko for the technical support.
Ключевые слова (''Своб.индексиров.''): ab initio calculations--iron silicides--magnetic properties--multiorbital model--spin-crossover
Аннотация: he effect of local environment on the formation of magnetic moments on Fe atoms in iron silicides is studied by combination of ab initio and model calculations. The suggested model includes all Fe d- and Si p-orbitals, intra-atomic Coulomb interactions, inter-atomic Fe-Fe exchange and hopping of electrons to nearest and next nearest neighboring atoms. The parameters of the model are found from the requirement that self-consistent moments on atoms and density of states found from ab initio and model calculations within the Hartree-Fock approximation are close to each other as much as possible. Contrary to the commonly accepted statement that in the ordered Fe3Si and FexSi1−x alloys an increase of the Si concentration within nearest environment of Fe atoms results in a decrease of Fe magnetic moment we find that a crucial role in the formation of magnetic moments is played by the second coordination sphere of Fe atoms. Particularly, the Fe atoms have higher magnetic moments in amorphous films compared to the epitaxial ones due to decreasing the number of iron-atoms in the next nearest environment. Both our model and ab initio calculations confirm existence of known spin crossover with pressure and predict second crossover at higher pressure.
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13.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Kagan M.Yu., Val'kov V. V., Mitskan V. A., Korovushkin M. M.
Заглавие : Effect of long-range interactions on the Kohn-Luttinger mechanism of the cooper instability in the Shubin-Vonsowsky model
Место публикации : JETP letters. - 2013. - Vol. 97, Is. 4. - P.226-232. - DOI 10.1134/S0021364013040085
Аннотация: The problem of Cooper instability is studied by implementing the Kohn–Luttinger mechanism in the frame-work of the Shubin–Vonsowsky model taking into account the intersite Coulomb interactions within the first and second coordination spheres. It is shown that the Kohn–Luttinger renormalization for the effective interaction in the second order terms of perturbation theory, as well as the inclusion of intersite hoppings in the second and third coordination spheres, significantly affects the interplay between the superconducting phases with dxy-, p-, s-, and dx2-y2 -wave symmetries of the order parameter.
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14.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Smolyakov D. A., Tarasov A. S., Shanidze, Lev, Bondarev I. A., Baron F. A., Lukyanenko A. V., Yakovlev I. A., Volochaev M. N., Volkov N. V.
Заглавие : Effect of magnetic and electric fields on the AC resistance of a silicon-on-insulator-based transistor-like device
Коллективы : RFBR, Krasnoyarsk Territory and Krasnoyarsk Regional Fund of Science [20-42-243007, 20-42-240013]; Government of the Russian Federation; Mega-grant for the Creation of Competitive World-Class Laboratories [075-15-2019-1886]
Место публикации : Phys. Status Solidi A. - 2022. - Vol. 219. Is. 1. - Ст.2100459. - ISSN 1862-6300, DOI 10.1002/pssa.202100459. - ISSN 1862-6319(eISSN)
Примечания : Cited References: 19. - The authors thank the Krasnoyarsk Territorial Center for Collective Use, Krasnoyarsk Scientific Center of the SB RAS, for electron microscope investigations. This study was supported by RFBR, Krasnoyarsk Territory and Krasnoyarsk Regional Fund of Science, projects nos. 20-42-243007 and 20-42-240013, and by the Government of the Russian Federation, the Mega-grant for the Creation of Competitive World-Class Laboratories, agreement no. 075-15-2019-1886
Предметные рубрики: NANOSTRUCTURES
Аннотация: Herein, the AC magnetoresistance (MR) in the silicon-on-insulator (SOI)-based Fe/Si/SiO2/p-Si structure is presented. The structure is used for fabricating a back-gate field-effect pseudo-metal-oxide-semiconductor field-effect transistor (MOSFET) device. The effects of the magnetic field and gate voltage on the transport characteristics of the device are investigated. Magnetoimpedance value of up to 100% is obtained due to recharging of the impurity and surface centers at the insulator/semiconductor interface. A resistance variation of up to 1000% is found, which is caused by the voltage applied to the gate and the field effect on the band structure of the sample. Combining the magnetic and electric fields, one can either change the absolute value of the AC resistance while having the MR fixed or change the sign and character of the field dependence of the MR. The observed effects can be used in the development of magnetic-field-driven SOI-based devices and high-frequency circuits.
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15.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Arauzo A., Bartolome J., Luzon J., Drokina T. V., Petrakovskii G. A., Molokeev M. S.
