Publications related to Atomic diffusion

Morphology and Transport Characterization of Catalyst Layers for CO2 Reduction

Gas diffusion electrodes (GDEs) help to reduce transport limitations in devices for electrochemical CO2 reduction. Homogenized modeling of such devices requires input of morphological characteristics and effective transport properties of the porous structu ...

2023

Diffusion on Demand to Control Precipitation Aging: Application to Al-Mg-Si Alloys

William Curtin, Michael Frederick Francis

We demonstrate experimentally that a part-per-million addition of Sn solutes in Al-Mg-Si alloys can inhibit natural aging and enhance artificial aging. The mechanism controlling the aging is argued to be vacancy diffusion, with solutes trapping vacancies a ...

American Physical Society2014

Atomistic Modeling of Effect of Mg on Oxygen Vacancy Diffusion in alpha-Alumina

Paul Bowen, Ulrich Aschauer, Abhishek Tewari

Oxygen diffusion plays an important role in grain growth and densification during the sintering of alumina ceramics and governs high-temperature processes such as creep. The atomistic mechanism for oxygen diffusion in alumina is, however, still debated; at ...

Wiley-Blackwell2014

Quasi-elastic neutron scattering in the multi-GPa range and its application to liquid water

Livia Eleonora Bove Kado

We present a method which allows quasi-elastic neutron scattering (QENS) at multi-GPa pressures, i.e., pressure conditions which are an order of magnitude higher than possible with QENS till now. The technique uses an opposed-anvil geometry with a sample c ...

Amer Inst Physics2013

Defect ordering and defect-domain-wall interactions in PbTiO3: A first-principles study

Nava Setter, Nicola Marzari, Dragan Damjanovic, Anand Chandrasekaran

The properties of ferroelectric materials, such as lead zirconate titanate (PZT), are heavily influenced by the interaction of defects with domain walls. These defects are either intrinsic or are induced by the addition of dopants. We study here PbTiO3 (th ...

Amer Physical Soc2013

Molecular Dynamics Simulations of Helium Atoms Clustering in bcc Iron

Ning Gao

Helium atoms are known to have a significant impact on materials used in fission and fusion reactors. In particular, the presence of helium atoms can change the mechanical properties and degrade the lifetime of reactors. In order to develop the helium-resi ...

EPFL2011

High temperature mechanical spectroscopy of yttria stabilized zirconia reinforced with carbon nanotubes

Daniele Mari, Robert Schaller, Mehdi Mazaheri

High temperature mechanical properties of zirconia reinforced with carbon-nanotubes (CNTs) are studied by mechanical spectroscopy. CNTs limit zirconia grain-boundary sliding (GBS) and consequently deformation. Concurrent grain-growth and plastic deformatio ...

Wiley2010

Atomistic simulations of nanometric dislocation loops in bcc tungsten

Robin Schäublin

Small dislocation loops formed from self-interstitial atoms (SIAs) are commonly found in irradiated metals. These defects signiﬁcantly inﬂuence the mechanical properties of the materials. Atomistic simulations are used to describe nanometric circular dislo ...

Elsevier2009

Cellular Toxicity of TiO2-Based Nanofilaments

László Forró, Arnaud Magrez, Rita Smajda, Lenke Horváth, Beat Schwaller

At present, nanofilaments are not exclusively based on carbon atoms but can be produced from many inorganic materials in the form of nanotubes and nanowires. It is essential to systematically assess the acute toxicity of these newly synthesized materials s ...

2009

Stability of helium bubbles in alpha-iron: A molecular dynamics study

Robin Schäublin, Guillaume Lucas

Molecular dynamics simulations were performed to estimate the dissociation energies of helium interstitials, vacancies and self-interstitial atoms from small helium-vacancy clusters. Several sets of empirical potentials have been tested and compared with a ...

Elsevier2009

Measurement of Slow Diffusion Coefficients of Molecules with Arbitrary Scalar Couplings via Long-Lived Spin States

Geoffrey Bodenhausen, Paul Romeo Vasos, Riddhiman Sarkar, Puneet Ahuja

New experiments are described for the determination of very slow diffusion constants by nuclear magnetic resonance (NMR) using long-lived (singlet) states. These experiments are suitable for molecules or conformations featuring a wide range of J-couplings. ...

2008

Direct Measurement of Effective Diffusion Coefficients in Nanochannels Using Steady-State Dispersion Effects

Philippe Renaud, Arnaud Bertsch, Nicolas Durand, Mina Todorova

We present a method to measure effective diffusion coefficients of fluorescently labeled molecules inside a nanofluidic system. Molecules with small diffusion coefficients show a larger lateral dispersion than highly diffusive species, which is counterintu ...

American Institute of Physics2007

Multiscale modeling of crowdion and vacancy defects in body-centered-cubic transition metals

We investigate the structure and mobility of single self-interstitial atom and vacancy defects in body-centered-cubic transition metals forming groups 5B (vanadium, niobium, and tantalum) and 6B (chromium, molybdenum, and tungsten) of the Periodic Table. D ...

2007

A sensitive in vivo model for quantifying interstitial convective transport of injected macromolecules and nanoparticles

Melody Swartz, Sai Reddy

Effective interstitial transport of particles is necessary for injected drug/diagnostic agents to reach the intended target; however, quantitative methods to estimate such transport parameters are lacking. In this study we develop an in vivo model for eval ...

2006

Linking drainage front morphology with gaseous diffusion in unsaturated porous media: A lattice Boltzmann study

Dani Or

The effect of drainage front morphology on gaseous diffusion through partially saturated porous media is analyzed using the lattice Boltzmann method (LBM). Flow regimes for immiscible displacement in porous media have been characterized as stable displacem ...

2006

Impact of Liquid Configuration and Flow Regimes on Macroscopic Transport Properties in Unsaturated Porous Media: A Lattice Boltzmann Study

Dani Or

The effect of flow regime and fluid morphology (distribution and spatial arrangement) on macroscopic transport properties (effective diffusion coefficient, hydraulic conductivity) was analyzed using a multi-component lattice Boltzmann model. Various flow r ...

2005

INFLUENCE OF POROSITY AND WATER CONTENT ON THE DIFFUSIVITY OF CO2 AND O2 THROUGH HYDRATED CEMENT PASTE

Yves Houst

Knowledge of the diffusivity of CO2 and 02 is of considerable importance for a quantitative assessment of the carbonation and corrosion of the reinforcement in concrete. A special measuring cell which allows the simultaneous determination of the effective ...

Pergamon-Elsevier Science Ltd1994