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

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Каталог книг и брошюр библиотеки ИФ СО РАН (11)

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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Yaroslavtsev R. N., Tyumentseva A.V., Velikanov D. A., Vazhenina I. G., Volochaev M. N., Stolyar S. V.
Заглавие : Fe3O4/Au nanocomposites: Characterization and cytotoxicity effects in vitro
Колич.характеристики :8 с
Место публикации : Mater. Chem. Phys. - 2024. - Vol. 322. - Ст.129524. - ISSN 02540584 (ISSN), DOI 10.1016/j.matchemphys.2024.129524. - ISSN 18793312 (eISSN)
Примечания : Cited References: 44
Аннотация: Magnetic nanocomposites containing iron oxide and gold components take great attention last years because of their relative biocompatibility and the ability to combine the magnetic properties of iron and the chemical bonding properties of gold for the possible drug delivery or diagnostics for various diseases. However, such particles have some toxicity to living cells, and the effect depends on many factors, including size, shape, the ratio of components in the composites, and the type of cells affected. And thus, the search for compositions and technologies for producing iron-gold particles with improved properties and reduced cytotoxicity remains relevant. The aim of the study was to synthesize and characterize Fe3O4/Au nanocomposites and evaluate their influence on living cells using the example of cell line HEK293. Fe3O4 nanoparticles (NPs) were synthesized by co-precipitation of Fe2+/Fe3+ water solution in alkaline conditions and then boiled with HAuCl4 in 0.1 M sodium citrate. The NPs properties were estimated by transmission electron microscopy (TEM), vibration magnetometry and ferromagnetic resonance (FMR). According to magnetometric measurements, nanoparticles are mainly in a superparamagnetic state. By fitting magnetization curves, the magnetic characteristics of nanoparticles were determined: saturation magnetization (59.3 emu/g) and magnetic anisotropy constant (K = 0.86·105 erg/cm3). The average particle size estimated from magnetic measurements was 8.7 nm. Considering the presence of a magnetically dead layer, this is in good agreement with the TEM results. The temperature dependence of the FMR linewidth was analyzed using two models. As a result, the parameters MSV and K/MS were determined. The models used showed good agreement. The values of the anisotropy constant (K = 1.06·105 erg/cm3) and the average particle size (6.8 nm) are estimated. The effect of the NPs on the HEK293 cells was studied by MTT-assay, flow cytometry and RT-PCR. The exposure with the NPs lead to a significant decrease of cell metabolic activity in HEK293 cell culture, but this effect was not accompanied by cell death. It was shown that the expression of antioxidant enzymes SOD1 and GPX1 was reduced at the mRNA stage. So the NPs synthesized may affect gene expression and metabolism of HEK293 cells, but this does not have fatal consequences for cell viability.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Kirik N., Krylov A. S., Boronin A., Koshcheev S., Solovyov L., Rabchevskii E., Shishkina N., Anshits A.
Заглавие : The relationship between the structural characteristics of α-Fe2O3 catalysts and their lattice oxygen reactivity regarding hydrogen
Место публикации : Materials. - 2023. - Vol. 16, Is. 12: The 15th Anniversary of Materials — Recent Advances in Catalytic Materials. - Ст.4466. - ISSN 19961944 (eISSN), DOI 10.3390/ma16124466
Примечания : Cited References: 63. - This work was conducted within the framework of the budget project for the Institute of Chemistry and Chemical Technology of the Siberian Branch of the Russian Academy of Sciences, Federal Research Center KSC SB RAS, No. FWES–2021–0013
Аннотация: In this paper, the relationship between the structural features of hematite samples calcined in the interval of 800–1100 °C and their reactivity regarding hydrogen studied in the temperature-programmed reaction (TPR-H2) was studied. The oxygen reactivity of the samples decreases with the increasing calcination temperature. The study of calcined hematite samples used X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), and Raman spectroscopy, and their textural characteristics were studied also. According to XRD results, hematite samples calcined in the temperature range under study are monophase, represented by the α-Fe2O3 phase, in which crystal density increases with increasing calcination temperature. The Raman spectroscopy results also register only the α-Fe2O3 phase; the samples consist of large, well-crystallized particles with smaller particles on their surface, having a significantly lower degree of crystallinity, and their proportion decreases with increasing calcination temperature. XPS results show the α-Fe2O3 surface enriched with Fe2+ ions, whose proportion increases with increasing calcination temperature, which leads to an increase in the lattice oxygen binding energy and a decrease in the α-Fe2O3 reactivity regarding hydrogen.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Kicheeva A. G., Sushko E. S., Bondarenko L. S., Kydralieva K. A., Pankratov D. A., Tropskaya N. S., Dzeranov A. A., Dzhardimalieva G. I., Zarrelli M., Kudryasheva N. S.
Заглавие : Functionalized magnetite nanoparticles: Characterization, bioeffects, and role of reactive oxygen species in unicellular and enzymatic systems
Место публикации : Int. J. Mol. Sci. - 2023. - Vol. 24, Is. 2. - Ст.1133. - ISSN 16616596 (ISSN), DOI 10.3390/ijms24021133. - ISSN 14220067 (eISSN)
Примечания : Cited References: 125. - This research was funded by Russian Science Foundation, N 22-73-10222
Аннотация: The current study evaluates the role of reactive oxygen species (ROS) in bioeffects of magnetite nanoparticles (MNPs), such as bare (Fe3O4), humic acids (Fe3O4-HA), and 3-aminopropyltriethoxysilane (Fe3O4-APTES) modified MNPs. Mössbauer spectroscopy was used to identify the local surrounding for Fe atom/ions and the depth of modification for MNPs. It was found that the Fe3O4-HA MNPs contain the smallest, whereas the Fe3O4-APTES MNPs contain the largest amount of Fe2+ ions. Bioluminescent cellular and enzymatic assays were applied to monitor the toxicity and anti-(pro-)oxidant activity of MNPs. The contents of ROS were determined by a chemiluminescence luminol assay evaluating the correlations with toxicity/anti-(pro-)oxidant coefficients. Toxic effects of modified MNPs were found at higher concentrations (10−2 g/L); they were related to ROS storage in bacterial suspensions. MNPs stimulated ROS production by the bacteria in a wide concentration range (10−15–1 g/L). Under the conditions of model oxidative stress and higher concentrations of MNPs (10−4 g/L), the bacterial bioassay revealed prooxidant activity of all three MNP types, with corresponding decay of ROS content. Bioluminescence enzymatic assay did not show any sensitivity to MNPs, with negligible change in ROS content. The results clearly indicate that cell-membrane processes are responsible for the bioeffects and bacterial ROS generation, confirming the ferroptosis phenomenon based on iron-initiated cell-membrane lipid peroxidation.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Grossman, Victoria G., Molokeev M. S., Bazarov, Bair G., Bazarova, Jibzema G.
