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Proton diffusion mechanism in amorphous SiO2

Publications associées (29)

Local vs. cooperative: Unraveling glass transition mechanisms with SEER

Which phenomenon slows down the dynamics in supercooled liquids and turns them into glasses is a long-standing question of condensed matter. Most popular theories posit that as the temperature decreases, many events must occur in a coordinated fashion on a ...

National Academy of Sciences2024

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

Optimization of composition and structure of cemented carbide cutting tools

Samy Adjam

WC-Co cemented carbides are composites, which combine a hard phase consisting of WC grains and a metallic ductile phase as a binder. Their excellent mechanical properties, combining high hardness, toughness and refractory properties, make them excellent ma ...

EPFL2021

Archetypal Soft-Mode-Driven Antipolar Transition in Francisite Cu3Bi(SeO3)(2)O2Cl

Helmuth Berger

Model materials are precious test cases for elementary theories and provide building blocks for the understanding of more complex cases. Here, we describe the lattice dynamics of the structural phase transition in francisite Cu3Bi(SeO3)(2)O2Cl at 115 K and ...

2020

Thermal spin crossover in Fe(ii) and Fe(iii). Accurate spin state energetics at the solid state

Sergio Vela Llausi, Maria Fumanal Quintana

The thermal spin crossover (SCO) phenomenon refers to an entropy-driven spin transition in some materials based on d(6)-d(9) transition metal complexes. While its molecular origin is well known, intricate SCO behaviours are increasingly common, in which th ...

ROYAL SOC CHEMISTRY2020

Magnetic dynamics across the in-field transition in Ca3Co2O6

Arnaud Magrez, Henrik Moodysson Rønnow, Ivica Zivkovic, Nagabhushan Ganesh Hegde

The discovery of multiple coexisting magnetic phases in the crystallographically homogeneous compound Ca3Co2O6 has stimulated ongoing research activity. In recent years the main focus has been on the zero-field-state properties, where exceedingly long time ...

AMER PHYSICAL SOC2020

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

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

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

Automated Multiscale Approach To Predict Self-Diffusion from a Potential Energy Field

Berend Smit, Senja Dominique Barthel, Amber Kashan Mace

For large-scale screening studies there is a need to estimate the diffusion of gas molecules in nanoporous materials more efficiently than (brute force) molecular dynamics. In particular for systems with low diffusion coefficients molecular dynamics can be ...

2019

Alignment of energy levels in amorphous oxides and at semiconductor-water interfaces

Zhendong Guo

We conduct a detailed investigation of defects in two representative amorphous oxides: amorphous Al2O3 (am-Al2O3) and TiO2 (am-TiO2), by combining ab initio molecular dynamics (MD) simulations and hybrid functional calculations. Our results indicate that o ...

EPFL2019

Comparing dynamics: deep neural networks versus glassy systems

Mario Geiger, Matthieu Wyart, Stefano Spigler, Levent Dogus Sagun, Marco Baity-Jesi

We analyze numerically the training dynamics of deep neural networks (DNN) by using methods developed in statistical physics of glassy systems. The two main issues we address are (1) the complexity of the loss landscape and of the dynamics within it, and ( ...

IOP PUBLISHING LTD2019

Spatio-temporal observation of dynamical structures in order-disorder phenomena and phase transitions via Ultrafast Electron Diffraction

Francesco Pennacchio

The development of ultrafast time-resolved techniques in the last decades allowed the direct observation of out-of-equilibrium transient states and dynamical processes up to then hidden in many different fields, ranging from chemistry to solid state physic ...

EPFL2018

Comparing Dynamics: Deep Neural Networks versus Glassy Systems

Rainer Wesche, Mario Geiger, Stefano Spigler, Levent Dogus Sagun, Marco Baity-Jesi

We analyze numerically the training dynamics of deep neural networks (DNN) by using methods developed in statistical physics of glassy systems. The two main issues we address are the complexity of the loss-landscape and of the dynamics within it, and to wh ...