Заглавие : Effect of R substitution in spin glass RFeTi2O7 compounds
Место публикации : J. Magn. Magn. Mater. - 2020. - Vol. 515. - Ст.167273. - ISSN 03048853 (ISSN), DOI 10.1016/j.jmmm.2020.167273
Примечания : Cited References: 38. - This study has been financed by MECOM Project MAT2014-53921-R, MICINN Project MAT2017-83468-R and Gobierno de Aragón RASMIA E12_17R. Authors would like to acknowledge the use of Servicio General de Apoyo a la Investigación-SAI, Universidad de Zaragoza
Аннотация: Zirconolite oxides R3+Fe3+Ti2O7 (R rare earth element) are known to exhibit spin glass behaviour at low temperatures. Here we present a detailed study of these compounds for R = Eu, Gd, Dy, Ho, and Er, together with reviewed previous measurements on Sm, Tb, Tm, Yb and Lu, with the scope of determining the role played by the rare earth on their magnetic properties. They have been investigated using X-ray powder diffraction, and further characterized by magnetization, frequency dependent ac susceptibility and heat capacity measurements. RFeTi2O7 compounds are all isostructural showing orthorhombic structure, space group Pcnb at 300 K. Disorder of the magnetic ions in the RFeTi2O7 lattice induces spin glass behaviour at low temperatures, mainly due to the Fe sublattice. We show that magnetic rare earth ions participate in the spin glass state tuning its properties. The single ion anisotropy of the R3+ ions, excluding exchange interaction with other magnetic ions, has been calculated by ab initio methods, and expressed in terms of the g tensor of the ground doublet or quasi-doublet in Kramers (Sm, Dy, Er, Yb) and non-Kramers (Tb, Ho) ions, respectively, in an effective spin S* = 1/2 model. In the case of R with a singlet ground state (Eu, Tm) or a multiplet state (Gd), the ion is isotropic. We show that the relative increase in the spin-glass temperature ΔTSGR/TSGFe with respect to the LuFeTi2O7, where Lu is non-magnetic, correlates qualitatively with the product of the ratio gz/gJ (R = Tb, Dy, Ho, and Er), or g⊥/gJ (R = Sm), times the ratio of exchange interactions JR,Fe/JFe,Fe determined from the paramagnetic room temperature susceptibility measurements. Besides, for increasing anisotropy the spin glass transition dynamics slows down to values typical of cluster glass. The coercive field below the transition is increased in the same trend. This paper explains the effect of the R-Fe exchange interaction and R single ion anisotropy on the spin-glass behaviour of these compounds.
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16.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Mikhaleva E. A., Flerov I. N., Kartashev A. V., Gorev M. V., Molokeev M. S., Bogdanov E. V., Bondarev V. S., Korotkov L. N., Rysiakiewicz-Pasek E.
Заглавие : Effect of restricted geometry and external pressure on the phase transitions in ammonium hydrogen sulfate confined in a nanoporous glass matrix
Место публикации : J. Mater. Sci. - 2018. - Vol. 53, Is. 15. - P.12132–12144. - ISSN 00222461 (ISSN), DOI 10.1007/s10853-018-2467-1
Примечания : Cited References: 44. - The reported study was funded by Russian Foundation for Basic Research (RFBR) according to the Research Project No. 16-32-00092 mol_a.
Ключевые слова (''Своб.индексиров.''): hydraulics--hydrostatic pressure--permittivity--pore size--specific heat--sulfur compounds--thermal expansion
Аннотация: A study of heat capacity, thermal dilatation, susceptibility to hydrostatic pressure, permittivity and polarization loops was carried out on NH4HSO4–porous glass nanocomposites (AHS + PG) as well as empty glass matrices. The formation of dendrite clusters of AHS with a size, dcryst, exceeding the pore size was found. An insignificant anisotropy of thermal expansion of AHS + PG showing statistically uniform distribution of AHS with random orientations of nanocrystallites over the matrix was observed. The effect of internal and external pressures on thermal properties and permittivity was studied. At the phase transition P-1 ↔ Pc, a strongly nonlinear decrease in the entropy ΔS2 and volume strain (ΔV/V)T2 was observed with decreasing dcryst. The linear change in temperatures of both phase transitions P-1 ↔ Pc ↔ P21/c under hydrostatic pressure is accompanied by the expansion of the temperature range of existence of the ferroelectric phase Pc, while this interval narrows as dcryst decreases.
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17.

Вид документа : Статья из журнала
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Автор(ы) : Tsipotan A. S., Gerasimova M. A., Aleksandrovsky A. S., Zharkov S. M., Slabko V. V.