Заглавие : Synthesis and characterization of a new magnesium molybdates Tl1.85M0.15Mg2(MoO4)3 (M = K, Rb) with a langbeinite type structure
Место публикации : Solid State Sci. - 2023. - Vol. 142. - Ст.107249. - ISSN 12932558 (ISSN), DOI 10.1016/j.solidstatesciences.2023.107249. - ISSN 18733085 (eISSN)
Примечания : Cited References: 39. - This work was supported by the state order of BINM SB RAS (0273-2021-0008). Research was conducted using equipment of the CCU BINM SB RAS. Some experiments were obtained with use the analytical equipment of analytical equipment of Krasnoyarsk Regional Center of Research Equipment of Federal Research Center “Krasnoyarsk Science Center SB RAS”. M.S. Molokeev's work was carried out within the framework of the Strategic Academic Leadership Program “Priority-2030″ for the Siberian Federal University
Аннотация: In this work we have successfully synthesized pure phases of Tl1.85M0.15Mg2(MoO4)3 (M = K, Rb) langbeinite powders using the solid-state reaction method. Structural characterization was carried out via the Rietveld method on the X-ray powder diffraction data. The following unit cell parameters are calculated for Tl1.85K0.15Mg2(MoO4)3: a = 10.68509(16) A, V = 1219.93(6) A3, and for Tl1.85Rb0.15Mg2(MoO4)3: a = 10.69463(9) A, V = 1223.20(3) A3. The electrical conductivity was studied by impedance spectroscopy in the [473–1010 K] temperature range and results show that the Tl1.85M0.15Mg2(MoO4)3 (M = K, Rb) were ionic solid electrolyte conductors. Results also show that Tl1.85K0.15Mg2(MoO4)3 has the highest electrical conductivity.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Fomenko E. V., Akimochkina G. V., Knyazev Yu. V., Semenov S. V., Yumashev V. V., Solovyov L. A., Anshits A. G.
Заглавие : Characterization and magnetic properties of sintered glass-ceramics from dispersed fly ash microspheres
Место публикации : Magnetochemistry. - 2023. - Vol. 9, Is. 7. - Ст.177. - ISSN 23127481 (eISSN), DOI 10.3390/magnetochemistry9070177
Примечания : Cited References: 50. - Russian Science Foundation and the Krasnoyarsk Regional Science Foundation, grant number 22-27-20039, https://rscf.ru/project/22-27-20039/ (accessed on 15 March 2023)
Аннотация: The recycling of hazardous industrial waste into high-tech materials with desired properties is of considerable interest since it provides optimal alternatives for its final disposal. Coal fly ash, the major waste generated by coal-fired power plants, contains significant quantities of dispersed microspheres with a diameter smaller than 10 μm, which are anthropogenic atmospheric pollutants PM10. Due to their composition and fine-grained powder morphology, they can be converted into sintered products. In this study, dispersed microspheres from class C fly ash were directly sintered without any additive to form high-strength glass-ceramics with magnetic properties. The optimum processing conditions were achieved at a temperature of 1200 °C, at which samples with a compressive strength of 100.6 MPa were obtained. Sintering reduces the quantity of the glass phase and promotes the formation of larnite, Fe-spinel, ye’elimite, and ternesite. Mössbauer measurements show that the relative concentration of the magnetic phase compared to the paramagnetic one rises almost in order. The sintered sample demonstrates a narrower distribution of the hyperfine magnetic field and a significantly lower value of the coercive field of 25 Oe, which allows proposing such materials as soft magnetic materials. The presented results demonstrate promising industrial applications of hazardous PM10 to minimize solid waste pollution.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Komogortsev S. V., Vazhenina I. G., Kleshnina S. A., Iskhakov R. S., Lepalovskij V. N., Pasynkova A. A., Svalov A. V.
Заглавие : Advanced characterization of FeNi-based films for the development of magnetic field sensors with tailored functional parameters
Место публикации : Sensors. - 2022. - Vol. 22, Is. 9. - Ст.3324. - ISSN 14248220 (ISSN), DOI 10.3390/s22093324
Примечания : Cited References: 35. - This research was funded by the Russian Science Foundation (RSF), project no. 22-29-00980, https://rscf.ru/en/project/22-29-00980/ (accessed on 20 March 2022)
Аннотация: Magnetometry and ferromagnetic resonance are used to quantitatively study magnetic anisotropy with an easy axis both in the film plane and perpendicular to it. In the study of single-layer and multilayer permalloy films, it is demonstrated that these methods make it possible not only to investigate the average field of perpendicular and in-plane anisotropy, but also to characterize their inhomogeneity. It is shown that the quantitative data from direct integral and local measurements of magnetic anisotropy are consistent with the direct and indirect estimates based on processing of the magnetization curves. The possibility of estimating the perpendicular magnetic anisotropy constant from the width of stripe domains in a film in the transcritical state is demonstrated. The average in-plane magnetic anisotropy field of permalloy films prepared by magnetron sputtering onto a Corning glass is almost unchanged with the thickness of a single-layer film. The inhomogeneity of the perpendicular anisotropy field for a 500 nm film is greater than that for a 100 nm film, and for a multilayer film with a total permalloy thickness of 500 nm, it is greater than that for a homogeneous film of the same thickness.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Mikhlin Y. L., Borisov R. V., Vorobyev S. A., Tomashevich Y. V., Romanchenko A. S., Likhatski M. N., Karacharov A. A., Bayukov O. A., Knyazev Yu. V., Velikanov D. A., Zharkov S. M., Krylov A. S., Krylova S. N., Nemtsev I. V.