2018

Synthetic spectra of BeH, BeD and BeT for emission modeling in JET plasmas

Patrick Blanchard, Basil Duval, Ambrogio Fasoli, Yves Martin, Richard Pitts, Olivier Sauter, Henri Weisen, Robin Humphry-Baker, Stefano Coda, Martinus Gijs, Partha Dutta, Marco Wischmeier, Jan Horacek, Vlad Trifa, Yann Camenen, Jonathan Graves, Duccio Testa, Miguel Fernández Ruiz, Sun Hee Kim, Mikhail Maslov, Javier García Hernández, David Pfefferlé, José Pedro Rebelo Ferreira Marques, Julio Rodriguez, Pedro Camilo de Oliveira e Silva, Rebecca Hill, Daniel Scott Alessi, Jonnathan Cesar Hidalgo Acosta, Ana Francisca Leal Silva Soares, Dalziel Joseph Wilson, Pierre-Thomas Paul Brun, Jonathan Marc Philippe Faustin, Federico Nespoli, Alberto Hernando de Castro, Hamish William Patten, Bruno Emanuel Ferreira De Sousa Correia, Li Shuai, Nicola Vianello, Antonio José Pereira de Figueiredo, Samuel Lanthaler, Liang Yao, Arnout Lodewijk M Beckers, Cristian Sommariva, Davide Galassi, Alessandro Pau, Yao Zhou, Otto Asunta, Bernhard Sieglin

A theoretical model for isotopologues of beryllium monohydride, BeH, BeD and BeT, A (2)Pi to X (2)Sigma(+) visible and X (2)Sigma(+) to X (2)Sigma(+) infrared rovibronic spectra is presented. The MARVEL procedure is used to compute empirical rovibronic ene ...

IOP Publishing2018

Intrinsic structural transitions of the pyramidal I 〈c+a〉 dislocation in magnesium

William Curtin, Zhaoxuan Wu

The stability of a mixed < c + a > dislocation on the pyramidal I plane in magnesium is studied using molecular dynamics simulations. The dislocation is metastable and undergoes a thermally-activated transition to either a sessile, basal-dissociated < c + ...

Elsevier2016

Ice VII from aqueous salt solutions: From a glass to a crystal with broken H-bonds

Livia Eleonora Bove Kado

It has been known for decades that certain aqueous salt solutions of LiCl and LiBr readily form glasses when cooled to below approximate to 160 K. This fact has recently been exploited to produce a "salty" high-pressure ice form: When the glass is compress ...

Nature Research2016

Effects of Zeolite Structural Confinement on Adsorption Thermodynamics and Reaction Kinetics for Monomolecular Cracking and Dehydrogenation of n-Butane

Berend Smit

The effects of zeolite structure on the kinetics of n-butane monomolecular cracking and dehydrogenation are investigated for eight zeolites differing in the topology of channels and cages. Monte Carlo simulations are used to calculate enthalpy and entropy ...

American Chemical Society2016

Spin and orbital disordering by hole doping in Pr1-xCaxVO3

Philip Pattison

High-resolution powder x-ray diffraction and single-crystal neutron diffraction were used to investigate the crystal structure and magnetic ordering of the compound Pr1-xCax VO3 (0

Amer Physical Soc2016

Assessment of phase-field-crystal concepts using long-time molecular dynamics

William Curtin, Kristopher Learion Baker

The ability of the phase-field-crystal (PFC) model to quantitatively predict atomistic defect structures in crystalline solids is addressed. First, general aspects of the PFC model are discussed within the context of obtaining quantitative results in solid ...

American Physical Society2015

Catalytic Metal Ions and Enzymatic Processing of DNA and RNA

Matteo Dal Peraro, Giulia Palermo, Andrea Cavalli

Two-metal-ion-dependent nucleases cleave the phosphodiester bonds of nucleic acids via the two-metal-ion (2M) mechanism. Several high-resolution X-ray structures portraying the two-metal-aided catalytic site, together with mutagenesis and kinetics studies, ...

Amer Chemical Soc2015