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1.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Andriushin N. D., Sukhanov A. S., Korshunov A. N., Pavlovskii M. S., Rahn M. C., Nikitin S. E.
Заглавие : Phonon topology and winding of spectral weight in graphite
Колич.характеристики :6 с
Место публикации : Phys. Rev. Lett. - 2023. - Vol. 131, Is. 24. - Ст.246601. - ISSN 00319007 (ISSN), DOI 10.1103/PhysRevLett.131.246601. - ISSN 10797114 (eISSN)
Примечания : Cited References: 42. - We thank R. Coldea for stimulating discussions. A. Bosak participated in the discussion and preparation of the experiment. We acknowledge financial support from the Swiss National Science Foundation, from the European Research Council under the grant Hyper Quantum Criticality (HyperQC), the German Research Foundation (DFG) through the Collaborative Research Center SFB 1143 (Project No. 247310070), and from the European Union Horizon 2020 research and innovation program under Marie Skłodowska-Curie Grant No. 884104. We acknowledge the European Synchrotron Radiation Facility (ESRF) for provision of synchrotron radiation facilities
Аннотация: The topology of electronic and phonon band structures of graphene is well studied and known to exhibit a Dirac cone at the K point of the Brillouin zone. Here, we applied inelastic x-ray scattering (IXS) along with ab initio calculations to investigate phonon topology in graphite, the 3D analog of graphene. We identified a pair of modes that form a very weakly gapped linear anticrossing at the K point that can be essentially viewed as a Dirac cone approximant. The IXS intensity in the vicinity of the quasi-Dirac point reveals a harmonic modulation of the phonon spectral weight above and below the Dirac energy, which was previously proposed as an experimental fingerprint of the nontrivial topology. We illustrate how the topological winding of IXS intensity can be understood in terms of atomic displacements and highlight that the intensity winding is not in fact sensitive in telling quasi- and true Dirac points apart.
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2.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Stolyar S. V., Chekanova L. A., Cheremiskina E. V., Yaroslavtsev R. N., Taran O. P., Borovkova V. S., Malyar Y. N., Neznakhin D. S., Komogortsev S. V.
Заглавие : Synthesis of transition metal coatings using arabinogalactan
Место публикации : Bull. Russ. Acad. Sci. Phys. - 2022. - Vol. 86, Is. 5. - P.597-600. - ISSN 10628738 (ISSN), DOI 10.3103/S1062873822050264
Примечания : Cited References: 19. - The study was supported by the Russian Foundation for Basic Research, the Government of the Krasnoyarsk Territory, and the Krasnoyarsk Regional Science Foundation (project no. 20-43-240003)
Аннотация: Carbon-containing transition metal (Fe, Co, Ni) coatings are synthesized via chemical deposition with arabinogalactan. The crystal structure and chemical composition of the coatings are determined. Data from magnetometry and X-ray diffraction show that carbon is not included in the crystal lattice of a metal. Instead, it exists in the form of graphite inclusions. Degradation of arabinogalactan in an alkaline medium on the surface of a galvanic pair is investigated.
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3.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Baek, Woohyeon, Gromilov, Serey A., Kuklin, Artem, V, Kovaleva, Evgenia A., Fedorov A. S., Sukhikh, Alexander S., Hanfland, Michael, Pomogaev, Vladimir A., Melchakova, Iuliia A., Avramov P. V., Yusenko, Kirill, V
Заглавие : Unique Nanomechanical Properties of Diamond-Lonsdaleite Biphases: Combined Experimental and Theoretical Consideration of Popigai Impact Diamonds
Место публикации : Nano Lett. - 2019. - Vol. 19, Is. 3. - P.1570-1576. - ISSN 1530-6984, DOI 10.1021/acs.nanolett.8b04421. - ISSN 1530-6992(eISSN)
Примечания : Cited References: 38. - The authors thank Dr. Valentin Afanasiev (Sobolev Institute of Geology and Mineralogy, Novosibirsk, Russia) for giving us access to a representative set of impact diamonds from Popigai astrobleme. The authors also acknowledge ID-15B beamline at the European Synchrotron Radiation Facility (ESRF) for providing measurement times and technical support. Dr. Valerio Cerantola (ESRF) is thanked for his kind support with the laser-heating setup. W.B., A.V.K., and P.V.A. acknowledge the National Research Foundation of Republic of Korea for support under grant no. NRF-2017R1A2B4001410.