Заглавие : Synthesis and characterization of nanoscale composite particles formed by 2D layers of Cu-Fe sulfide and Mg-based hydroxide
Место публикации : J. Mater. Chem. A. - 2022. - Vol. 10, Is. 17. - P.9621-9634. - ISSN 20507488 (ISSN), DOI 10.1039/d2ta00877g
Примечания : Cited References: 84. - This research was supported by the Russian Foundation for Basic Research, Krasnoyarsk Territory Administration and Krasnoyarsk Territory Science Foundation, project 20-43-242903. Facilities of the Krasnoyarsk Regional Center of Research Equipment of Federal Research Center “Krasnoyarsk Science Center SB RAS” were employed in the work
Аннотация: We introduce here a multifunctional material composed of alternating atomic sulfide sheets close to the composition of CuFeS2 and Mg-based hydroxide ones (valleriite), which are assembled due to their electric charges of opposite sign. Valleriite particles 50-200 nm in lateral size and 10-20 nm in thickness were synthesized via a simple hydrothermal pathway using various concentrations of precursors and dopants, and examined with XRD, TEM, EDS, X-ray photoelectron spectroscopy, reflection electron energy loss spectroscopy (REELS), Mossbauer, Raman and UV-vis-NIR spectroscopies, and magnetization, dynamic light scattering, and zeta potential measurements. The electronic, magnetic and optical characteristics are found to be critically dependent on the charge (electron density) at the narrow-gap sulfide layers containing Cu+ and Fe3+ cations, and can be tuned via the composition of the hydroxide part. Particularly, substitution of Mg2+ with Al3+ increases the negative charge of the hydroxide layers and reduces the content of Fe3+-OH centers (10-45% of total iron); the effects of Cr and Co dopants entering both layers are more complicated. Mossbauer doublets of paramagnetic Fe3+ detected at room temperature transform into several Zeeman sextets at 4.2 K; the hyperfine fields up to 500 kOe and complex magnetic behavior, but not pure paramagnetism or antiferromagnetism, were observed for valleriites with the higher positive charge of the sulfide sheets, probably due to the depopulation of the minority-spin 3d states of S-bonded Fe3+ ions. Aqueous colloids of valleriite show optical absorption at 500-750 nm, which, along with the peaks at the same energies in REELS, may arise due to quasi-static dielectric resonance involving the vacant Fe 3d band and being dependent on the composition of both layers too. These and other findings call attention to valleriites as a new rich family of 2D materials for a variety of potential applications.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Cazacu, Nicoleta, Chilom, Claudia G., Iftimie, Sorina, Balasoiu, Maria, Ladygina, Valentina P., Stolyar S. V., Orelovich, Oleg L., Kovalev, Yuriy S., Rogachev, Andrey V.
Заглавие : Biogenic ferrihydrite nanoparticles produced by Klebsiella oxytoca: Characterization, physicochemical properties and bovine serum albumin interactions
Место публикации : Nanomaterials. - 2022. - Vol. 12, Is. 2. - Ст.249. - ISSN 2079-4991(eISSN), DOI 10.3390/nano12020249
Примечания : Cited References: 59. - This research was funded by JINR Themes 02-1-1107-2011/2021, 04-5-1131-2017/2021 and 04-4-1133-2018/2023 and with the financial support of the RO-JINR Projects Nos. 366/11.05.2021 (items 7, 86, 97) and 365/11.05.2021 (items 8, 87 and 98). This work also benefited from the use of the SasView application, originally developed under NSF Award DMR-0520547. SasView also contains the code developed with funding from the EU Horizon 2020 program under the SINE2020 project Grant No 654000. The APC was funded by JINR Theme 02-1-1107-2011/2021, Project No. 366/11.05.2021, item 7. This study used the infrastructure of the Applied Genetics Resource Facility of MIPT (Suport Grant 075-15-2021-684)
Предметные рубрики: MAGNETIC-PROPERTIES
REDUCTION
MOSSBAUER
FERRITIN
DOCKING
BINDING
Аннотация: The synthesis of nanoparticles inside microorganisms is an economical alternative to chemical and physical methods of nanoparticle synthesis. In this study, ferrihydrite nanoparticles synthesized by Klebsiella oxytoca bacterium in special conditions were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDS), small-angle X-ray (SAXS), UV-Vis spectroscopy, fluorescence, fluorescence resonance energy transfer (FRET), and molecular docking. The morphology and the structure of the particles were characterized by means of SEM and SAXS. The elemental content was determined by means of the EDS method. The absorption properties of the ferrihydrite nanoparticles were investigated by UV-Vis spectroscopy. The binding mechanism of the biogenic ferrihydrite nanoparticles to Bovine Serum Albumin (BSA) protein, studied by fluorescence, showed a static and weak process, combined with FRET. Protein denaturation by temperature and urea in the presence of the ferrihydrite nanoparticles demonstrated their influence on the unfolding process. The AutoDock Vina and UCSF Chimera programs were used to predict the optimal binding site of the ferrihydrite to BSA and to find the location of the hydrophobic cavities in the sub-domain IIA of the BSA structure.
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Вид документа : Статья из журнала
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Автор(ы) : Murueva A. V., Shershneva A. M., Nemtsev I. V., Shishatskaya E. I., Volova T. G.
