Elena Bykova

Elena Bykova
Carnegie Institution for Science · Department of Geophysical Laboratory

Dr. rer. nat.

About

247
Publications
51,287
Reads
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2,972
Citations
Citations since 2016
189 Research Items
2702 Citations
20162017201820192020202120220100200300400500
20162017201820192020202120220100200300400500
20162017201820192020202120220100200300400500
20162017201820192020202120220100200300400500
Additional affiliations
March 2011 - present
University of Bayreuth
Position
  • PhD Student
March 2011 - March 2015
University of Bayreuth
Position
  • PhD Student
February 2006 - February 2011
Russian Academy of Sciences
Position
  • Master's Student
Education
September 2005 - May 2010
Novosibirsk State University
Field of study
  • chemistry

Publications

Publications (247)
Article
Full-text available
Chemical stability of the alkali halides NaCl and KCl has allowed for their use as inert media in high-pressure high-temperature experiments. Here we demonstrate the unexpected reactivity of the halides with metals (Y, Dy, and Re) and iron oxide (FeO) in a laser-heated diamond anvil cell, thus providing a synthetic route for halogen-containing bina...
Article
Full-text available
Transition metal borides are known due to their attractive mechanical, electronic, refractive, and other properties. A new class of rhenium borides was identified by synchrotron single-crystal X-ray diffraction experiments in laser-heated diamond anvil cells between 26 and 75 GPa. Recoverable to ambient conditions, compounds rhenium triboride (ReB3...
Article
Tungsten tetraboride has been known so far as a non-stoichiometric compound with a variable composition (e.g. WB4−x, WB4+x). Its mechanical properties could exceed those of hard tungsten carbide, which is widely used nowadays in science and technology. The existence of stoichiometric WB4 has not been proven yet, and its structure and crystal chemis...
Article
Full-text available
Polynitrogen molecules are attractive for high-energy-density materials due to energy stored in nitrogen–nitrogen bonds; however, it remains challenging to find energy-efficient synthetic routes and stabilization mechanisms for these compounds. Direct synthesis from molecular dinitrogen requires overcoming large activation barriers and the reaction...
Article
The high-pressure structural and vibrational properties of a layered transition metal dichalcogenide 2H−NbSe2 were investigated using single-crystal x-ray diffraction and Raman spectroscopy, demonstrating its structural stability up to 35 GPa. The lattice compressibility changes character from being highly anisotropic at low pressures to largely is...
Article
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The pressure-induced Mott insulator-to-metal transitions are often accompanied by a collapse of magnetic interactions associated with delocalization of 3d electrons and high-spin to low-spin (HS-LS) state transition. Here, we address a long-standing controversy regarding the high-pressure behavior of an archetypal Mott insulator FeBO3 and show the...
Article
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The metal-insulator transition driven by electronic correlations is one of the most fundamental concepts in condensed matter. In mixed-valence compounds, this transition is often accompanied by charge ordering (CO), resulting in the emergence of complex phases and unusual behaviors. The famous example is the archetypal mixed-valence mineral magneti...
Article
Magnetic order is frustrated on the orthorhombic lattice of van der Waals layered FeOCl. Antiferromagnetic (AFM) order is attained at ambient pressure upon cooling through TN=81 K, due to an accompanying monoclinic lattice distortion lifting the magnetic frustration. Within the paramagnetic state at 293 K, an incommensurate structural modulation ap...
Article
Understanding of recently reported putative close-to-room-temperature superconductivity in C–S–H compounds at 267 GPa demands a reproducible synthesis protocol as well as knowledge of the compounds' structure and composition. We synthesized C–S–H compounds with various carbon compositions at high pressures from elemental carbon C and methane CH4, s...
Article
Single-crystal synchrotron x-ray diffraction, Raman spectroscopy, and first principles calculations have been used to identify the structure of the high-pressure (HP) phase of molecular methane above 20 GPa up to 71 GPa at room temperature. The structure of the HP phase is trigonal R3, which can be represented as a distortion of the cubic phase B,...
Preprint
Full-text available
Single-crystal synchrotron X-ray diffraction, Raman spectroscopy, and first principles calculations have been used to identify the structure of the high-pressure (HP) phase of molecular methane above 20 GPa up to 71 GPa. The structure of HP phase is trigonal R3, which can be represented as a distortion of the cubic phase B, previously documented at...
