A5006827262- High-pressure geophysics and materials
- Geological and Geochemical Analysis
- earthquake and tectonic studies
- Geomagnetism and Paleomagnetism Studies
- Hydrocarbon exploration and reservoir analysis
- Diamond and Carbon-based Materials Research
- Metallurgical Processes and Thermodynamics
- Advanced X-ray Imaging Techniques
- Thermodynamic and Structural Properties of Metals and Alloys
- Nuclear Physics and Applications
- X-ray Spectroscopy and Fluorescence Analysis
- Material Properties and Failure Mechanisms
- Thermal and Kinetic Analysis
- Microstructure and Mechanical Properties of Steels
- Advanced X-ray and CT Imaging
- Geological and Geophysical Studies
- Medical Imaging Techniques and Applications
- Methane Hydrates and Related Phenomena
- Metallurgy and Cultural Artifacts
- Chemical Thermodynamics and Molecular Structure
- Rare-earth and actinide compounds
- Calcium Carbonate Crystallization and Inhibition
- X-ray Diffraction in Crystallography
- Planetary Science and Exploration
- Glass properties and applications
Institut de minéralogie, de physique des matériaux et de cosmochimie
2011-2024
Sorbonne Université
2011-2024
Centre National de la Recherche Scientifique
2011-2024
Institut de Recherche pour le Développement
2018-2021
Synchrotron soleil
2016-2019
John Wiley & Sons (United States)
2019
Charles River Laboratories (Netherlands)
2019
École Normale Supérieure de Lyon
2016
Université Claude Bernard Lyon 1
2016
Laboratoire de Géologie de Lyon : Terre, Planètes et Environnement
2016
The global geochemical carbon cycle involves exchanges between the Earth’s interior and surface. Carbon is recycled into mantle via subduction mainly as carbonates released to atmosphere volcanism mostly CO 2 . stability of versus decarbonation melting therefore great interest for understanding cycle. For all these reasons, thermodynamic properties phase diagrams minerals are needed up core boundary conditions. However, nature C-bearing at conditions remains unclear. Here we show existence a...
The fate of carbonates in the Earth's mantle plays a key role geodynamical carbon cycle. Although iron is major component lower mantle, stability Fe‐bearing has rarely been studied. Here we present experimental results on Fe‐rich at pressures ranging from 40 to 105 GPa and temperatures 1450–3600 K, corresponding depths within about 1000–2400 km. Samples oxides iron‐magnesium were loaded into CO 2 gas laser heated diamond‐anvil cell. nature crystalline run products was determined situ by...
Abstract As the main constituent of planetary cores, pure iron phase diagram under high pressure and temperature is fundamental importance in geophysics science. However, previously reported iron‐melting curves show large discrepancies (up to 1000 K at Earth's core–mantle boundary, 136 GPa), resulting persisting uncertainties on solid‐liquid boundary. Here we unambiguously that observed differences commonly attributed nature used melting diagnostic are due a carbon contamination sample as...
PSICHE (Pressure, Structure and Imaging by Contrast at High Energy) is the high-energy beam line of SOLEIL synchrotron. The designed to study samples extreme pressures, using diffraction, perform imaging tomography for materials science other diverse applications. This paper presents tomograph use imaging, with emphasis on developments made respect existing instruments. Of particular note are high load capacity rotation stage free central aperture installing large or complex sample...
Carbonates are the main species that bring carbon deep into our planet through subduction. They an important rock-forming mineral group, fundamentally distinct from silicates in Earth's crust binds to three oxygen atoms, while silicon is bonded four oxygens. Here we present experimental evidence under sufficiently high pressures and temperatures existing lower mantle, ferromagnesian carbonates transform a phase with tetrahedrally coordinated carbons. Above 80 GPa, situ synchrotron infrared...
Physical properties of liquid Fe-S alloys (from 10 to 50 at%S) under high pressure were investigated by in situ X‑ray diffraction (up 5 GPa and 1900 K) ab initio calculations. The local structure clearly shows how S modifies the arrangement Fe atoms. Density has been extracted from diffuse scattering minimization oscillation short distance radial distribution function g(r). Two different formalisms for P-V-T-X equation state are presented model density sound velocity as a pressure,...
Abstract The density and structure of liquid Fe‐C alloys have been measured up to 58 GPa 3,200 K by in situ X‐ray diffraction using a Paris‐Edinburgh press laser‐heated diamond anvil cell. Study the pressure evolution local inferred measurements is important understand compression mechanism liquid. Obtained data show that degree greater for first coordination sphere than second third spheres. extrapolation suggests carbon cannot be only light element alloyed iron Earth's core, as 8–16 at % C...
Abstract The MESSENGER mission revealed that Mercury's magnetic field might have operated since 3.7–3.9 Ga. While the intrinsic magnetism suggests an active dynamo within core, mechanism is responsible for sustaining prolonged period of time remains unknown. Here we investigated electrical conductivity Fe‐S alloys at pressure 8 GPa and temperatures up to 1,700 K. We show 1,500 K about 10 3 S/m, 2 orders magnitude lower than previously assumed value calculations. thermal was estimated using...
