Publications associées à Fusion (physique)

Identification and thermal healing of focused ion beam-induced defects in GaN using off-axis electron holography

Nicolas Grandjean, Jean-François Carlin, Raphaël Butté, Yi Wang

Thermal healing of focused ion beam-implanted defects in GaN is investigated by off-axis electron holography in TEM. The data reveal that healing starts at temperatures as low as about 250 degrees C. The healing processes result in an irreversible transiti ...

Iop Publishing Ltd2024

Shaped Laser Pulses for Microsecond Time-Resolved Cryo-EM: Outrunning Crystallization during Flash Melting

Marcel Drabbels, Ulrich Lorenz, Constantin Richard Krüger, Nathan Junior Mowry

Water vitrifies if cooled at rates above 3 × 105 K/s. In contrast, when the resulting amorphous ice is flash heated, crystallization occurs even at a more than 10 times higher heating rate, as we have recently shown. This may present an issue for microseco ...

2024

Flash Melting Amorphous Ice

Marcel Drabbels, Ulrich Lorenz, Constantin Richard Krüger, Gabriele Bongiovanni, Nathan Junior Mowry

Water can be vitrified if it is cooled at high rates, which makes it possible to outrun crystallization in so-called no man’s land, a range of deeply supercooled temperatures where water crystallizes rapidly. Here, we study the reverse process in pure wate ...

2024

A thermotropic liquid crystal enables efficient and stable perovskite solar modules

Mohammad Khaja Nazeeruddin, Yong Ding, Bin Ding, Cheng Liu, Jian Xu

Perovskite solar cells have seen impressive progress in performance and stability, yet maintaining efficiency while scaling area remains a challenge. Here we find that additives commonly used to passivate large-area perovskite films often co-precipitate du ...

Nature Portfolio2024

Microsecond time-resolved cryo-electron microscopy

Ulrich Lorenz

Microsecond time-resolved cryo-electron microscopy has emerged as a novel approach for directly observing protein dynamics. By providing microsecond temporal and near-atomic spatial resolution, it has the potential to elucidate a wide range of dynamics tha ...

2024

A hybrid Selective Laser Sintering based process for the additive manufacturing of architectured composites

Erwan Philippe Guenier

Additive Manufacturing also commonly referred as 3D printing has been given a lot of interest lately. Market is growing exponentially and the aim for obtaining more complex and ready-to use parts is emerging. All the 3D printing processes consist in buildi ...

EPFL2023

Crystalline or amorphous? A critical evaluation of phenomenological phase selection rules

Johann Michler, Caroline Hain, Ashish Sharma

In this work, we reviewed the available phase selection rules comprising atomic size and topological aspects, entropies, enthalpies, melting points, valence and itinerant electron concentrations, as well as electronegativity, and validated them using a car ...

ELSEVIER SCI LTD2023

Deposition freezing, pore condensation freezing and adsorption: three processes, one description?

Athanasios Nenes, Mária Lbadaoui-Darvas

Heterogeneous ice nucleation impacts the hydrological cycle and climate through affecting cloud microphysical state and radiative properties. Despite decades of research, a quantitative description and understanding of heterogeneous ice nucleation remains ...

Copernicus GmbH2023

Growth and investigation of Argon thin films adsorbed on graphite by means of Ultrafast Electron Diffraction

Paolo Usai

Starting from our big universe to the microscopic world, phase transitions play an important role in nature. Just after the Big Bang our universe experienced multiple phase transitions, from high-temperature plasma to the matter we know today. Phase transi ...

EPFL2023

A universal signature in the melting of metallic nanoparticles

Kevin Rossi

Predicting when phase changes occur in nanoparticles is fundamental for designing the next generation of devices suitable for catalysis, biomedicine, optics, chemical sensing and electronic circuits. The estimate of the temperature at which metallic nanopa ...

ROYAL SOC CHEMISTRY2021

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

Philippe Gillet, Cécile Hébert, Marco Cantoni, James Badro, Farhang Nabiei, 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

Kibble-Zurek exponent and chiral transition of the period-4 phase of Rydberg chains

Frédéric Mila, Natalia Chepiga

Chains of Rydberg atoms have emerged as an amazing playground to study quantum physics in 1D. Playing with inter-atomic distances and laser detuning, one can in particular explore the commensurate-incommensurate transition out of density waves through the ...

Nature Research2021

Understanding Thermomechanical Treatments Induced by Laser Powder Bed Fusion Process

Hossein Ghasemi Tabasi

Additive Manufacturing (AM) is referred to technologies that produce directly 3D parts in a layer-by-layer fashion. Laser Powder Bed Fusion (L-PBF) is one of the most important AM processes, enabling production of very complex metallic objects from a compu ...

EPFL2021

Secondary ice production in summer clouds over the Antarctic coast: an underappreciated process in atmospheric models

Athanasios Nenes, Alexis Berne, Georgia Sotiropoulou, Etienne Gabriel Henri Vignon

The correct representation of Antarctic clouds in atmospheric models is crucial for accurate projections of the future Antarctic climate. This is particularly true for summer clouds which play a critical role in the surface melting of the ice shelves in th ...

European Geosciences Union2021

Simulating Infiltration as a Sequence of Pinning and De-pinning Processes

Andreas Mortensen, William Craig Carter

The infiltration of a non-wetting liquid, such as molten metal, into a porous solid, such as a ceramic preform, is influenced by the wetting angle of the liquid on the solid. The link between local wetting and the minimum pressure required for initiation o ...

2021

Superconducting 2D NbS2 Grown Epitaxially by Chemical Vapor Deposition

Aleksandra Radenovic, Andras Kis, Mukesh Kumar Tripathi, Michal Daniel Macha, Yanfei Zhao, Guilherme Migliato Marega, Zhenyu Wang, Cheol Yeon Cheon, Hyungoo Ji

Metallic two-dimensional (2D) transition metal dichalcogenides (TMDCs) are attracting great attention because of their interesting low-temperature properties such as superconductivity, magnetism, and charge density waves (CDW). However, further studies and ...

2021

A direct link between active matter and sheared granular systems

Elisabeth Agoritsas

The similarity in mechanical properties of dense active matter and sheared amorphous solids has been noted in recent years without a rigorous examination of the underlying mechanism. We develop a mean-field model that predicts that their critical behavior— ...

2021

Surface modified microfibrillated cellulose‐poly(vinylidene fluoride) composites: β‐phase formation, viscoelastic and dielectric performance

Véronique Michaud, Yves Leterrier, Dragan Damjanovic, Mohammed Arif Poothanari

The effect of silylation of microfibrillated cellulose (MFC) surfaces on β‐phase formation in poly(vinylidene difluoride) (PVDF) and the resulting viscoelastic and dielectric performance of MFC‐PVDF composites is investigated. Two different organosilanes, ...

2021

Thermal coarsening of individual titanate nanowires and their assemblies: Surface vs. bulk diffusion

László Forró, Luca Rossi, Endre Horvath, Sergiy Katrych, Massimo Spina, Laurent Syavoch Bernard, Xavier Berdat

The thermal coarsening of titanate nanowires was investigated from room temperature to 1000 degrees C by AFM, SEM, XRD and Raman spectroscopy. Phase transformation kinetics and the external morphology were studied in two configurations: i) as individual an ...

2020

Buoyancy-driven melting and solidification heat transfer analysis in encapsulated phase change materials

Sophia Haussener, Nithin Mallya

Controlled melting and solidification in encapsulated phase change materials (PCMs) is of practical interest, for example, in latent heat storage applications. The choice of PCMs and the dynamic heat transfer characteristics during phase change - affecting ...

2021