A5035807240- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- High-pressure geophysics and materials
- Geological and Geochemical Analysis
- Diamond and Carbon-based Materials Research
- Inorganic Chemistry and Materials
- Catalysts for Methane Reforming
- Catalysis and Hydrodesulfurization Studies
- Catalytic Processes in Materials Science
- MXene and MAX Phase Materials
- Crystal Structures and Properties
- Rare-earth and actinide compounds
- Boron and Carbon Nanomaterials Research
- Geochemistry and Geologic Mapping
- Advanced materials and composites
- Metal and Thin Film Mechanics
- Inorganic Fluorides and Related Compounds
- Hydrogen Storage and Materials
- Organometallic Complex Synthesis and Catalysis
- Geochemistry and Elemental Analysis
- earthquake and tectonic studies
- Pigment Synthesis and Properties
- Microstructure and Mechanical Properties of Steels
- NMR spectroscopy and applications
- Astro and Planetary Science
University of Oxford
2023-2024
Diamond Light Source
2024
Boreskov Institute of Catalysis
2023
University of Bayreuth
2017-2021
Institut Charles Gerhardt Montpellier
2021
Centre National de la Recherche Scientifique
2021
Université de Montpellier
2021
Bayer (Germany)
2019-2020
European Synchrotron Radiation Facility
2019
Bayerisches Landesamt für Umwelt
2019
Poly-nitrogen compounds have been considered as potential high energy density materials for a long time due to the large number of energetic N-N or N=N bonds. In most cases nitrogen content and stability at ambient conditions are mutually exclusive, thereby making synthesis such challenging. One way stabilize is application pressure. Here, through direct reaction between Fe N
Abstract The synthesis of polynitrogen compounds is fundamental importance due to their potential as environmentally-friendly high energy density materials. Attesting the intrinsic difficulties related formation, only three ions, bulk stabilized salts, are known. Here, magnesium and molecular nitrogen compressed about 50 GPa laser-heated, producing two chemically simple salts anions, MgN 4 Mg 2 N . Single-crystal X-ray diffraction reveals infinite anionic polythiazyl-like 1D N-N chains in...
Abstract A nitrogen‐rich compound, ReN 8 ⋅x N 2 , was synthesized by a direct reaction between rhenium and nitrogen at high pressure temperature in laser‐heated diamond anvil cell. Single‐crystal X‐ray diffraction revealed that the crystal structure, which is based on framework, has rectangular‐shaped channels accommodate molecules. Thus, despite very synthesis pressure, exceeding 100 GPa, an inclusion compound. The amount of trapped (x) depends conditions. polydiazenediyl chains [−N=N−] ∞...
The diamond anvil cell (DAC) technique combined with laser heating is one of the major methods for studying materials at high pressure and temperature conditions. In this work, we present a transferable double-sided setup DACs in situ determination. allows precise samples inside DAC pressures above 200 GPa could be synchrotron beamline equipment. It can applied to X-ray diffraction transmission microscopy experiments. setup, use high-magnification low working distance infinity corrected...
An experimental platform for dynamic diamond anvil cell (dDAC) research has been developed at the High Energy Density (HED) Instrument European X-ray Free Electron Laser (European XFEL). Advantage was taken of high repetition rate XFEL (up to 4.5 MHz) collect pulse-resolved MHz diffraction data from samples as they are dynamically compressed intermediate strain rates (≤10 3 s −1 ), where up 352 images can be collected a single pulse train. The set-up employs piezo-driven dDACs capable...
Abstract Feldspars are rock-forming minerals that make up most of the Earth’s crust. Along mantle geotherm, feldspars stable at pressures to 3 GPa and may persist metastably higher under cold conditions. Previous structural studies limited ~10 GPa, have shown dominant mechanism pressure-induced deformation is tilting AlO 4 SiO tetrahedra in a tetrahedral framework. Herein, based on results situ single-crystal X-ray diffraction 27 we report discovery new high-pressure polymorphs anorthite...
Extreme pressures and temperatures are known to drastically affect the chemistry of iron oxides resulting in numerous compounds forming homologous series $n$FeO$\cdot m$Fe$_2$O$_3$ appearance FeO$_2$. Here, based on results \emph{in situ} single-crystal X-ray diffraction, M\"ossbauer spectroscopy, absorption DFT+dynamical mean-field theory calculations we demonstrate that high pressure cubic FeO$_2$ isostructural FeO$_2$H$_{0.5}$ is ferric (Fe$^{3+}$), oxygen has a formal valence less than...
A portable double-sided pulsed laser heating system for diamond anvil cells has been developed that is able to stably produce pulses as short a few microseconds with repetition frequencies up 100 kHz. In situ temperature determination possible by collecting and fitting the thermal radiation spectrum specific wavelength range (particularly, between 650 nm 850 nm) Planck function. Surface information can also be time-resolved using gated detector synchronized pulse modulation space-resolved...
Laser heating in a diamond anvil cell (DAC) is common method for studying material behavior at high-pressure and high-temperature conditions. It has been previously proven that during continuous wave (CW) laser of sample, carbon the anvils mobilized, its diffusion into sample can lead to undesirable chemical reactions, which, if not detected, may cause misinterpretations results experiment. Minimizing time with use pulsed (PL) thought reduce risk possible contamination sample; however, this...
Abstract Goethite, α‐FeOOH, is a major phase among oxidized iron species, commonly called rust. We studied the behavior of (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 different mixed valence oxides (previously known phases Fe 2 O 3 , 4 5 7 novel 10 6.32 9 ). Rust form as byproduct anoxygenic prokaryote metabolism that took place massively from about...
