Publications de Farhang Nabiei

High Sodium Solubility in Magnesiowüstite in Iron-Rich Deep Lower Mantle

Marco Cantoni, Farhang Nabiei, James Badro

(Mg,Fe)O ferropericlase-magnesiow & uuml;stite has been proposed to host the majority of Earth's sodium, but the mechanism and capacity for incorporating the alkali cation remain unclear. In this work, experiments in the laser-heated diamond anvil cell and ...

Amer Geophysical Union2024

Non-negative matrix factorization-aided phase unmixing and trace element quantification of STEM-EDXS data

Cécile Hébert, Duncan Thomas Lindsay Alexander, Farhang Nabiei, James Badro

Energy-dispersive X-ray spectroscopy (EDXS) mapping with a scanning transmission electron microscope (STEM) is commonly used for chemical characterization of materials. However, STEM-EDXS quantification becomes challenging when the phases constituting the ...

Elsevier2024

Composition and Pressure Effects on Partitioning of Ferrous Iron in Iron-Rich Lower Mantle Heterogeneities

Marco Cantoni, Philippe Gillet, Farhang Nabiei, Susannah McGregor Dorfman, James Badro, Charles-Edouard Boukaré

Both seismic observations of dense low shear velocity regions and models of magma ocean crystallization and mantle dynamics support enrichment of iron in Earth’s lowermost mantle. Physical properties of iron-rich lower mantle heterogeneities in the modern ...

2021

Investigating Magma Ocean Solidification on Earth Through Laser‐Heated Diamond Anvil Cell Experiments

Marco Cantoni, Cécile Hébert, Philippe Gillet, Farhang Nabiei, James Badro, Charles-Edouard Boukaré

We carried out a series of silicate fractional crystallization experiments at lower mantle pressures using the laser-heated diamond anvil cell. Phase relations and the compositional evolution of the cotectic melt and equilibrium solids along the liquid lin ...

2021

Laser-induced densification of fused silica using spatially overlapping sub-30fs pulses

Yves Bellouard, Farhang Nabiei, Ya Cheng

Over the past several years, non-ablative femtosecond laser exposure with spatially overlapping (i.e., spatially cumulative) pulses has emerged as a key process in three-dimensional writing of patterns in bulk of dielectric substrates. When temporally non- ...

2020

Blocked radiative heat transport in the hot pyrolitic lower mantle

Farhang Nabiei, James Badro, Hélène Marie Piet

The heat flux across the core-mantle boundary (Q(CMB)) is the key parameter to understand the Earth's thermal history and evolution. Mineralogical constraints of the Q(CMB) require deciphering contributions of the lattice and radiative components to the th ...

ELSEVIER2020

Carbonate stability in the reduced lower mantle

Marco Cantoni, Philippe Gillet, Farhang Nabiei, Susannah McGregor Dorfman, James Badro

2018

A large planetary body inferred from diamond inclusions in a ureilite meteorite

Marco Cantoni, Cécile Hébert, Emad Oveisi, Philippe Gillet, Farhang Nabiei, James Badro, Teresa Katharina Dennenwaldt

Planetary formation models show that terrestrial planets are formed by the accretion of tens of Moon-to Mars-sized planetary embryos through energetic giant impacts. However, relics of these large proto-planets are yet to be found. Ureilites are one of the ...

Nature Research2018

From 2D to 3D Characterization of Materials Subjected to Extreme Pressure and Temperature Conditions

Farhang Nabiei

Planetesimal were the first planetary objects to form in the solar system, which later grew to make the proto-planets. Most of these bodies were differentiated as a result of internal heating. Several differentiated bodies have, then, been accreted followi ...

EPFL2017

Spin and valence dependence of iron partitioning in Earth's deep mantle

Marco Cantoni, Cécile Hébert, Philippe Gillet, Farhang Nabiei, James Badro, Hélène Marie Piet, Teresa Katharina Dennenwaldt

We performed laser-heated diamond anvil cell experiments combined with state-of-the-art electron microanalysis (focused ion beam and aberration-corrected transmission electron microscopy) to study the distribution and valence of iron in Earth's lower mantl ...

National Academy of Sciences2016

Toward Knowledge-Based Grain-Boundary Engineering of Transparent Alumina Combining Advanced TEM and Atomistic Modeling

Paul Bowen, Marco Cantoni, Michael Stuer, Cécile Hébert, Abhishek Tewari, Farhang Nabiei

Transition element dopants (e.g., Y, La) are commonly used as sintering aids in polycrystalline alumina ceramics, which segregate to the grain boundaries and control the grain-boundary mobility. However, due to the extremely thin (

Wiley-Blackwell2015

Segregation of anion (Cl−) impurities at transparent polycrystalline α-alumina interfaces

Paul Bowen, Marco Cantoni, Cécile Hébert, Abhishek Tewari, Farhang Nabiei

Small amounts of anion impurities (e.g. Cl), which are incorporated during the synthesis of ceramic powders, can affect the properties and microstructure of the final sintered ceramic. The effect of anion impurities is a little studied and poorly understoo ...

Elsevier Sci Ltd2014