Заглавие : Effect of visible and UV irradiation on the aggregation stability of CdTe quantum dots
Место публикации : J. Nanopart. Res.: Springer, 2016. - Vol. 18, Is. 11. - P.324-8. - ISSN 13880764 (ISSN), DOI 10.1007/s11051-016-3638-0
Примечания : Cited References: 23
Ключевые слова (''Своб.индексиров.''): nanotechnology--quantum dots--photostimulated aggregation--photostability--colloids--laser-induced self-assembly
Аннотация: The possibility of controlling the aggregation stability of CdTe quantum dots (QDs) stabilized by thioglycolic acid (TGA) is important for implementation of quasi-resonant laser-induced self-assembly. This study examines the influence of irradiation by the UV as well as by the visible light on the photostimulated aggregation of QDs. Different photochemical mechanisms are identified, depending on whether light wavelength falls into an interband transition or the first exciton transition. Irradiation by visible light does not lead to changes in the absorption spectra but decreases luminescence intensity through the detachment of TGA and the formation of dangling bonds, leading to the creation of radiativeless relaxation centers. UV irradiation (in the 300–370 nm range), at an intensity of 0.4 W/cm2, initially (during the first 75 min) leads to the degradation of the stabilizer and QDs’ surface. After 75 min of combined UV and visible light irradiation, a gradual increase in spontaneous aggregation takes place, testifying excessive decrease in stabilizing potential barrier height. Hence, the laser-induced self-assembly of CdTe QDs is recommended to be performed over a time period of between 80 and 100 min after the beginning of low-intensity UV irradiation under conditions equivalent to those applied in this study. © 2016, Springer Science+Business Media Dordrecht.
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18.

Вид документа : Статья из журнала
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Автор(ы) : Cheng F., Xia, Zhiguo, Molokeev M. S., Jing X.
Заглавие : Effects of composition modulation on the luminescence properties of Eu3+ doped Li1-xAgxLu(MoO4)2 solid-solution phosphors
Место публикации : Dalton Trans.: Royal Society of Chemistry, 2015. - Vol. 44, Is. 41. - P.18078-18089. - ISSN 1477-9226, DOI 10.1039/c5dt02760h
Примечания : Cited References: 42. - The present work was supported by the National Natural Science Foundations of China (Grant No. 51272242, 51572023, 51511130035), Natural Science Foundations of Beijing (2132050), the Program for New Century Excellent Talents in University of Ministry of Education of China (NCET-12-0950), Beijing Nova Program (Z131103000413047), Beijing Youth Excellent Talent Program (YETP0635), the Funds of the State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences (RERU2015022), and the excellent tutor section of the Fundamental Research Funds for the Central Universities of China University of Geosciences, Beijing (2-9-2015-028). This work was also partly supported by the Russian Foundation for Basic Research (Grant No. 15-52-53080 GFEN_a).
Предметные рубрики: RED PHOSPHORS
PHOTOLUMINESCENCE PROPERTIES
ENERGY-TRANSFER
WHITE LEDS
IONS
NA
POLYMORPHISM
TUNGSTATES
RELAXATION
MOLYBDATES
Аннотация: Double molybdate scheelite-type solid-solution phosphors Li1−xAgxLu1−y(MoO4)2:yEu3+ were synthesized by the solid state reaction method, and their crystal structures and luminescence properties were investigated in detail. The composition modulation and structural evolution of this series of samples were studied and the selected AgEu(MoO4)2, AgLu(MoO4)2, LiLu(MoO4)2 and LiEu(MoO4)2 phases were analyzed based on the Rietveld refinement. Depending on the variation of the Li/Ag ratio in Li1−xAgxLu1−y(MoO4)2:yEu3+ phosphors, the difference in the luminescence properties of Li1−xAgxLu1−y(MoO4)2:yEu3+ phosphors was ascribed to two factors, one reason could be assigned to the coupling effect and the nonradiative transition between the energy levels of LixAg1−xLu(MoO4)2 matrices and the activator Eu3+, another could be due to the near ultraviolet energy absorption and transmission efficiency between the charge-transfer (CT) band of O2−–Mo6+ and the 4f → 4f emissive transitions of Eu3+. The ultraviolet-visible diffuse reflection spectra (UV-vis DRS) and Raman spectra analysis were also used to verify the above mechanism.
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19.

Вид документа : Статья из журнала
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Автор(ы) : Ignatchenko V. A., Polukhin D. S.