Abstract The high‐pressure behavior of non‐metal nitrides is special interest for inorganic and theoretical chemistry as well materials science, these compounds feature intriguing elastic properties. double nitride α‐BP 3 N 6 was investigated by in situ single‐crystal X‐ray diffraction (XRD) upon cold compression to a maximum pressure about 42 GPa, its isothermal bulk modulus at ambient conditions determined be 146(6) GPa. At the sample laser‐heated, which resulted formation an unprecedented...
The atomic and electronic structures of ${\mathrm{Cu}}_{2}\mathrm{H}$ CuH have been investigated by high-pressure nuclear magnetic resonance spectroscopy up to 96 GPa, X-ray diffraction 160 density functional theory-based calculations. Metallic was synthesized at a pressure 40 semimetallic 90 found stable GPa. For ${\mathrm{Cu}}_{2}\mathrm{H}$, experiments computations show an anomalous increase in the state Fermi level for hydrogen $1s$ states formation network range 43--58 together with...
Abstract A nitrogen‐rich compound, ReN 8 ⋅x N 2 , was synthesized by a direct reaction between rhenium and nitrogen at high pressure temperature in laser‐heated diamond anvil cell. Single‐crystal X‐ray diffraction revealed that the crystal structure, which is based on framework, has rectangular‐shaped channels accommodate molecules. Thus, despite very synthesis pressure, exceeding 100 GPa, an inclusion compound. The amount of trapped (x) depends conditions. polydiazenediyl chains [−N=N−] ∞...
Abstract Carbonates play an important role in the transport and storage of carbon Earth’s mantle. However, abundance carbonates subduction zones is still unknown quantity. To determine most abundant accessory phases how they influence dynamical processes that operate within Earth, investigations on vibrational, elastic, thermodynamic properties these are crucial for interpreting seismological observations. Recently, nuclear inelastic scattering (NIS) method has proved to be a useful tool...
The reduction of Co-based oxides doped with Al3+ ions has been studied using in situ XRD and TPR techniques. Al3+-modified Co3O4 the Al mole fraction Al/(Co + Al) = 1/6; 1/7.5 were prepared via coprecipitation, further calcination at 500 850 °C. Using HAADF-STEM combined EDS element mapping, cations dissolved lattice; however, cation distribution differed depended on temperature. Heating °C led to formation an inhomogeneous (Co,Al)3O4 solid solution; treatment provoked partial decomposition...
Abstract This study is devoted to the detailed in situ Raman spectroscopy investigation of propane C 3 H 8 laser-heated diamond anvil cells range pressures from 22 GPa and temperatures 900 3000 K. We show that propane, while being exposed particular thermobaric conditions, could react, leading formation hydrocarbons, both saturated unsaturated as well soot. Our results suggest be a precursor heavy hydrocarbons will produce more than just sooty material when subjected extreme conditions....
The crystal structure of MgCO 3 -II has long been discussed in the literature where DFT-based model calculations predict a pressure-induced transition carbon atom from sp 2 to type bonding. We have now determined iron-bearing based on single-crystal X-ray diffraction measurements using synchrotron radiation. laser-heated synthetic (Mg 0.85 Fe 0.15 )CO single at 2500 K and 98 GPa observed formation monoclinic phase with composition 2.53 0.47 )C O 9 space group C 2/ m that contains...
Abstract The high‐pressure behavior of non‐metal nitrides is special interest for inorganic and theoretical chemistry as well materials science, these compounds feature intriguing elastic properties. double nitride α‐BP 3 N 6 was investigated by in situ single‐crystal X‐ray diffraction (XRD) upon cold compression to a maximum pressure about 42 GPa, its isothermal bulk modulus at ambient conditions determined be 146(6) GPa. At the sample laser‐heated, which resulted formation an unprecedented...
Iron(III) oxide-hydroxide, FeOOH, is abundant in the banded iron formations (BIFs). Recent studies indicate that BIFs may carry water down to lower mantle with subducting slabs. The previous experiments investigating properties of FeOOH at extreme pressures (P) and temperatures (T) were performed diamond anvil cells (DACs), where it was compressed inside alkali metal halide pressure-transmitting media (2). Alkali halides such as NaCl or KCl are expected be chemically inert; therefore, they...
At high pressures, autoionization – along with polymerization and metallization is one of the responses simple molecular systems to a rise in electron density. Nitrosonium nitrate (NO + NO 3 − ), known for this property, has attracted large interest recent decades was reported be synthesized at pressure temperature from variety nitrogen–oxygen precursors, such as N 2 O 4 , –O mixtures. However, its structure not been determined unambiguously. Here, we present first solution refinement...
The methane phase diagram is extremely important to understand the physical properties of ice giants─Uranus and Neptune. Several experimental studies using diamond anvil cells (DACs) combined with laser heating have reported formation from at pressures 10–80 GPa temperatures above 2000 K, corresponding interiors these planets. These results, however, are probably affected by presence metallic heat absorbers, widely used in all previously experiments interacting hydrogen high pressure. In...
A new diamond anvil cell experimental approach has been implemented at the European x-ray Free Electron Laser, combining pulsed laser heating with MHz diffraction. Here, we use this setup to determine liquidus temperatures under extreme conditions, based on determination of time-resolved crystallization. The focus is a Fe-Si-O ternary system, relevant for planetary cores. This diagnostic complemented by finite-element model, reproducing temporal temperature profiles measured experimentally...