Заглавие : Collagen conjugation to carboxyl-modified poly(3-hydroxybutyrate) microparticles: preparation, characterization and evaluation in vitro
Место публикации : J. Polym. Res. - 2022. - Vol. 29, Is. 8. - Ст.324. - ISSN 10229760 (ISSN), DOI 10.1007/s10965-022-03181-5
Примечания : Cited References: 45. - This work was supported by the State Assignment of the Ministry of Science and Higher Education of the Russian Federation No. FSRZ-2020–0006
Аннотация: The objective of this study was to produce and characterize collagen conjugated poly(3-hydroxybutyrate) (P3HB) microparticles. The double emulsion solvent evaporation technique was used to fabricate biopolymer microparticles. Alkaline hydrolysis method was used for carboxylation of P3HB microparticles followed by collagen (type I) conjugation using 1-ethyl-3-(3-dime-thylaminopropyl) carbodiimide and N-hydroxysuccinimide cross linkers. The successful chemical modification of P3HB-MP surface was evidenced by XPS analysis and FTIR spectroscopy, confirming an increase in the number of carboxyl groups and covalent bonding of collagen on the surface of functionalized P3HB microparticles (Col-P3HB-MPs). The amount of collagen present on Col-P3HB-MPs microparticles was quantified by the Lowry method. The average diameter and zeta-potential of microparticles were found to be dependent upon the method of preparation. The absence of cytotoxicity of modified Col-P3HB-MPs to fibroblast NIH 3T3 cells in vitro was corroborated by results of MTT assay. Staining with the fluorescent dye showed enhanced adhesion of fibroblasts onto Col-P3HB-MPs compared to the unmodified P3HB-MPs.
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10.

Вид документа : Статья из сборника (однотомник)
Шифр издания :
Автор(ы) : Rautskii M. V., Yakovlev I. A., Tarasov A. S., Bondarev M. A.
Заглавие : Synthesis and characterization of epitaxial Mn5Ge3 thin films on a silicon substrate
Коллективы : Российская академия наук, Физико-технический институт им. Е.К. Завойского ФИЦ Казанского научного центра РАН, Казанский (Приволжский) федеральный университет, Euro-Asian Symposium "Trends in MAGnetism", "Trends in MAGnetism", Euro-Asian Symposium
Место публикации : VIII Euro-Asian symposium "Trends in magnetism" (EASTMAG-2022): Book of abstracts/ program com. S. G. Ovchinnikov [et al.]. - 2022. - Vol. 1, Sect.: Spin dynamics and magnetic resonances. - Ст.B.P2. - P.266-268. - ISBN 978-5-94469-051-7
Примечания : Cited References: 2. - Support by Russian Foundation for Basic Research, the Government of the Krasnoyarsk Territory, and the Krasnoyarsk Territorial Foundation for Support of Scientific and R&D Activities, (project no. 20-42-243007) and support by Krasnoyarsk Regional Fund of Science is acknowledged
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11.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Mikhlin Y. L., Likhatski M. N., Romanchenko A. S., Vorobyev S. A., Tomashevich Y. V., Fetisova O. Yu., Bayukov O. A., Knyazev Yu. V., Nemtsev I. V., Karasev S. V., Karacharov A. A., Borisov R. V.
Заглавие : Valleriite-containing ore from Kingash deposit (Siberia, Russia): Mossbauer and X-ray photoelectron spectroscopy characterization, thermal and interfacial properties
Место публикации : J. Sib. Fed. Univ. Chem. - 2022. - Vol. 15, Is. 3. - P.303-317. - ISSN 19982836 (ISSN), DOI 10.17516/1998-2836-0294; Журн. СФУ. Химия
Примечания : Cited References: 25. - This research was funded by the Russian Foundation for Basic Research, Krasnoyarsk Territory Science Foundation and Krasnoyarsk Territory Administration, grant number 20-43-242903. Facilities of the Krasnoyarsk Regional Center of Research Equipment of Federal Research Center «Krasnoyarsk Science Center SB RAS» were employed in the work
Аннотация: Valleriite, (Cu,Fe)S2×n(Mg,Al,Fe)(OH)2, and related layered minerals are of interest due to their unusual two-dimensional structure, formation mechanisms, physical and chemical properties, and potential involvement into mineral processing and materials science applications. Here, we have studied Kingash Cu-Ni ore samples containing 10-25% of valleriite in association with serpentines (lizardite and chrysotile) and magnetite using scanning electron microscopy and electron microprobe analysis, Mössbauer spectroscopy, X-ray photoelectron spectroscopy (XPS), thermal analysis and zeta potential measurement. The data are compared with those for Al-doped valleriite synthesized via a hydrothermal route. It was found that the Kingash valleriite contains excessive iron relative to CuFeS2 stoichiometry, which mainly occurs, leaving aside magnetite, as Fe3+-OH species in hydroxide layers of valleriite and minor Fe centers in serpentines. Thermal dehydroxylation of hydroxide layers of valleriites occurs near 500oC in inert atmosphere; in air, sulfide sheets oxidize with an exothermal peak at 447oC, and sulfur oxides don't volatilize but react with hydroxide groups of valleriite rather than serpentines. Zeta potential measurements of coarse ore particles using the flow potential technique suggested that the surface of valleriite is negatively charged in a wide pH range while the positive values at low pHs for fine particles are inflicted by serpentine. The findings demonstrate close resemblance of the natural and synthetic Al-doped valleriites, and the key role of valleriite, despite its moderate content, for the interfacial characteristics of the valleriite-bearing ores.Валлериит, (Cu, Fe)S2×n(Mg, Al, Fe)(OH)2 и родственные ему слоистые минералы представляют интерес в связи с их необычной двумерной структурой, механизмами образования, физическими и химическими свойствами и возможностью применения в процессах переработки полезных ископаемых и материаловедения. В настоящей работе с помощью сканирующей электронной микроскопии и электронного микрозондового анализа, мессбауэровской спектроскопии, рентгеновской фотоэлектронной спектроскопии (РФЭС), термического анализа и измерения дзета-потенциала нами были изучены образцы медно-никелевых руд Кингашского месторождения, содержащие 10–25 % валлериита в ассоциации с серпентинами (лизардит и хризотил) и магнетитом. Было проведено сравнение полученных данных с результатами измерений легированного алюминием валлериита, синтезированного гидротермальным способом. Установлено, что валлериит Кингашского месторождения содержит избыточное железо по отношению к стехиометрии CuFeS2, которое представлено в основном, не считая магнетита, в виде центров Fe3+-OH, расположенных в гидроксидных слоях валлериита и небольшого числа примесей Fe в серпентинах. Термическое дигидроксилирование гидроксидных слоев валлериитов происходит около 500 °C в инертной атмосфере; на воздухе сульфидные слои окисляются с экзотермическим пиком при 447 °C, а оксиды серы не улетучиваются, а реагируют скорее с гидроксидными группами валлериита, чем с серпентинами. Измерения дзета-потенциала крупных частиц руды с использованием метода потенциала протекания показали, что поверхность валлериита отрицательно заряжена в широком диапазоне рН, в то время как положительные показатели при низких значениях рН для более мелких частиц обусловлены присутствием серпентина. Полученные данные демонстрируют близкое сходство природного и синтетического валлериитов, легированного алюминием, и его ключевую роль для межфазных характеристик валлериитсодержащих руд, даже при его умеренном содержании.
