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Concept

Olivine

Publications associées (27)

Mapping orthorhombic domains with geometrical phase analysis in rare-earth nickelate heterostructures

Duncan Thomas Lindsay Alexander, Bernat Mundet

Most perovskite oxides belong to the Pbnm space group, composed of an anisotropic unit cell, A-site antipolar displacements, and oxygen octahedral tilts. Mapping the orientation of the orthorhombic unit cell in epitaxial heterostructures that consist of at ...

Aip Publishing2024

Micromechanics of oxide inclusions in ferrous alloys

Alejandra Inés Slagter

Oxide inclusions are inevitably present in steel as a direct consequence of the steelmaking process; as a result, a cubic centimetre of modern steel will generally contain about a million of these hard and brittle micrometre-sized ceramic particles. Inclus ...

EPFL2023

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

Hui Chen, Hui Chen

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

The role of Zn in C-S-H atomic structure, nucleation and growth

Anna Morales Melgares

The most promising solution towards cementitious materials with a lower carbon footprint is the partial substitution of the clinker by supplementary cementitious materials (SCMs) such as fly ash, blast furnace slag, limestone and calcined clays. The produc ...

EPFL2023

A method for the reliable and reproducible precipitation of phase pure high Ca/Si ratio (>1.5) synthetic calcium silicate hydrates (C-S-H)

Karen Scrivener, Paul Bowen, Maya Nicole Harris

Various methods have been developed to synthesize C-S-H; however, these methods have only allowed for the successful production of pure-phase C-S-H with Ca:Si of 1.5 or less. Attempts to form higher Ca:Si ratios by these methods gives C-S-H (Ca:Si 1.5 or l ...

Pergamon-Elsevier Science Ltd2022

Electron probing of oxygen-evolving oxide catalysts

Tzu-Hsien Shen

Water splitting is one of the cleanest ways to store energy. The production of hydrogen and oxygen gases can be utilized in fuel cells to generate electricity, power, and heat. In the water splitting process, the oxygen evolution reaction (OER), taking pla ...

EPFL2022

Neural Network Potentials for Age Hardening Aluminum Alloys

Daniel John Gilles Marchand

High-strength metal alloys achieve their performance via careful control of precipitates and solutes. The nucleation, growth, and kinetics of precipitation, and the resulting mechanical properties, are inherently atomic scale phenomena, particularly during ...

EPFL2022

Effect of alkali hydroxide on calcium silicate hydrate (C-S-H)

Karen Scrivener, Émilie Michèle L'Hôpital, Yu Yan

This paper investigates the effect of KOH and NaOH on C-S-H structure and solubility. Both KOH and NaOH have a similar effect, they increase pH values and silicon concentrations, and decrease calcium concentrations. At higher alkali hydroxide concentration ...

Pergamon-Elsevier Science Ltd2022

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

Synthesis, structural and magnetic characterization of thin films of the chiral magnets CoZnMn and FeGe

Anna Kúkol'ová

Skyrmions are topologically protected nanometer-sized magnetic vortices that have sparked interest for future spintronics applications aiming at high-density, high-speed and low-power consuming magnetic memory devices. One type of skyrmions appears in non- ...

EPFL2021

Iron incorporation in synthetic precipitated calcium silicate hydrates

David Lyndon Emsley, Paul Bowen, Brennan James Walder, Jirawan Siramanont

Effect of Fe3+ on the precipitation of synthetic calcium silicate hydrates (C-S-H) under controlled conditions has been evaluated. Using extremely basic either initial calcium nitrate or sodium silicate solutions (pH > 11), incipient formation of ferrihydr ...

Pergamon-Elsevier Science Ltd2021

Oxygen Evolution Reaction in Ba0.5Sr0.5Co0.8Fe0.2O3-delta Aided by Intrinsic Co/Fe Spinel-Like Surface

Vasiliki Tileli, Tzu-Hsien Shen, Thi Ha My Pham, Jan Vávra

Among the perovskites used to catalyze the oxygen evolution reaction (OER), Ba0.5Sr0.5Co0.8Fe0.2O3-delta (BSCF) exhibits excellent activity which is thought to be related to dynamic reconstruction at the flexible perovskite surface due to accommodation of ...

AMER CHEMICAL SOC2020

Deciphering Iron-Dependent Activity in Oxygen Evolution Catalyzed by Nickel-Iron Layered Double Hydroxide

Xile Hu, Lichen Bai, Seunghwa Lee

Nickel iron oxyhydroxide is the benchmark catalyst for the oxygen evolution reaction (OER) in alkaline medium. Whereas the presence of Fe ions is essential to the high activity, the functions of Fe are currently under debate. Using oxygen isotope labeling ...

Wiley-VCH Verlag GmbH2020

Essential role of oxygen vacancies of Cu-Al and Co-Al spinel oxides in their catalytic activity for the reverse water gas shift reaction

Ursula Röthlisberger, Jeremy Luterbacher, Oliver Kröcher, Pascal Alexander Schouwink, Florent Emmanuel Héroguel, Alimohammad Bahmanpour, Christophe Jean Baranowski, Murat Kiliç

CO2 catalytic hydrogenation to CO will likely be an important part of CO2 mitigation and valorization processes. Recently, we have developed materials containing surface-formed Cu-Al spinel that act as active and stable catalysts for this reaction. Here, t ...

2020

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

An alternative model for the formation of hydrous Mg/Ni layer silicates ("deweylite"/"garnierite") in faulted peridotites of New Caledonia: II. Petrography and chemistry of white and green clay infillings

Gabrielle Dublet

This study, which complements a first mineralogical work, presents detailed petrographic and chemical data on the sequences of clay infillings commonly found in serpentine veins of reactivated faults from the New Caledonian peridotite formation. Chemical t ...

E SCHWEIZERBARTSCHE VERLAGSBUCHHANDLUNG2019

Tuning the Incorporation of Magnesium into Calcite during Its Crystallization from Additive-Free Aqueous Solution

Esther Amstad, Huachuan Du

Under ambient conditions, marine organisms are able to synthesize a variety of functional materials, ranging from eye lenses to protective shells through the meticulous control over magnesium incorporation into calcite during its crystallization. The mecha ...

AMER CHEMICAL SOC2019

Impact of temperature on expansive behavior of concrete with a highly reactive andesite due to the alkali-silica reaction

Karen Scrivener, Cyrille Dunant

The influence of temperature on the expansive behavior and microstructural damage of concrete due to the alkali-silica reaction (ASR) is studied experimentally by applying a new testing protocol, the Alkali-Wrapped Concrete Prism Test (AW-CPT). Early-stage ...

Pergamon-Elsevier Science Ltd2019

Magnesium Partitioning Between Earth's Mantle and Core and its Potential to Drive an Early Exsolution Geodynamo

James Badro

Magnesium partitioning between metal and silicate was experimentally investigated between 34 and 138GPa, 3,500 and 5,450K using laser-heated diamond anvil cells. The 22 measurements are combined with previously published data (total of 49 measurements) to ...

AMER GEOPHYSICAL UNION2018