Preprint
Full-text available
Understanding of recently reported putative close-to-room-temperature superconductivity in C-S-H compounds at 267 GPa demands reproducible synthesis protocol as well as knowledge of its structure and composition. We synthesized C-S-H compounds with various carbon composition at high pressures from elemental C and methane CH4, sulfur S, and molecula...
Article
Full-text available
As the most abundant material of rocky planets, high-pressure polymorphs of iron- and aluminum-bearing magnesium silicates have long been sought by both observations and experiments. Meanwhile, it was recently revealed that iron oxides form (FeO)m(Fe2O3)n homologous series above ∼10 GPa according to laboratory high-pressure experiments. Here, we re...
Article
Most of the studied two-dimensional (2D) materials are based on highly symmetric hexagonal structural motifs. In contrast, lower-symmetry structures may have exciting anisotropic properties leading to various applications in nanoelectronics. In this work we report the synthesis of nickel diazenide NiN2 which possesses atomic-thick layers comprised...
Article
Three single crystals of CaTi2O4 (CT)-type, CaFe2O4 (CF)-type, and new low-density CaFe2O4 (LD-CF) related MgAl2O4 were synthesized at 27 GPa and 2500 °C and also CT-type MgAl2O4 at 45 GPa and 1727 °C using conventional and advanced multi-anvil technologies, respectively. The structures of CT-type and LD-CF related MgAl2O4 were analyzed by single-c...
Article
The Front Cover shows a possible deep oxygen cycle in early Earth. FeOOH (“rust”), produced by anoxygenic photosynthesis and accumulated on the ocean floor, was transferred to the lower mantle by subducting slabs. At high pressures and temperatures, FeOOH decomposes into a mixture of complex iron oxides, water, and oxygen. Oxidizing fluids rising t...
Article
Goethite, α‐FeOOH, is a major phase among oxidized iron species, commonly called rust. We studied the behavior of iron (III) oxyhydroxide up to 81 GPa and 2100 K using in situ synchrotron single‐crystal X‐ray diffraction. At high pressure‐temperature conditions FeOOH decomposes forming oxygen‐rich fluid and different mixed valence iron oxides (prev...
Article
Nitrogen and water are very abundant in nature; however, the way they chemically react at extreme pressure–temperature conditions is unknown. Below 6 GPa, they have been reported to form clathrate compounds. Here, we present Raman spectroscopy and x-ray diffraction studies in the H2O–N2 system at high pressures up to 140 GPa. We find that clathrate...
Article
Full-text available
The high-precision X-ray diffraction setup for work with diamond anvil cells (DACs) in interaction chamber 2 (IC2) of the High Energy Density instrument of the European X-ray Free-Electron Laser is described. This includes beamline optics, sample positioning and detector systems located in the multipurpose vacuum chamber. Concepts for pump–probe X-...
Article
Synthesis and characterization of nitrogen-rich materials is important for the design of novel high energy density materials due to extremely energetic low-order nitrogen–nitrogen bonds. The balance between the energy output and stability may be achieved if polynitrogen units are stabilized by resonance as in cyclo-N5− pentazolate salts. Here we de...
Article
We synthesized two C-S-H compounds from a mixture of carbon and sulfur in hydrogen—C:(H2S)2H2 and from sulfur in mixed methane-hydrogen fluids—(CH4)x(H2S)(2−x)H2 at 4 GPa. X-ray synchrotron single-crystal diffraction and Raman spectroscopy have been applied to these samples up to 58 and 143 GPa, respectively. Both samples show a similar Al2Cu-type...
Article
The ultrafast synthesis of ε-Fe3N1+x in a diamond-anvil cell (DAC) from Fe and N2 under pressure was observed using serial exposures of an X-ray free electron laser (XFEL). When the sample at 5 GPa was irradiated by a pulse train separated by 443 ns, the estimated sample temperature at the delay time was above 1400 K, confirmed by in situ transform...
Article
Extreme pressures and temperatures are known to drastically affect the chemistry of iron oxides, resulting in numerous compounds forming homologous series nFeOmFe2O3 and the appearance of FeO2. Here, based on the results of in situ single-crystal x-ray diffraction, Mössbauer spectroscopy, x-ray absorption spectroscopy, and density-functional theory...
Article
Full-text available
Alkaline earth metal peroxides are typical examples of ionic compounds containing polyanions. We herein report a stable BaO2 phase at high pressure up to 130 GPa found via a first-principles computational structure search and high-pressure experimental investigations. The identified monoclinic structure (space group C2/m) can be derived by sublatti...