Заглавие : Effects of cross correlations between inhomogeneities of the parameters of an isotropic medium on the spectrum and damping of elastic waves
Место публикации : J. Exp. Theor. Phys. - NEW YORK: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2010. - Vol. 110, Is. 2. - С. 345-359. - FEB. - ISSN 1063-7761, DOI 10.1134/S1063776110020184
Примечания : Cited Reference Count: 17. - Гранты: This study was supported in part by the Council on Grants from the President of the Russian Federation for the Support of Leading Scientific Schools (grant no. 3818.2008.3) and the Presidium of the Russian Academy of Sciences (program no. 27.1) and performed within the framework of the Federal Target Program (State Contract no. 02.740.11.0220).Финансирующая организация: Council on Grants from the President of the Russian Federation for the Support of Leading Scientific Schools [3818.2008.3]; Presidium of the Russian Academy of Sciences [27.1]; Federal Target Program [02.740.11.0220]
Ключевые слова (''Своб.индексиров.''): cross correlations--dispersion law--elastic force--inhomogeneities--isotropic medium--negative cross-correlation--physical nature--two parameter--wave spectra--damping--dispersions--elastic waves--hamiltonians--dispersion (waves)
Аннотация: The dispersion and damping laws have been investigated for elastic waves in an isotropic medium with one- and three-dimensional inhomogeneities of the density p(x) of the material and the elastic force constants mu(x) and lambda(x) with allowance for the cross correlations between these inhomogeneities. It has been demonstrated that the positive cross correlations between mu(x) and lambda(x), as well as the negative cross correlations between p(x) and mu(x) or p(x) and lambda(x), lead to an enhancement of the modification of the dispersion law and an increase in the damping of waves. The positive cross correlations between p(x) and mu(x) or p(x) and lambda(x), as well as the negative cross correlations between mu(x) and lambda(x), result in the opposite effects: a weakening of the modification of the dispersion law and a decrease in the damping. An analysis of the results obtained in this paper and in our recent work [15] has made it possible to formulate the general regularity of the effects of cross correlations, irrespective of the physical nature of the waves: the effects of cross correlations between inhomogeneities of any two parameters of the material on the wave spectrum depend on whether both parameters related by the cross correlations belong to the same part of the Hamiltonian (i.e., if they both belong to either the kinetic part or the potential part of the Hamiltonian) or they belong to different parts of the Hamiltonian. The positive cross correlations lead to a greater modification of the dispersion law and to an increase in the damping of waves in the former case and to a decrease in these characteristics in the latter case. Correspondingly, the negative cross correlations in each of these cases result in the opposite effects. This regularity has been explained qualitatively.
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20.

Вид документа : Статья из журнала
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Автор(ы) : Stepin E. A., Sushko E. S., Vnukova N. G., Churilov G. N., Rogova A. V., Tomilin F. N., Kudryasheva N. S.
Заглавие : Effects of endohedral Gd-containing fullerenols with a different number of oxygen substituents on bacterial bioluminescence
Колич.характеристики :19 с
Место публикации : Int. J. Mol. Sci. - 2024. - Vol. 25, Is. 2. - Ст.708. - ISSN 16616596 (ISSN), DOI 10.3390/ijms25020708. - ISSN 14220067 (eISSN)
Примечания : Cited References: 102. - This research was funded by the State Assignment of the Ministry of Science and Higher Education of the Russian Federation, project No. 0287-2021-0020, and partly supported by the Russian Science Foundation No. 23-26-10018, Krasnoyarsk Regional Science Foundation
Аннотация: Gadolinium (Gd)-containing fullerenols are perspective agents for magnetic resonance imaging and cancer research. They combine the unique paramagnetic properties of Gd with solubility in water, low toxicity and antiradical activity of fullerenols. We compared the bioeffects of two Gd-containing fullerenols with a different number of oxygen groups—20 and 42: Gd@C82O20H14 and Gd@C82O42H32. The bioluminescent bacteria-based assay was applied to monitor the toxicity of fullerenols, bioluminescence was applied as a signal physiological parameter, and bacterial enzyme-based assay was used to evaluate the fullerenol effects on enzymatic intracellular processes. Chemiluminescence luminol assay was applied to monitor the content of reactive oxygen species (ROS) in bacterial and enzymatic media. It was shown that Gd@C82O42H32 and Gd@C82O20H14 inhibited bacterial bioluminescence at 10?1 and 10?2 gL?1, respectively, revealing a lower toxicity of Gd@C82O42H32. Low-concentration (10?3–10?1 gL?1) bacterial bioluminescence activation by Gd@C82O42H32 was observed, while this activation was not found under exposure to Gd@C82O20H14. Additional carboxyl groups in the structure of Gd@C82O42H32 were determined by infrared spectroscopy and confirmed by quantum chemical calculations. The groups were supposed to endow Gd@C82O42H32 with higher penetration ability through the cellular membrane, activation ability, lower toxicity, balancing of the ROS content in the bacterial suspensions, and lower aggregation in aqueous media.
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