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12.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Myagkov V. G., Bykova L. E., Zhigalov V. S., Kokh D., Mikhlin Y. L., Matsynin A. A., Bondarenko G. N.
Заглавие : Solid-state synthesis, structural and magnetic characterization of ferromagnetic phases in 24Ga/76Fe(0 0 1), 40Ga/60Fe(0 0 1) and 60Ga/40Fe(0 0 1) bilayers
Место публикации : J. Magn. Magn. Mater. - 2022. - Vol. 561. - Ст.169709. - ISSN 03048853 (ISSN), DOI 10.1016/j.jmmm.2022.169709
Примечания : Cited References: 77. - The work is partially based upon the experiments performed on Krasnoyarsk Regional Center of Research Equipment of Federal Research Center «Krasnoyarsk Science Center SB RAS»
Аннотация: The A2, B2, D03 phases and dispersive nanoprecipitates play key roles in the nature of super-functional properties, such as the large and sensitive magnetostriction, in Fe100-xGax alloys. However, the temperature conditions for the occurrence of the chemical interaction between Fe and Ga, leading to the synthesis of these phases and nanoprecipitates, remain completely unexplored. Herein we first report results of the start of the chemical interaction at the Ga/Fe(0 0 1) interface and the structural and magnetic phase transformations in 24Ga/76Fe(0 0 1), 40Ga/60Fe(0 0 1) and 60Ga/40Fe(0 0 1) bilayers from room temperature to 800 °C. For all bilayers the magnetic ordered D03 phase is the first phase which is formed at the Ga/Fe(0 0 1) interface at ∼ 375 °C. When the annealing temperature is increased above 580 °C in 24Ga/76Fe(0 0 1) samples the epitaxial D03(0 0 1) layer begins to develop into the epitaxial magnetic ordered B2(0 0 1) layer, which remains after annealing to 800 °C. In 40Ga/60Fe(0 0 1) samples the epitaxial D03(0 0 1) layer evolves into the epitaxial B2(0 0 1) layer and a new epitaxial layer with interplanar spacing 0.1484 nm (L60ʹ), which has close reflections with L60 nanoprecipitates. The L60ʹ phase exhibits unique magnetic properties, including a large magnetic fourfold anisotropy constant of ∼ 7·105 erg/cm3 and 8-fold anisotropy. The solid-state reactions in 60Ga/40Fe(0 0 1) samples start with the synthesis of D03 nanograins embedded in amorphous phases, whose peaks are centered on D03(0 0 4) and Fe(0 0 2) reflections. Above 700 °C the amorphous phases partially crystallize and the epitaxial magnetic L60ʹ and ordered B2(0 0 1) phases emerge. Dewetting and unidentified secondary precipitations are observed in all samples and their influence on the magnetic properties is discussed. Our results demonstrate not only the complex nature of initial stage Fe100-xGax alloy synthesis, but also predict the low-temperature transformation at ∼ 375 °C in the Fe - Ga phase diagram.
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13.

Вид документа : Статья из журнала
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Автор(ы) : Mikhlin Y. L., Likhatski M. N., Bayukov O. A., Knyazev Yu. V., Velikanov D. A., Tomashevich Y. V., Romanchenko A. S., Vorobyev S. A., Volochaev M. N., Zharkov S. M., Meira D. M.
Заглавие : Valleriite, a natural two-dimensional composite: X-ray absorption, photoelectron, and Mossbauer spectroscopy, and magnetic characterization
Место публикации : ACS Omega. - 2021. - Vol. 6, Is. 11. - P.7533-7543. - ISSN 24701343 (ISSN), DOI 10.1021/acsomega.0c06052
Примечания : Cited References: 92. - This research was supported by the Russian Science Foundation, project 18-17-00135. The authors thank Dr. Y. Laptev for providing valleriite samples, the ESRF for allocating beamtime and the BM23 staff for their help during the experiments. Facilities of the Krasnoyarsk Regional Research Equipment Centre of SB RAS were employed in the work
Аннотация: Valleriite is of interest as a mineral source of basic and precious metals and as an unusual material composed of two-dimensional (2D) Fe-Cu sulfide and magnesium hydroxide layers, whose characteristics are still very poorly understood. Here, the mineral samples of two types with about 50% of valleriites from Noril'sk ore provenance, Russia, were examined using Cu K- and Fe K-edge X-ray absorption fine structure (XAFS) spectroscopy, X-ray photoelectron spectroscopy (XPS), 57Fe Mossbauer spectroscopy, and magnetic measurements. The Cu K X-ray absorption near-edge structures (XANES) spectra resemble those of chalcopyrite, however, with a higher electron density at Cu+ centers and essentially differ from those of bornite Cu5FeS4; the Fe K-edge was less informative because of accompanying oxidized Fe-containing phases. The post-edge XANES and extended XAFS (EXAFS) analysis reveal differences in the bond lengths, e.g., additional metal-metal distances in valleriites as compared with chalcopyrite. The XPS spectra confirmed the Cu+ and Fe3+ state in the sulfide sheets and suggest that they are in electron equilibrium with (Mg, Al) hydroxide layers. Mossbauer spectra measured at room temperature comprise central doublets of paramagnetic Fe3+, which decreased at 78 K and almost disappeared at 4.2 K, producing a series of hyperfine Zeeman sextets due to internal magnetic fields arising in valleriites. Magnetic measurements do not reveal antiferromagnetic transitions known for bornite. The specific structure and properties of valleriite are discussed in particular as a platform for composites of the 2D transition metal sulfide and hydroxide (mono)layers stacked by the electrical charges, promising for a variety of applications.
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14.