Предметные рубрики: CARBON
PRESSURES
GRAPHITE
HARDNESS
ORIGIN
Аннотация: For the first time, lonsdaleite-rich impact diamonds from one of the largest Popigai impact crater (Northern Siberia) with a high concentration of structural defects are investigated under hydrostatic compression up to 25 GPa. It is found that, depending on the nature of a sample, the bulk modulus for lonsdaleite experimentally obtained by X-ray diffraction in diamond-anvil cells is systematically lower and equal to 93.3–100.5% of the average values of the bulk moduli of a diamond matrix. Density functional theory calculations reveal possible coexistence of a number of diamond/lonsdaleite and twin diamond biphases. Among the different mutual configurations, separate inclusions of one lonsdaleite (001) plane per four diamond (111) demonstrate the lowest energy per carbon atom, suggesting a favorable formation of single-layer lonsdaleite (001) fragments inserted in the diamond matrix. Calculated formation energies and experimental diamond (311) and lonsdaleite (331) powder X-ray diffraction patterns indicate that all biphases could be formed under high-temperature, high-pressure conditions. Following the equation of states, the bulk modulus of the diamond (111)/lonsdaleite (001) biphase is the largest one among all bulk moduli, including pristine diamond and lonsdaleite.
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4.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Bataleva Y., Palyanov Y., Borzdov Y., Bayukov O. A.
Заглавие : Processes and conditions of the origin for Fe3+-bearing magnesiowustite under lithospheric mantle pressures and temperatures
Место публикации : Minerals. - 2019. - Vol. 9, Is. 8. - Ст.474. - ISSN 2075163X (ISSN), DOI 10.3390/min9080474
Примечания : Cited References: 82. - This research was performed by state assignment of IGM SB RAS (project No. 0330-2016-0007).
Предметные рубрики: Mineral Geochemistry and Geochronology
Аннотация: An experimental study, implicated in the revealing of the conditions for the origin for Fe3+-bearing magnesiowüstite in the lithospheric mantle, was performed using Mössbauer spectroscopy of pre-synthesized samples. Experiments were carried out using a multi-anvil high-pressure split-sphere apparatus at 6.3–7.5 GPa, in the range of 1100–1650 °C in carbonate-metal, carbonate–oxide-metal, carbonate-oxide, carbide-oxide and carbonate–metal-sulphur systems. In three experimental series, oxygen fugacity gradient in the samples was created, which enabled the study of the processes of magnesiowüstite formation under oxidizing and reducing conditions (ΔlogfO2 (FMQ) values from −1 to −5). It was established that Fe3+-bearing magnesiowüstite can form both in assemblage with oxidized phases, such as carbonate or with reduced ones—metal, carbides, sulphides, graphite and diamond. According to the Mössbauer spectroscopy, the composition of synthesized magnesiowüstite varied within a range of Fe3+/ΣFe values from 0 to 0.3, with IV and VI coordination of Fe3+ depending on P, T, fO2, x-parameters. It was established that Fe3+-bearing magnesiowüstite formation processes under upper mantle P,T-conditions include redox reactions, with magnesiowüstite being (1) reductant or (2) product of interaction, (3) crystallization processes of magnesiowüstite from an oxidized melt, where magnesiowüstite acts as a sink for ferric iron and (4) iron disproportionation.
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5.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Bataleva, Yu. V., Palyanov, Yu. N., Borzdov, Yu. M., Novoselov I. D., Bayukov O. A., Sobolev N. V.
Заглавие : Conditions of formation of iron-carbon melt inclusions in garnet and orthopyroxene under P-T conditions of lithospheric mantle
Коллективы : Russian Foundation for Basic Research [16-35-60024]; [0330-2016-0007]
Место публикации : Petrology. - 2018. - Vol. 26, Is. 6. - P.565-574. - ISSN 0869-5911, DOI 10.1134/S0869591118060024. - ISSN 1556-2085(eISSN)
Примечания : Cited References: 45. - This work was supported by the Russian Foundation for Basic Research (project no. 16-35-60024) and a State Assignment (project no. 0330-2016-0007).
