ORDER-DISORDER TRANSITION PRODUCED BY DISLOCATIONS IN AN FCC LENNARD-JONES SOLID
Résumé
A pseudostatic computational model has been used to study the structural and thermodynamic changes associated with an imposed order-disorder transition. Atomic displacement operations corresponding to the insertion of randomly situated and oriented perfect dislocations were repeatedly performed until saturation was observed. Each dislocation was generated according to the elastic solution for the displacement field and subsequently the system was permitted to relax using a modified molecular dynamics technique. The resulting disordered atomic configuration was found to display a liquid-like structure. In a fully dynamical simulation of the melting process the formation of small partial dislocation loops of the Shockly type was observed. The concentration of dislocations was found to increase as the melting process progressed. Both the pseudostatic and the fully dynamical simulation thus exhibit features which support the dislocation theory of melting.
Domaines
Articles anciensOrigine | Accord explicite pour ce dépôt |
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