Abstract The elasticity of hcp‐Fe‐5wt%Si has been investigated by synchrotron X‐ray diffraction up to 110 GPa and 2,100 K picosecond acoustics measurements at ambient temperature 115 GPa. established Pressure‐Volume‐Temperature equation state shows that the density Earth's inner core can be matched an Fe‐Si alloy with 5wt% Si for all reasonable temperatures, but its compressional shear velocities remain too high respect seismological observations. On other hand, alloys whose are expected get...
FeO represents an important end-member for planetary interiors mineralogy. However, its properties in the liquid state under high pressure are poorly constrained. Here, situ high-pressure and high-temperature X-ray diffraction experiments, ab initio simulations, thermodynamic calculations combined to study local structure density evolution of extreme conditions. Our results highlight a strong shortening Fe-Fe distance, particularly pronounced between ambient ∼40 GPa, possibly related with...
We have implemented an in situ X-ray diffraction analysis method suitable for the determination of pressure–volume–temperature equations state critical case liquid and amorphous materials over extended thermodynamic range (T>2000 K P>40 GPa). This is versatile, it can be applied to data obtained using various angle-dispersive high pressure apparatus and, contrary absorption techniques, independent from sample geometry. Further advantage fast acquisition (between 10 300 s integration time)....
Recent experiments have demonstrated the existence of previously unknown iron oxides at high pressure and temperature including newly discovered pyrite-type FeO2 FeO2Hx phases stable deep terrestrial lower mantle pressures temperatures. In present study, we probed oxidation state in high-pressure transformation products Fe3+OOH goethite by situ X-ray absorption spectroscopy laser-heated diamond-anvil cell. At temperatures ~91 GPa 1,500-2,350 K, respectively, that is, reported stability field...
Abstract X-ray absorption spectroscopy (XAS) is a widely used technique to probe the local environment around specific atomic species. Applied samples under extreme pressure and temperature conditions, XAS sensitive phase transitions, including melting, allows gathering insights on compositional variations electronic changes occurring during such transitions. These characteristics can be exploited for studies of prime interest in geophysics fundamental high-pressure physics. Here, we...
Abstract The high‐pressure behavior of manganese‐rich carbonate, rhodochrosite, has been characterized up to 62 GPa by synchrotron‐based midinfrared spectroscopy and X‐ray diffraction. Modifications in both the infrared spectra diffraction patterns were observed above ~35 GPa, indicating presence a phase transition at these pressures. We found that rhodochrosite adopts structure close CaCO 3 ‐VI with triclinic unit cell ( = 2.87 Å, b 4.83 c 5.49 α 99.86°, β 94.95°, γ 90.95° GPa). Using...
Atmospheric carbon is critical for maintaining the climate and life equilibrium on Earth. The concentration of this controlled by deep cycle, which responsible billion year-scale evolution terrestrial reservoirs planet. Understanding crystal chemistry physical properties carbonates at mantle conditions vital as they represent main oxidized carbon-bearing phases in Earth's mantle. Here we present data rhodochrosite high pressure.
Using a combination of picosecond acoustics and synchrotron x-ray diffraction, the sound velocities equations state Fe-Si alloys have been determined over wide range compositions (10--29 at. % Si) pressures (up to 65 GPa) under quasihydrostatic conditions. We observe marked variation in elastic properties depending on synthesis method degree Si ordering. In particular, it is observed that there sharp change density dependence which coincides with observation long-range ordering by...
In situ microtomography at high pressure and temperature has developed rapidly in the last decade, driven by development of new high-pressure apparatus. It is now routinely possible to characterize material under with acquisition times for tomograms order tens minutes. Here, advantage was taken possibility combine use a pink beam projected through standard Paris-Edinburgh press demonstrate perform high-speed synchrotron X-ray tomography allowing complete high-resolution be acquired about 10...
Abstract Volatiles, such as carbon and water, modulate the Earth's mantle rheology, partial melting redox state, thereby playing a crucial role in internal dynamics. We experimentally show transformation of goethite FeOOH presence CO2 into tetrahedral carbonate phase, Fe4C3O12, at conditions above 107 GPa—2300 K. At temperatures below 2300 K, no interactions are evidenced between CO2, instead pyrite-structured FeO2Hx is formed recently reported by Hu et al. (2016; 2017) Nishi (2017). The...
Research Article| January 01, 2013 Nanoprobes for Deep Carbon Wendy L. Mao; Mao Department of Geological and Environmental Sciences, Stanford University, Stanford, California 94305-2115, U.S.A., wmao@stanford.edu, boulard@stanford.edu Search other works by this author on: GSW Google Scholar Eglantine Boulard Reviews in Mineralogy Geochemistry (2013) 75 (1): 423–448. https://doi.org/10.2138/rmg.2013.75.13 Article history first online: 09 Mar 2017 Cite View This Citation Add to Manager Share...
X-ray computed microtomography (XCT) has been a very promising and exciting technique for high pressure (HP) science since the introduction of first HP setups optimized tomography in mid-2000s. Different experimental stations are now available using diamond anvil cells (DACs) or large volume presses, with their own benefits limitations: access to pressures but at room temperature on one hand, (HT) moderate other, slow acquisitions being an undesired common point between all techniques. We...