Предметные рубрики: EARTHS LOWER MANTLE
DIAMOND FORMATION
DEEP MANTLE
PHYSICOCHEMICAL PARAMETERS
Ключевые слова (''Своб.индексиров.''): high-pressure experiment--metal-carbon melt--graphite--diamond--co2-fluid--mantle silicates--mantle metasomatism
Аннотация: Of great importance in the problem of redox evolution of mantle rocks is the reconstruction of scenarios of alteration of Fe0- or Fe3C-bearing rocks by oxidizing mantle metasomatic agents and the evaluation of stability of these phases under the influence of fluids and melts of different compositions. Original results of high-temperature high-pressure experiments (P = 6.3 GPa, T = 1300–1500°С) in the carbide–oxide–carbonate systems (Fe3C–SiO2–(Mg,Ca)CO3 and Fe3C–SiO2–Al2O3–(Mg,Ca)CO3) are reported. Conditions of formation of mantle silicates with metallic or metal–carbon melt inclusions are determined and their stability in the presence of CO2-fluid representing the potential mantle oxidizing metasomatic agent are estimated. It is established that garnet or orthopyroxene and CO2-fluid are formed in the carbide–oxide–carbonate system through decarbonation, with subsequent redox interaction between CO2 and iron carbide. This results in the formation of assemblage of Fe-rich silicates and graphite. Garnet and orthopyroxene contain inclusions of a Fe–C melt, as well as graphite, fayalite, and ferrosilite. It is experimentally demonstrated that the presence of CO2-fluid in interstices does not affect on the preservation of metallic inclusions, as well as graphite inclusions in silicates. Selective capture of Fe–C melt inclusions by mantle silicates is one of the potential scenarios for the conservation of metallic iron in mantle domains altered by mantle oxidizing metasomatic agents.
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6.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Bataleva Y., Palyanov Y., Borzdov Y., Novoselov I., Bayukov O. A.
Заглавие : Graphite and diamond formation in the carbide–oxide–carbonate interactions (Experimental modeling under mantle P,T-conditions)
Место публикации : Minerals. - 2018. - Vol. 8, Is. 11. - Ст.522. - ISSN 2075163X (ISSN), DOI 10.3390/min8110522
Примечания : Cited References: 67. - The authors express their sincere thanks to the in-house Editor, the guest Academic Editor, and three anonymous Reviewers for helpful and constructive reviews. The authors thank S. Ovchinnikov for his assistance in implementation of Mössbauer spectroscopy measurements and A. Moskalev for his assistance in the work preparation.
Ключевые слова (''Своб.индексиров.''): cohenite--graphite--diamond--co2 fluid--carbonate--garnet--experiment--high pressure--lithospheric mantle--metasomatism
Аннотация: Experimental modeling of the formation of graphite and diamond as a result of carbide–fluid interactions was performed in the Fe3C–SiO2–Al2O3–(Mg,Ca)CO3 systems at 6.3 and 7.5 GPa and 1100–1650 °C. In the experiments with ƒO2-gradient (7.5 GPa, 1250–1350 °C), graphite + magnesiowüstite + garnet ± cohenite assemblage was formed. Graphite was produced through the redox interactions of carbide with carbonate or CO2 (reducing conditions), and redox reactions of magnesiowüstite and CO2 (oxidizing conditions). At 1450–1650 °C, crystallization of graphite, garnet, magnesiowüstite and ferrospinel, as well as generation of Fe2+,3+-rich carbonate–silicate melt occurred. This melt, saturated with carbon, acted as a medium of graphite crystallization and diamond growth on seeds. In the experiments without ƒO2-gradient (6.3 GPa), decarbonation reactions with the formation of CO2-fluid and Fe,Mg,Ca-silicates, as well as C0-producing redox reactions of CO2-fluid with cohenite were simultaneously realized. As a result, graphite (± diamond growth) was formed in assemblage with Fe2+,Fe3+,Mg-silicates and magnetite (1100–1200 °C), or with Fe3+-rich garnet and orthopyroxene (1300–1500 °C). It has been established that a potential mechanism for the crystallization of graphite or diamond growth is the oxidation of cohenite by CO2-fluid to FeO and Fe3O4, accompanied by the extraction of carbon from Fe3C and the corresponding reduction of CO2 to C0.