Вид документа : Статья из журнала
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Автор(ы) : Saikova S., Pavlikov A., Trofimova T., Mikhlin Y., Karpov D., Asanova A., Grigoriev Y., Volochaev M. N., Samoilo A., Zharkov S. M., Velikanov D. A.
Заглавие : Hybrid nanoparticles based on cobalt ferrite and gold: Preparation and characterization
Место публикации : Metals. - 2021. - Vol. 11, Is. 5. - Ст.705. - ISSN 20754701 (ISSN), DOI 10.3390/met11050705
Примечания : Cited References: 74
Аннотация: During the past few decades, hybrid nanoparticles (HNPs) based on a magnetic material and gold have attracted interest for applications in catalysis, diagnostics and nanomedicine. In this paper, magnetic CoFe2O4/Au HNPs with an average particle size of 20 nm, decorated with 2 nm gold clusters, were prepared using methionine as a reducer and an anchor between CoFe2O4 and gold. The methionine was used to grow the Au clusters to a solid gold shell (up to 10 gold deposition cycles). The obtained nanoparticles (NPs) were studied by X-Ray diffraction (XRD), transmis-sion electron microscopy (TEM), Fourier-transform infrared (FT-IR) spectroscopy, X-Ray photoelectron spectroscopy (XPS) and UV-vis spectroscopy techniques. The TEM images of the obtained HNPs showed that the surface of cobalt ferrite was covered with gold nanoclusters, the size of which slightly increased with an increase in the number of gold deposition cycles (from 2.12 ± 0.15 nm after 1 cycle to 2.46 ± 0.13 nm after 10 cycles). The density of the Au clusters on the cobalt ferrite surface insignificantly decreased during repeated stages of gold deposition: 21.4 ± 2.7 Au NPs/CoFe2O4 NP after 1 cycle, 19.0 ± 1.2 after 6 cycles and 18.0 ± 1.4 after 10 cycles. The magnetic measurements showed that the obtained HNPs possessed typical ferrimagnetic behavior, which corresponds to that of CoFe2O4 nanoparticles. The toxicity evaluation of the synthesized HNPs on Chlorella vulgaris indicated that they can be applied to biomedical applications such as magnetic hyperthermia, photothermal therapy, drug delivery, bioimaging and biosensing.
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15.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Myagkov V. G., Bykova L. E., Zhigalov V. S., Matsynin A. A., Velikanov D. A., Bondarenko G. N.
Заглавие : Solid-state synthesis, rotatable magnetic anisotropy and characterization of Co1-xPtx phases in 50Pt/50fccCo(001) and 32Pt/68fccCo(001) thin films
Место публикации : J. Alloys Compd. - 2021. - Vol. 861. - Ст.157938. - ISSN 09258388 (ISSN), DOI 10.1016/j.jallcom.2020.157938
Примечания : Cited References: 80. - This study was supported by the Russian Foundation for Basic Research , Government of Krasnoyarsk Territory, Krasnoyarsk Regional Fund of Science for the research projects no. 19-43-240003. The authors thank I.V. Nemtsev for assisting with the measurements of the samples’ composition. The work is partially based upon the experiments performed at Krasnoyarsk Regional Center of Research Equipment of Federal Research Center «Krasnoyarsk Science Center SB RAS»
Аннотация: We reported the phase formation sequences in 50Pt/50fcc-Co(001) and 32Pt/68fcc-Co(001) thin films after annealing up to 850 °C. In both cases, the ordered L10 phase formed first on the Pt/Co interface at ∼400 °C and as the annealing temperature increased the L10 phase transformed into the chemically disordered fcc A1 phase in 50Pt/50fcc-Co(001) at 750 °C and in 32Pt/68fcc-Co(001) films at 550 °C. Based on the analysis of solid-state reactions in thin films, a phase transition at ∼ 400 °C is predicted in Co-Pt systems with a 32–72% Pt composition. Torque measurements of the 50Pt/50fcc-Co(001) samples showed that the rotatable magnetic anisotropy coexisted with the three variants of L10 in a temperature range of 400–750 °C. An analysis of the torque curves revealed that the L10 films consist of a soft magnetic layer epitaxially intergrown to the substrate MgO(001) and a top layer having rotatable magnetic anisotropy. It showed that the magnetically hard properties of L10 films are associated with a rotatable magnetic anisotropy layer. A model of rotatable magnetic anisotropy is reasoned, which is founded on some identical mechanisms of rotatable magnetic anisotropy and magnetic-field-induced strains, explaining the ferromagnetic shape-memory effect in Heusler alloys. Our results suggested that the rotatable magnetic anisotropy phenomena may have an important role in the origin of perpendicular anisotropy in hard magnetic L10 structures.
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16.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Киселев, Евгений Геннадьевич, Васильев, Александр Дмитриевич, Волова Т. Г.
