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Titre du document / Document title

Analysis of semi-empirical interatomic potentials appropriate for simulation of crystalline and liquid Al and Cu

Auteur(s) / Author(s)

MENDELEV M. I. (1) ; KRAMER M. J. (1) ; BECKER C. A. (2) ; ASTA M. (3) ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

(1) Materials and Engineering Physics, Ames Laboratory, Ames, IA 50011, ETATS-UNIS
(2) Metallurgy Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, ETATS-UNIS
(3) Department of Chemical Engineering and Materials Science, University of California, Davis, CA 95616, ETATS-UNIS

Résumé / Abstract

We investigate the application of embedded atom method (EAM) interatomic potentials in the study of crystallization kinetics from deeply undercooled melts, focusing on the fcc metals Al and Cu. For this application, it is important that the EAM potential accurately reproduces melting properties and liquid structure, in addition to the crystalline properties most commonly fit in its development. To test the accuracy of previously published EAM potentials and to guide the development of new potential in this work, first-principles calculations have been performed and new experimental measurements of the Al and Cu liquid structure factors have been undertaken by X-ray diffraction. We demonstrate that the previously published EAM potentials predict a liquid structure that is too strongly ordered relative to measured diffraction data. We develop new EAM potentials for Al and Cu to improve the agreement with the first-principles and measured liquid diffraction data. Furthermore, we calculate liquid-phase diffusivities and find that this quantity correlates well with the liquid structure. Finally, we perform molecular dynamics simulations of crystal nucleation from the melt during quenching at constant cooling rate. We find that EAM potentials, which predict the same zero-temperature crystal properties but different liquid structures, can lead to quite different crystallization kinetics. More interestingly, we find that two potentials predicting very similar equilibrium solid and liquid properties can still produce very different crystallization kinetics under far-from-equilibrium conditions characteristic of the rapid quenching simulations employed here.

Revue / Journal Title

Philosophical magazine    ISSN  1478-6435 

Source / Source

2008, vol. 88, no12, pp. 1723-1750 [28 page(s) (article)] (70 ref.)

Langue / Language

Anglais

Editeur / Publisher

Taylor & Francis, Abingdon, ROYAUME-UNI  (2003) (Revue)

Mots-clés anglais / English Keywords

Liquid solid equilibrium

;

Crystal structure

;

Temperature effects

;

Solidification

;

Cooling rate

;

Rate constant

;

Liquid state quenching

;

Crystal nucleation

;

Molecular dynamics method

;

Theoretical study

;

Diffusivity

;

Liquid state

;

FCC lattices

;

Copper

;

Liquid crystals

;

Diffusion

;

XRD

;

Structure factors

;

Density functional method

;

Liquid structure

;

Melting

;

Focusing

;

Supercooling

;

Kinetics

;

Crystallization

;

Embedded atom method

;

Digital simulation

;

Interatomic potential

;

Semiempirical method

;

Mots-clés français / French Keywords

6470K

;

8130F

;

Equilibre liquide solide

;

Structure cristalline

;

Effet température

;

Solidification

;

Vitesse refroidissement

;

Constante vitesse

;

Trempe état liquide

;

Germination cristalline

;

Méthode dynamique moléculaire

;

Etude théorique

;

Diffusivité

;

Etat liquide

;

Réseau cubique face centrée

;

Cuivre

;

Cristal liquide

;

Diffusion(transport)

;

Diffraction RX

;

Facteur structure

;

Méthode fonctionnelle densité

;

Structure état liquide

;

Fusion

;

Focalisation

;

Surfusion

;

Cinétique

;

Cristallisation

;

Méthode atome enrobé

;

Simulation numérique

;

Potentiel interatomique

;

Méthode semiempirique

;

Mots-clés espagnols / Spanish Keywords

Equilibrio líquido sólido

;

Constante velocidad

;

Temple estado líquido

;

Germinación cristalina

;

Estado líquido

;

Método átomo revestido

;

Potencial interatómico

;

Método semiempírico

;

Localisation / Location

INIST-CNRS, Cote INIST : 134 A3, 35400018583550.0010

Nº notice refdoc (ud4) : 20696120



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