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7.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Bataleva Yu. V., Palyanov Y. N., Borzdov Y. M., Bayukov O. A., Zdrokov E. V.
Заглавие : Iron carbide as a source of carbon for graphite and diamond formation under lithospheric mantle P-T parameters
Место публикации : Lithos: Elsevier, 2017. - Vol. 286-287. - P.151-161. - ISSN 00244937 (ISSN), DOI 10.1016/j.lithos.2017.06.010
Примечания : Cited References: 57. - This work was supported by the Russian Foundation for Basic Research (project No. 16-35-60024) and by a State Assignment (project no. 0330-2016-0007). The authors thank the editor Marco Scambelluri, the reviewer Fabrizio Nestola and an anonymous reviewer for their helpful and constructive reviews. The authors thank A. Moskalev and M. Jolivet for their assistance in the work preparation, A. Sokol and A. Khokhryakov for useful suggestions throughout the study, S. Ovchinnikov for his assistance in implementation of the Mössbauer spectroscopy measurements.
Ключевые слова (''Своб.индексиров.''): iron carbide--graphite--diamond--sulfur-rich fluid--mantle sulfides--high-pressure experiment
Аннотация: Experimental modeling of natural carbide-involving reactions, implicated in the graphite and diamond formation and estimation of the iron carbide stability in the presence of S-bearing fluids, sulfide melts as well as mantle silicates and oxides, was performed using a multi-anvil high-pressure split-sphere apparatus. Experiments were carried out in the carbide-sulfur (Fe3C-S), carbide-sulfur-oxide (Fe3C-S-SiO2-MgO) and carbide-sulfide (Fe3C-FeS2) systems, at pressure of 6.3 GPa, temperatures in the range of 900–1600 °C and run time of 18–40 h. During the interaction of cohenite with S-rich reduced fluid or pyrite at 900–1100 °C, extraction of carbon from carbide was realized, resulting in the formation of graphite in assemblage with pyrrhotite and cohenite. At higher temperatures complete reaction of cohenite with newly-formed sulfide melt was found to produce metal-sulfide melt with dissolved carbon (Fe64S27C9 (1200 °C)–Fe54S40C6 (1500 °C), at.%), which acted as a crystallization medium for graphite (1200–1600 °C) and diamond growth on seeds (1300–1600 °C). Reactions of cohenite and oxides with S-rich reduced fluid resulted in the formation of graphite in assemblage with highly ferrous orthopyroxene and pyrrhotite (900–1100 °C) or in hypersthene formation, as well as graphite crystallization and diamond growth on seeds in the Fe-S-C melt (1200–1600 °C). We show that the main processes of carbide interaction with S-rich fluid or sulfide melt are recrystallization of cohenite (900–1100 °C), extraction of carbon and iron in the sulfide melt, and graphite formation and diamond growth in the metal-sulfide melt with dissolved carbon. Our results evidence that iron carbide can act as carbon source in the processes of natural graphite and diamond formation under reduced mantle conditions. We experimentally demonstrate that cohenite in natural environments can be partially consumed in the reactions with mantle silicates and oxides, and is absolutely unstable in the presence of S-bearing reduced fluid or sulfide melt at temperatures higher than 1100 °C, under lithospheric mantle pressures.
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8.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Ivanenko A. A., Tambasov I. A., Pshenichnaia A. A., Shestakov N. P.