Заглавие : Синтез и характеристики многокомпонентных ПГА
Место публикации : Журн. СФУ. Биология. - 2021. - Т. 14, № 1. - С. 97-113. - ISSN 1997-1389 (ISSN), DOI 10.17516/1997-1389-0325; J. Sib. Fed. Univ. Biol. - ISSN 2313-5530 (eISSN)
Примечания : Библиогр.: 32. - Работа выполнена по гранту No 19-43-240012 «Биологические и физические принципы получения биоматериалов новой генерации» при поддержке РФФИ и ККФН и госзаданию Министерства науки и высшего образования РФ No FSRZ-2020-0006. В работе использовано оборудование Центра коллективного пользования приборами ФИЦ «КНЦ СО РАН»
Аннотация: В культуре бактерий Cupriavidus necator B10646 в режиме синтеза резервных полигидроксиалканоатов при включении в состав ростовой среды, помимо основного субстрата, глюкозы, субстратов-предшественников различных мономеров монокарбоновых кислот – солей валериановой и гексановой кислот, пропионата, γ-бутиролактона, синтезировано семейство трех- и четырехкомпонентных полимеров с различным набором и соотношением мономеров и исследованы физико-химические свойства. Трехкомпонентные образцы были образованы мономерами 3-гидроксибутирата (3ГБ), 3-гидроксивалерата (3ГВ), 4-гидроксибутирата (4ГБ) или 3-гидроксигексаноата (3ГГ) и имели следующие составы: П(3ГБ/3ГВ/4ГБ) и П(3ГБ/3ГВ/4ГГ); четырехкомпонентные сополимеры имели состав П(3ГБ/3ГВ/4ГБ/3ГГ). Все сополимерные образцы, независимо от состава и соотношения мономеров, обладали сниженными значениями молекулярной массы и повышенными значениями полидисперсности по сравнению с высококристалличным гомополимером 3-гидроксибутирата, но сохраняли свойства термостабильности, имея разрыв между температурой плавления и термической деградации не менее 100-110 °С. Включение в С-цепь 3ГБ мономеров 3ГВ, 4ГБ и 3ГГ вызывало значительные изменения соотношения кристаллической и аморфной фаз и снижение степени кристалличности (Сх), зависящие от типа мономеров и их содержания в сополимере. Максимальное снижение Сх (до 9-17 %) зарегистрировано у трехкомпонентных образцов П(3ГБ/3ГВ/4ГБ), у четырехкомпонентных сополимеров П(3ГБ/3ГВ/4ГБ/3ГГ) – до 30-36 %. Доказана возможность синтеза полимеров разного, в том числе нового, состава, существенно различающихся базовыми свойствами.Cupriavidus necator B10646 bacterial cells were cultivated in the mode of synthesis of the reserve polyhydroxyalkanoates (PHAs) in the growth medium that contained, in addition to glucose as the main substrate, precursor substrates of the monomers of various monocarboxylic acids – salts of valeric and hexanoic acids, propionate, and γ-butyrolactone. PHA terpolymers and quaterpolymers with different compositions and proportions of monomers were synthesized, and their physicochemical properties were studied. The terpolymers were composed of monomers of 3-hydroxybutyrate (3HB), 3-hydroxyvalerate (3HV), 4-hydroxybutyrate (4HB), or 3-hydroxyhexanoate (3HHx) and had the following compositions: P(3HB/3HB/4HHx) and P(3HB/3HV/4HHx). The quaterpolymers had the following composition: P(3HB/3HV/4HB/3HHx). All copolymer samples, regardless of the composition and proportions of monomers, had lower molecular weights and higher polydispersity values compared to the highly crystalline 3-hydroxybutyrate homopolymer, but retained thermal stability properties, with a difference between the melting point and thermal degradation of at least 100-110 °С. The inclusion of 3HV, 4HB, and 3HHx monomers in the C-chain of 3HB caused changes in the crystalline to amorphous phase ratio and a significant decrease in the degree of crystallinity (Cx), which depended on the type of monomers and their contents in the copolymer. The maximum decrease in Cx (9-17 %) was detected in the P(3HB/3HV/4HB) terpolymer and the P(3HB/3HV/4HB/3HHx) quaterpolymer (30-36 %). The study confirms that there is the possibility of synthesizing polymers with various compositions, including new ones, which differ significantly in their basic properties.
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17.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Muzalevskiy K. V., Karavaysky A. Yu.
Заглавие : Shielded open-circuited probe for in-situ measurements of soil permittivity in Very high frequency (VHF) and Ultra high frequency (UHF) bands
Коллективы : SB RAS project [0287-2021-0034]
Место публикации : Trans. Inst. Meas. Control. - 2021. - Vol. 43, Is. 16. - P.3566-3572. - ISSN 0142-3312, DOI 10.1177/01423312211037791. - ISSN 1477-0369(eISSN)
Примечания : Cited References: 30. - The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the SB RAS project No. 0287-2021-0034
Предметные рубрики: DIELECTRIC CHARACTERIZATION
MOISTURE
Аннотация: In this paper, the shielded open-circuited probe operating in the wide frequency range from 75MHz to 2GHz is proposed. The probe is made of an SubMiniature version A (SMA) flange connector. The central rod of the SMA connector emerges from a coaxial transition in the flange and shielded by four rods. The robe design allows us to calculate of the probe reflection coefficient S11 used simple analytical transmission line model (TEM wave mode), the parameters of which were calibrated on a set of substances with a known frequency spectrum of permittivity. The refractive index (RI) and normalized attenuation coefficient (NAC) retrieval technique is based on solving the inverse problem of minimizing the residual norm between measured and calculated frequency spectra of reflection coefficient S11. After calibration, the root-mean-square error (determination coefficient) between the measured and calculated module and phase of the reflection coefficient S11 for the sets of calibration media air, distilled water, butanol, pure ice, water solution with NaCl of salinity of 8.9% do not exceed 0.26dB (0.995) and 0.03 rad (0.999), respectively, in the frequency range from 75MHz to 2GHz. The root-mean-square error (determination coefficient) between the measured RI and NAC spectra for four soil cover samples (variation of the clay fraction from 10.5 g/g to 47.6 g/g) using the proposed probe and a precision coaxial cell not exceeds 0.109 (0.993) and 0.057 (0.986), respectively, in the frequency range from 75 MHz to 2 GHz. As a result, it is experimentally shown that RI и NAC can be measured by the proposed non-precision probe with an error comparable to the precision coaxial cell.
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18.

Вид документа : Статья из журнала
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Автор(ы) : Sobolev, Kirill, Pazniak, Hanna, Farle M., Rodionova, Valeria, Wiedwald, Ulf
Заглавие : Synthesis, phase purification and magnetic characterization of the (Cr1−x, Mnx)2AlC MAX-phase
Коллективы : Deutsche Forschungsgemeinschaft (DFG)German Research Foundation (DFG) [CRC/TRR 270, 405553726]; German-Russian Interdisciplinary Science Center (G-RISC); 5 top 100 Academic Excellence Project of the Russian Ministry of Science and Higher Education; government of the Russian Federation [075-15-2019-1886]
Место публикации : J. Mater. Chem. C. - 2021. - Vol. 9, Is. 46. - P.16516-16522. - ISSN 2050-7526, DOI 10.1039/d1tc03092b. - ISSN 2050-7534(eISSN)
Примечания : Cited References: 36. - This work was supported by the Deutsche Forschungsgemeinschaft (DFG) within CRC/TRR 270, project B02 (Project-ID 405553726). K. S. acknowledges German-Russian Interdisciplinary Science Center (G-RISC) for the provided mobility grant that supported the present work. K. S. also acknowledges 5 top 100 Academic Excellence Project of the Russian Ministry of Science and Higher Education for the provided financial support. M. F. acknowledges co-funding by the government of the Russian Federation (agreement No. 075-15-2019-1886)
Аннотация: The Cr2AlC MAX phase is a promising parent compound to introduce magnetism to nano-laminated ternary carbides by doping with Mn. Here, we demonstrate that Mn doping of bulk Cr2AlC powder synthesized by arc melting results in incorporation up to 16 at% Mn in the M-layers of the MAX phase. Simultaneously, the relative amount of secondary phases is overall low, however, increases with Mn doping. We successfully applied chemical treatment in dilute hydrochloric acid to eliminate secondary phases and studied the magnetic properties before and after treatment by magnetometry between 3 K and 800 K. All MAX-phases show a paramagnetic response.
