A5028743151- High-pressure geophysics and materials
- Geological and Geochemical Analysis
- earthquake and tectonic studies
- Astro and Planetary Science
- Diamond and Carbon-based Materials Research
- Microstructure and Mechanical Properties of Steels
- Planetary Science and Exploration
- Geomagnetism and Paleomagnetism Studies
- Laser-induced spectroscopy and plasma
- Metallurgical Processes and Thermodynamics
- X-ray Diffraction in Crystallography
- X-ray Spectroscopy and Fluorescence Analysis
- Nuclear Physics and Applications
- Crystal Structures and Properties
- Chemical Thermodynamics and Molecular Structure
- Metallurgy and Cultural Artifacts
- Material Properties and Failure Mechanisms
- Intermetallics and Advanced Alloy Properties
- Thermodynamic and Structural Properties of Metals and Alloys
- Advanced X-ray Imaging Techniques
- Metallic Glasses and Amorphous Alloys
- Material Dynamics and Properties
- Hydrocarbon exploration and reservoir analysis
- Stellar, planetary, and galactic studies
- Rare-earth and actinide compounds
Université Savoie Mont Blanc
2020-2025
Université Grenoble Alpes
2020-2025
Institut des Sciences de la Terre
2020-2025
Sorbonne Université
2015-2024
Centre National de la Recherche Scientifique
2015-2024
Institut de minéralogie, de physique des matériaux et de cosmochimie
2015-2024
Université Gustave Eiffel
2020-2024
Institut de Recherche pour le Développement
2015-2024
University of Edinburgh
2023-2024
Université Sorbonne Nouvelle
2023
Earth's core is structured in a solid inner core, mainly composed of iron, and liquid outer core. The temperature at the boundary expected to be close melting point iron 330 gigapascal (GPa). Despite intensive experimental theoretical efforts, there little consensus on behavior these extreme pressures temperatures. We present static laser-heated diamond anvil cell experiments up 200 GPa using synchrotron-based fast x-ray diffraction as primary diagnostic. When extrapolating higher pressures,...
Using ab initio molecular dynamics simulations, we calculate the equation of state iron in solid phase for both hcp and bcc structures as well high-pressure melting curve up to 15 Mbars. We first find that temperature increases 11 000 K at highest pressures investigated following a semiempirical law over entire pressure domain. also investigate stability beyond Earth's core conditions (3 Mbars) which is mechanically stabilized with density. Finally, provide simple fits these results...
The density of liquid iron has been determined up to 116 GPa and 4350 K via static compression experiments following an innovative analysis diffuse scattering from liquid. longitudinal sound velocity was also obtained 45 2700 based on inelastic x-ray measurements. Combining these results with previous shock-wave data, we determine a thermal equation state for iron. It indicates that Earth's outer core exhibits 7.5%–7.6% deficit, 3.7%–4.4% excess, almost identical adiabatic bulk modulus,...
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...
We present an overview of some recent theoretical and experimental results obtained on the properties iron silica at conditions encountered in planetary interiors. The first part is concerned with development x-ray absorption near edge spectroscopy dynamical experiments using high-energy lasers as a tool to investigate phase transitions structural changes extreme pressure–temperature for these two key constituents. second focuses quasi-isentropic compression technique achieve anticipated...
Significance Iron is the main constituent of terrestrial planetary cores, taking on a hexagonal closed packed structure under conditions Earth’s inner core, and face-centered cubic (fcc) at more moderate pressures smaller bodies, such as Moon, Mercury, or Mars. Here we present sound velocity density measurements fcc iron temperatures characteristic small interiors. The results indicate that seismic velocities currently proposed for Moon’s core are well below those plausible alloys. Our...
We report an experimental study of the phase diagrams periclase (MgO), enstatite (MgSiO3) and forsterite (Mg2SiO4) at high pressures. investigated with laser driven decaying shocks pressure/temperature curves MgO, MgSiO3 Mg2SiO4 between 0.2-1.2 TPa, 0.12-0.5 TPa 0.2-0.85 respectively. A melting signature has been observed in MgO 0.47 9860 K, while no changes were neither nor Mg2SiO4. An increasing reflectivity liquids have detected 0.55 -12 760 0.15 - 7540 0.2 5800 In contrast to SiO2,...
Abstract Melting experiments were performed on the Fe‐C‐H system to 127 GPa in a laser‐heated diamond anvil cell. On basis of situ and ex sample characterizations, we found that solubility carbon liquid Fe correlates inversely with hydrogen concentration at ~60 ~3500 K, indicating preferentially incorporates rather than under conditions abundant C H. While large amounts both H may have been delivered growing Earth, C‐poor/H‐rich metals likely added protocore late stages core formation. We...
Mercury's metallic core is expected to have formed under highly reducing conditions, resulting in the presence of significant quantities silicon alloyed iron. Here we present phase diagram Fe-FeSi system, reconstructed from situ X-ray diffraction measurements at pressure and temperature conditions spanning over those for core, ex chemical analysis recovered samples. Under high pressure, do not observe a miscibility gap between cubic fcc B2 structures, but rather formation re-entrant bcc...
The pyrolite model is one of the possible compositions Earth's lower mantle. mantle's composition generally modelled by comparing seismic observations with mineral physics data mantle end‐member phases. Here, we report compression behavior a natural KLB‐1 peridotite (a representative model) in quasi‐hydrostatic environment at simultaneous high pressure (P) and temperature (T), covering entire range P‐T conditions up to 112 GPa. This first experimentally determined density profile under...