Заглавие : Flexible film broadband absorber based on diamond-graphite mixture and polyethylene
Место публикации : Opt. Mater.: Elsevier Science, 2017. - Vol. 73. - P.388-392. - ISSN 09253467 (ISSN), DOI 10.1016/j.optmat.2017.08.041
Примечания : Cited References: 54. - This study was supported by the Russian Foundation for Basic Research (Grants No. 16-32-00302 мол_а), by the Council for Grants of the President of the Russian Federation (SP-317.2015.1), by Russian Foundation for Basic Research, Government of Krasnoyarsk Territory, Krasnoyarsk Region Science and Technology Support Fund to the research project No. 16-42-243059 р_мол_а and No. 16-48-242092 р_офи_м.
Ключевые слова (''Своб.индексиров.''): flexible film broadband absorption--diamond-graphite mixture--polyethylene--reflectivity--transmittance
Аннотация: Flexible film broadband absorber based on diamond-graphite mixture and polyethylene was fabricated by hot pressing. The film thickness of the absorber was 90 μm. We have measured angular reflectivity, diffusional reflectivity and transmittance in the range 85–8000 cm−1 (117–1.25 μm) in order to determine the absorption. It was shown that room temperature pressing of mesh print with 250 μm step significantly reduces reflectivity of the absorber. The absorption was over 0.85 in the range 85–320 cm−1 (117–31.25 μm) and 0.98 in the range 320–8000 cm−1 (31.25–1.25 μm). We believe that the designed and manufactured absorber might become a promising material for optical devices where high broadband absorption and flexibility are required.
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9.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Bataleva Yu. V., Palyanov Y .N., Sokol A. G., Borzdov Y. M., Bayukov O. A.
Заглавие : Wüstite stability in the presence of a CO2-fluid and a carbonate-silicate melt: Implications for the graphite/diamond formation and generation of Fe-rich mantle metasomatic agents
Место публикации : Lithos: Elsevier, 2016. - Vol. 244. - P.20-29. - ISSN 00244937 (ISSN), DOI 10.1016/j.lithos.2015.12.001
Примечания : Cited References: 68. - This work was supported by the Russian Science Foundation under grant no. 14-27-00054. The authors thank A. Moskalev for his assistance in the work preparation, A. Khokhryakov for useful suggestions throughout the study, and S. Ovchinnikov for his assistance in implementation of Mössbauer spectroscopy measurements. The authors thank editor M. Scambelluri, and two anonymous reviewers for their useful comments, which helped to profoundly improve the manuscript.
Предметные рубрики: EARTHS LOWER MANTLE
FERRIC IRON CONTENT
DIAMOND FORMATION
MINERAL INCLUSIONS
NATURAL DIAMOND
OXIDATION-STATE
DEEP MANTLECRUST
LITHOSPHERIC MANTLE
OXYGEN FUGACITY
OCEANIC-CRUST
Ключевые слова (''Своб.индексиров.''): wustite--co2-fluid--carbonate-silicate melt--decarbonation--graphite formation--hpht experiment
Аннотация: Experimental simulation of the interaction of wüstite with a CO2-rich fluid and a carbonate-silicate melt was performed using a multianvil high-pressure split-sphere apparatus in the FeO-MgO-CaO-SiO2-Al2O3-CO2 system at a pressure of 6.3GPa and temperatures in the range of 1150°C-1650°C and with run time of 20h. At relatively low temperatures, decarbonation reactions occur in the system to form iron-rich garnet (Alm75Prp17Grs8), magnesiowüstite (Mg#≤0.13), and CO2-rich fluid. Under these conditions, magnesiowüstite was found to be capable of partial reducing CO2 to C0 that leads to the formation of Fe3+-bearing magnesiowüstite, crystallization of magnetite and metastable graphite, and initial growth of diamond seeds. At T≥1450°C, an iron-rich carbonate-silicate melt (FeO~56wt.%, SiO2~12wt.%) forms in the system. Interaction between (Fe,Mg)O, SiO2, fluid and melt leads to oxidation of magnesiowüstite and crystallization of fayalite-magnetite spinel solid solution (1450°C) as well as to complete dissolution of magnesiowüstite in the carbonate-silicate melt (1550°C-1650°C). In the presence of both carbonate-silicate melt and CO2-rich fluid, dissolution (oxidation) of diamond and metastable graphite was found to occur. The study results demonstrate that under pressures of the lithospheric mantle in the presence of a CO2-rich fluid, wüstite/magnesiowüstite is stable only at relatively low temperatures when it is in the absolute excess relative to CO2-rich fluid. In this case, the redox reactions, which produce metastable graphite and diamond with concomitant partial oxidation of wüstite to magnetite, occur. Wüstite is unstable under high concentrations of a CO2-rich fluid as well as in the presence of a carbonate-silicate melt: it is either completely oxidized or dissolves in the melt or fluid phase, leading to the formation of Fe2+- and Fe3+-enriched carbonate-silicate melts, which are potential metasomatic agents in the lithospheric mantle. © 2015 Elsevier B.V.