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19.

Вид документа : Статья из журнала
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Автор(ы) : Myagkov V. G., Zhigalov V. S., Bykova L. E., Solovyov L. A., Matsynin A. A., Balashov Yu. Yu., Nemtsev I. V., Shabanov A. V., Bondarenko G. N.
Заглавие : Solid-state synthesis, dewetting, and magnetic and structural characterization of interfacial FexSn1−x layers in Sn/Fe(001) thin films
Место публикации : J. Mater. Res. - 2021. - Vol. 36, Is. 15. - P.3121-3133. - ISSN 08842914 (ISSN), DOI 10.1557/s43578-021-00312-4
Примечания : Cited References: 43. - This work was supported by the Russian Foundation for Basic Research together with the Government of the Krasnoyarsk Territory, the Krasnoyarsk Regional Fund of Science (Grant #19-43-240003). The work is partially based upon the experiments performed on Krasnoyarsk Regional Center of Research Equipment of Federal Research Center «Krasnoyarsk Science Center SB RAS»
Аннотация: The phase formation sequences in 9Sn/91Fe(001) and 25Sn/75Fe(001) bilayers during thin-film solid-state reactions up to 800°C were investigated using X-ray diffraction, the torque method, and scanning electron microscopy. In both samples, FeSn2, FeSn, α-Fe1−xSnx, Fe5Sn3, α-Fe, and β-Sn were sequentially formed at the initiation temperatures Tini ~ 150°C, ~ 300°C, ~ 550°C, ~ 600°C, and ~ 700°C, respectively. Low-temperature transformations were predicted at temperatures TK1 ~ 150°C and TK2 ~ 300°C, which are absent in the phase equilibrium diagram of the Fe–Sn system. Solid-state dewetting of the 9Sn/91Fe(001) and 25Sn/75Fe(001) bilayers started at temperatures above 550°C. Overall, this work sheds new light on general chemical mechanisms governing the synthesis of intermetallic phases in Sn/Fe(001) thin films, the phase transformations, and the evolution of the dewetting process of FexSn1−x films.
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20.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Shtarev, Dmitry S., Shtareva, Anna, V, Kevorkyants, Ruslan, Molokeev M. S., Serpone, Nick
Заглавие : Revisiting the BaBiO3 semiconductor photocatalyst: synthesis, characterization, electronic structure, and photocatalytic activity
Коллективы : Russian Science FoundationRussian Science Foundation (RSF) [19-73-10013]
Место публикации : Photochem. Photobiol. Sci. - 2021. - Vol. 20, Is. 9. - P.1147-1160. - ISSN 1474-905X, DOI 10.1007/s43630-021-00086-y. - ISSN 1474-9092(eISSN)
Примечания : Cited References: 48. - We wish to thank the Russian Science Foundation for a Grant (Project No. 19-73-10013) in support of our study. The authors are also grateful to the staff of the following Institutes/Centers for their valuable technical assistance and in providing the needed equipment: (i) the Khabarovsk Innovation and Analytical Center of the Yu. A. Kosygin Institute of Tectonics and Geophysics FEB RAS; and (ii) the Resource Centers of the Research Park at Saint-Petersburg State University, especially the Center for Physical Methods of Surface Investigation and the Nanophotonics Center. One of us (NS) is grateful to the staff of the PhotoGreen Laboratory of the University of Pavia, Italy, for their continued hospitality
Предметные рубрики: RHODAMINE-B
OXIDE
DRIVEN
SUPERCONDUCTIVITY
PSEUDOPOTENTIALS
Аннотация: This article revisits the properties of BaBiO3 examined extensively in the last two decades because of its electronic properties as a superconductor and as a semiconductor photocatalyst. Solid-state syntheses of this bismuthate have often involved BaCO3 as the barium source, which may lead to the formation of BaBiO3/BaCO3 heterostructures that could have an impact on the electronic properties and, more importantly, on the photocatalytic activity of this bismuthate. Accordingly, we synthesized BaBiO3 by a solid-state route to avoid the use of a carbonate; it was characterized by XRD, SEM, and EDX, while elemental mapping characterized the composition and the morphology of the crystalline BaBiO3 and its thin films with respect to structure, optoelectronic, and photocatalytic properties. XPS, periodic DFT calculations, and electrochemical impedance spectroscopy ascertained the electronic and electrical properties, while Raman and DRS spectroscopies assessed the relevant optical properties. The photocatalytic activity was determined via the degradation of phenol in aqueous media. Although some results accorded with earlier studies, the newer electronic structural data on this bismuthate, together with the photocatalytic experiments carried out in the presence of selective radical trapping agents, led to elucidating some of the mechanistic details of the photocatalytic processes that previous views of the BaBiO3 band structure failed to address or clarify. Analytical refinement of the XRD data inferred the as-synthesized BaBiO3 adopted the C2/m symmetry rather than the I2/m structure reported earlier, while Tauc plots from DRS spectra yielded a bandgap of 2.05 eV versus the range of 1.1–2.25 eV reported by others; the corresponding flatband potentials were 1.61 eV (EVB) and − 0.44 eV (ECB). The photocatalytic activity of BaBiO3 was somewhat greater than that of the well-known Evonik P25 TiO2 photocatalyst under comparable experimental conditions.
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