Article
The synthesis of polynitrogen compounds is of great importance due to their potential as high energy density materials (HEDM), but because of the intrinsic instability of these compounds, their synthesis and stabilization is a fundamental challenge. Polymeric nitrogen units which may be stabilized in compounds with metals at high pressure are now r...
Article
Direct reaction between nitrogen and tantalum at approximately 100 GPa results in the energetic nitrogen‐rich compounds TaN4 and TaN5, which feature N4 chains and unprecedented branched single‐bonded polymeric nitrogen chains in the crystal structures, respectively. TaN5 possesses an extraordinary volumetric energy density of 18 kJ cm⁻³, exceeding...
Preprint
Full-text available
The structure and properties of metal-hydrides at extreme conditions is key to the understanding of hydrogen-storage technologies, high-temperature superconductivity, and the dynamics of planetary cores. Here we investigate the phase relations and magnetic properties of iron hydrides, including two novel FeH x compounds, up to 63 GPa and 1800 K by...
Preprint
Full-text available
We synthesized two C-S-H compounds from a mixture of carbon and sulfur in hydrogen and from sulfur in mixed methane-hydrogen fluids at 4 GPa. X-ray synchrotron single-crystal diffraction and Raman spectroscopy have been applied to these samples up to 58 and 143 GPa, respectively. Both samples show a similar Al2Cu type I4/mcm basic symmetry, while t...
Article
Full-text available
A structure and equation of the state of δ-AlOOH has been studied at room temperature, up to 29.35 GPa, by means of single crystal X-ray diffraction in a diamond anvil cell using synchrotron radiation. Above ~10 GPa, we observed a phase transition with symmetry changes from P21nm to Pnnm. Pressure-volume data were fitted with the second order Birch...
Article
Full-text available
The high-pressure phase transition of strontianite (SrCO3) was investigated at ambient temperature by means of powder and single-crystal X-ray diffraction. The samples were compressed in a diamond anvil cell to a maximum pressure of 49 GPa. Structure refinements confirm the existence of SrCO3 in the low pressure aragonite-type phase Pmcn (62) up to...
Preprint
Polynitrogen molecules represent the ultimate high energy-density materials as they have a huge potential chemical energy originating from their high enthalpy. However, synthesis and storage of such compounds remain a big challenge because of difficulties to find energy efficient synthetic routes and stabilization mechanisms. Compounds of metals wi...
Article
X-ray synchrotron diffraction (XRD) measurements of single-crystal and powder molybdenum disulfide MoS2 are performed at pressures (P) up to 78 GPa and temperatures (T) of 20 to 298 K in diamond-anvil cells. The results on single crystals demonstrate a sharp pressure induced isosymmetric phase transition of 2Hc to 2Ha modification at 23 GPa at 40 a...
Article
Full-text available
It is widely accepted that the lower mantle consists of mainly three major minerals-ferropericlase, bridgmanite and calcium silicate perovskite. Ferropericlase ((Mg,Fe)O) is the second most abundant of the three, comprising approximately 16-20 wt% of the lower mantle. The stability of ferropericlase at conditions of the lowermost mantle has been hi...
Article
Full-text available
The crystal structure of MgCO 3 -II has long been discussed in the literature where DFT-based model calculations predict a pressure-induced transition of the carbon atom from the sp² to the sp³ type of bonding. We have now determined the crystal structure of iron-bearing MgCO 3 -II based on single-crystal X-ray diffraction measurements using synchr...
Article
Laser heating of rhenium in a diamond anvil cell to 3000±300 K at about 200 GPa results in formation of two previously unknown rhenium carbides, hexagonal WC‐type structured ReC and orthorhombic TiSi2‐type structured ReC2. The shortest C–C distances [1.758(3) Å at 219(5) GPa and 1.850(4) Å at 180(7) GPa] found in honeycomb‐like carbon nets in the s...
Article
Full-text available
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Article
Metal–inorganic frameworks Hf4N20⋅N2, WN8⋅N2 and Os5N28⋅N2 built of transition metals and polymeric nitrogen linkers were synthesized by M. Bykov et al. in a one‐step synthesis from elements at high‐pressure conditions (DOI: 10.1002/anie.202002487). The channel‐type pores are filled with ordered one‐dimensional arrays of nitrogen molecules. Due to...
Article
Metall‐anorganische Gerüstverbindungen Hf4N20⋅N2, WN8⋅N2 und Os5N28⋅N2, die aus Übergangsmetallen und polymeren Stickstofflinkern aufgebaut sind, wurden von M. Bykov et al. in einer einstufigen Synthese aus den Elementen unter Hochdruckbedingungen hergestellt (DOI: 10.1002/ange.202002487). Die kanalartigen Poren sind mit eindimensionalen Anordnunge...