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10.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Bataleva, Yu. V., Palyanov, Yu. N., Borzdov, Yu. M., Bayukov O. A., Sobolev N. V.
Заглавие : Conditions for diamond and graphite formation from iron carbide at the P-T parameters of lithospheric mantle
Коллективы : Russian Science Foundation [14-27-00054]
Место публикации : Russ. Geol. Geophys.: Elsevier Science, 2016. - Vol. 57, Is. 1: Tectonics, geodynamics, and petrology of earth’s lithosphere and mantle (to the 80th birthday of Academician Nikolai Leontievich Dobretsov). - P.176-189. - ISSN 1068-7971, DOI 10.1016/j.rgg.2016.01.012. - ISSN 1878-030X(eISSN)
Примечания : Cited References:55. - This work was supported by the Russian Science Foundation under Grant No. 14-27-00054.
Предметные рубрики: DEEP CARBON-CYCLE
EARTHS MANTLE
MINERAL INCLUSIONS
HIGH-PRESSURE
KOKCHETAV MASSI
SUBDUCTION ZONES
REDOX BUDGET
FERRIC IRON
MOSSBAUER
METAL
Ключевые слова (''Своб.индексиров.''): iron carbide--wusite--graphite--diamond--oxides--olivine--subduction--redox interaction--lithospheric mantle--high-pressure experiment
Аннотация: To estimate conditions for the stability of iron carbide under oxidation conditions and to assess the possibility of formation of elemental carbon by interaction between iron carbide and oxides, experimental modeling of redox interaction in the systems Fe3C-Fe2O3 and Fe3C-Fe2O3-MgO-SiO2 was carried out on a split-sphere high-pressure multianvil apparatus at 6.3 GPa and 900-1600 degrees C for 18-20 h. During carbide-oxide interaction in the system Fe3C-Fe2O3, graphite crystallizes in assemblage with Fe3+-containing wusite. Graphite forms from carbide carbon mainly by cohenite oxidation: Fe3C + 3Fe(2)O(3) - 9FeO + C-0 and FeO + Fe3C - (Fe2+, Fe3+)O + C-0. At above-solidus temperatures (= 1400 degrees C), when metal-carbon melt is oxidized by wusite, graphite and diamond crystallize by the redox mechanism and form the Fe3+-containing wstite + graphite/diamond assemblage. Interaction in the system Fe3C-Fe2O3-MgO-SiO2 results in the formation of Fe3+-containing mannesiowusite-olivine-graphite assemblage. At = 1500 degrees C, two melts with contrasting f(O2) values are generated: metal-carbon and silicate-oxide; their redox interaction leads to graphite crystallization and diamond growth. Under oxidation conditions, iron carbide is unstable in the presence of iron, silicon, and magnesium oxides, even at low temperatures. Iron carbide-oxide interaction at the mantle temperatures and pressures leads to the formation of elemental carbon; graphite is produced from carbide carbon mainly by redox reactions of cohenite (or metal-carbon melt) with Fe2O3 and FeO as well as by interaction between metal-carbon and silicate-oxide melts. The results obtained suggest that cohenite can be a potential source of carbon during graphite (diamond) formation in the lithospheric mantle and the interaction of iron carbide with iron, silicon, and magnesium oxides, during which carbon is extracted can be regarded as a process of the global carbon cycle. (C) 2016, V.S. Sobolev IGM, Siberian Branch of the RAS. Published by Elsevier B.V. All rights reserved.
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