Publications associées à Synthesis and equation of state of perovskites in the (Mg, Fe)(3)Al2Si3O12 system to 177 GPa

New tools for phase segmentation and denoising of analytical STEM data for enhanced chemical sensitivity, applied to Earth mantle research

This thesis is dedicated to developing innovative methodologies that improve elemental quantification in scanning transmission electron microscopy (STEM) using energy-dispersive X-ray spectroscopy (EDXS). The primary motivation stems from a geochemistry pr ...

EPFL2023

First-Principles Thermodynamics of CsSnI3

Nicola Marzari, Lorenzo Monacelli

CsSnI3 is a promising ecofriendly solution for energy harvesting technologies. It exists at room temperature in either a black perovskite polymorph or a yellow 1D double-chain, which irreversibly deteriorates in the air. In this work, we unveil the relativ ...

AMER CHEMICAL SOC2023

Anti-Jahn-Teller effect induced ultrafast insulator to metal transition in perovskite BaBiO3

Changpeng Lin, Ben Xu

The Jahn-Teller (JT) effect involves the ions M with a degenerate electronic state distorting the corner-sharing MO6 octahedra to lift the degeneracy, inducing strong coupling of electrons to lattice, and mediating the exotic properties in perovskite oxide ...

NATURE PORTFOLIO2022

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

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

In-line electronic and structural characterization of reactively sputtered Cu-Co-Mn black spinel oxides

Andreas Schueler, Anna Krammer, Maxime Lagier

Cu-Co-Mn spinel oxide thin films are deposited by reactive magnetron sputtering. The x-ray diffraction (XRD) spectrum suggests a nanocrystalline spinel film when sputtered at approximate to 465 degrees C. In-line scanning tunneling microscopy confirms nano ...

A V S AMER INST PHYSICS2021

A combined molecular dynamics and experimental study of two-step process enabling low-temperature formation of phase-pure α-FAPbI3

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ursula Röthlisberger, Ulf Anders Hagfeldt, Paramvir Ahlawat, Essa Awadh R Alharbi, Haizhou Lu

It is well established that the lack of understanding the crystallization process in a two-step sequential deposition has a direct impact on efficiency, stability, and reproducibility of perovskite solar cells. Here, we try to understand the solid-solid ph ...

2021

The Effects of Planetary and Stellar Parameters on Brittle Lithospheric Thickness

Marie Estelle Solange Violay, Michael Heap

The thicknesss of the brittle lithosphere—the outer portion of a planetary body that fails via fracturing— plays a key role in the geological processes of that body. The properties of both a planet and its host star can influence that thickness, and the po ...

2021

Vapor Transport Deposition of Methylammonium Iodide for Perovskite Solar Cells

Christophe Ballif, Quentin Thomas Jeangros, Cédric Bucher, Florent Sahli, Léo Duchêne, Björn Niesen, Aymeric Michel Schafflützel, Nathanaël Miaz, Quentin Jean-Marie Armand Guesnay, Niccolo Salsi

Vapor-based processes are promising options to deposit metal halide perovskite solar cells in an industrial environment due to their ability to deposit uniform layers over large areas in a controlled environment without resorting to the use of (possibly to ...

2021

Photo- and thermally-induced electronic and structural dynamics in perovskites and transition metal oxides

Oliviero Cannelli

In this thesis, we exploited optical and X-ray pump-probe methods in a synergistic approach to study the interplay of the electronic, spin and structural degrees of freedom in two class of complex systems relevant for solar energy conversion applications: ...

EPFL2021

Controlling PbI2 Stoichiometry during Synthesis to Improve the Performance of Perovskite Photovoltaics

Mohammad Khaja Nazeeruddin, Tom Theodorus Antonius Lummen, Vikas Kumar

Over the past decade, remarkable progress has advanced the field of perovskite solar cells to the forefront of thin film solar technologies. The stoichiometry of the perovskite material is of paramount importance as it determines the optoelectronic propert ...

2021

Cubic, hexagonal and tetragonal FeGex phases (x = 1, 1.5, 2): Raman spectroscopy and magnetic properties

Anna Fontcuberta i Morral, Dirk Grundler, Nicolas Tappy, Santhanu Panikar Ramanandan, Anna Kúkol'ová, Mirjana Dimitrievska

There is currently an emerging drive towards computational materials design and fabrication of predicted novel materials. One of the keys to developing appropriate fabrication methods is determination of the composition and phase. Here we explore the FeGe ...

2021

Effects of composition and pressure on electronic states of iron in bridgmanite

Arnaud Magrez, Philippe Gillet, Susannah McGregor Dorfman

Electronic states of iron in the lower mantle's dominant mineral, (Mg,Fe,Al)(Fe,Al,Si)O-3 bridgmanite, control physical properties of the mantle including density, elasticity, and electrical and thermal conductivity. However, the determination of electroni ...

MINERALOGICAL SOC AMER2020

Increased nickel exsolution from LaFe0.8Ni0.2O3 perovskite-derived CO2 methanation catalysts through strontium doping

Oliver Kröcher, Davide Ferri, Patrick Simon Steiger

Perovskite-derived Ni catalysts offer the remarkable benefit of redox stability that allows their regeneration after deactivation through poisoning or Ni particle growth. Here, the catalytic activity of LaFe0.8Ni0.2O3 towards CO2 methanation was improved b ...

ELSEVIER2020

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

Mn4+-Substituted Li-Rich Li1.2Mn0.43+Mnx4+Ti0.4-xO2 Materials with High Energy Density

Yong Yang, Chunyang Zhang

In this work, Li-rich Li1.2Mn0.43+Mnx4+Ti0.4-xO2 (LMMxTO, 0

2020

The Role of Goldschmidt's Tolerance Factor in the Formation of A(2)BX(6) Double Halide Perovskites and its Optimal Range

Mohammad Khaja Nazeeruddin, Tom Theodorus Antonius Lummen, Nikita Drigo, Alexander Fedorovskiy

Vacancy-ordered double perovskites is a new branch of lead-free halide perovskites with properties promising for photovoltaic application. In this study, data about the crystal structure of 170 known A(2)BX(6) (X = I, Br, Cl, F) are collected and analyzed ...

2020

Combined synchrotron x-ray diffraction and NV diamond magnetic microscopy measurements at high pressure

Charles Michel Henri Pépin, Margarita Lesik Gaussens, Mayeul Sylvain Chipaux

We report the possibility to simultaneously perform wide-field nitrogen-vacancy (NV) diamond magnetic microscopy and synchrotron x-ray diffraction measurements at high pressure. NV color centers are created on the culet of a diamond anvil which is integrat ...

2020

A New Reference for the Thermal Equation of State of Iron

James Badro

The high-pressure, high-temperature behavior of iron was investigated to 140 GPa and 3500 K with in situ synchrotron X-ray diffraction. Iron samples were compressed in diamond-anvil cells and heated up with the double-sided laser-heating system installed a ...

MDPI2020

Ab Initio Molecular Dynamics Investigation of Molten Fe-Si-O in Earth's Core

James Badro

Silicon and oxygen are potential light elements in Earth's core because their stronger affinity to metal observed with increasing temperature posits that significant amounts of both can be incorporated into the core. It was proposed that an Fe-Si-O liquid ...

AMER GEOPHYSICAL UNION2019