Article
Full-text available
The synthesis of various polynitrogen compounds have been actively pursued for the past hundred years due to their potential as high energy density materials. Polynitrides are intrinsically thermodynamically unstable at ambient conditions and require peculiar synthetic approaches. Here we report one-step synthesis of metal-inorganic frameworks Hf4N...
Article
Full-text available
A one‐step high‐pressure synthetic route is used to complex metal–inorganicframeworks built of transition metals(Hf, Os, and W) that are connected via polymeric nitrogen linkers. The pores are filled with ordered one‐dimensional arrays of nitrogen molecules. Owing to the conjugated π‐systems, these inorganic polymers are conductive materials. Abst...
Article
Full-text available
Ein gemischtvalentes Eisenoxid mit ungewöhnlicher Fe5O6‐Stöchiometrie wurde synthetisiert, wie S. V. Ovsyannikov et al. in ihrer Zuschrift (DOI: 10.1002/ange.201914988) beschreiben. Nahe 275 K durchläuft das Material einen Ladungsordnungsübergang des Verwey‐Typs, der einhergeht mit einer Dimerisierung in den Eisenketten und der Bildung neuer Fe‐Fe‐...
Article
Full-text available
A novel mixed‐valent iron oxide with an unconventional Fe5O6 stoichiometry was synthesized by S. V. Ovsyannikov et al., as reported in their Communication (DOI: 10.1002/anie.201914988). Near 275 K, the material undergoes a Verwey‐type charge‐ordering transition that is concurrent with a dimerization in the iron chains and the formation of new Fe−Fe...
Preprint
Full-text available
Laser heating of rhenium in a diamond anvil cell to 3000 K at about 200 GPa results in formation of two previously unknown rhenium carbides, hexagonal WC-type structured ReC and orthorhombic TiSi2-type structured ReC2. The Re-C slid solution formed at multimegabar pressure has the carbon content of ca. 20 at%. Unexpectedly long C-C distances (ca. 1...
Article
Full-text available
Iron(III) oxide-hydroxide, FeOOH, is abundant in the banded iron formations (BIFs). Recent studies indicate that BIFs may carry water down to the lower mantle with subducting slabs. The previous experiments investigating the properties of FeOOH at extreme pressures (P) and temperatures (T) were performed in diamond anvil cells (DACs), where it was...
Article
Full-text available
Functional oxides whose physicochemical properties may be reversibly changed at normal conditions are perspective candidates for the use in next‐generation nanoelectronic devices. To date, vanadium dioxide (VO2) is the only known simple transition metal oxide that demonstrates a near‐room‐temperature metal–insulator transition that may be used in s...
Article
Full-text available
Functional oxides whose physicochemical properties may be reversibly changed at normal conditions are perspective candidates for the use in next‐generation nanoelectronic devices. To date, vanadium dioxide (VO2) is the only known simple transition metal oxide that demonstrates a near‐room‐temperature metal–insulator transition that may be used in s...
Article
Full-text available
A structure and equation of the state of δ-AlOOH has been studied at room temperature, up to 29.35 GPa, by means of single crystal X-ray diffraction in a diamond anvil cell using synchrotron radiation. Above ~10 GPa, we observed a phase transition with symmetry changes from P21nm to Pnnm. Pressure-volume data were fitted with the second order Birch...
Article
Full-text available
Owing to its outstanding elastic properties, the nitride spinel γ‐Si3 N4 is of considered interest for materials scientists and chemists. DFT calculations suggest that Si 3 N 4 ‐analog beryllium phosphorus nitride BeP2 N4 adopts the spinel structure at elevated pressures as well and shows outstanding elastic properties. Herein, we investigate phena...
Article
Owing to its outstanding elastic properties, the nitride spinel γ‐Si3 N4 is of considered interest for materials scientists and chemists. DFT calculations suggest that Si 3 N 4 ‐analog beryllium phosphorus nitride BeP2 N4 adopts the spinel structure at elevated pressures as well and shows outstanding elastic properties. Herein, we investigate phena...
Article
Full-text available
The synthesis of polynitrogen compounds is of fundamental importance due to their potential as environmentally-friendly high energy density materials. Attesting to the intrinsic difficulties related to their formation, only three polynitrogen ions, bulk stabilized as salts, are known. Here, magnesium and molecular nitrogen are compressed to about 5...