Melting of Argon Cluster: Dependence of Caloric Curves on MD Simulation Parameters

作     者：Mohamed Tabti Adil Eddahbi Said Ouaskit Lahcen Elarroum 

作者机构：Laboratoire de la Physique de la Matière Condensée (LPMC) Mohammedia Faculté des Sciences Ben M’Sik Université Hassan II Casablanca Morocco 

出 版 物：《World Journal of Condensed Matter Physics》 (凝固态物理国际期刊（英文）)

年 卷 期：2012年第2卷第3期

页      面：139-147页

学科分类：1002[医学-临床医学] 100214[医学-肿瘤学] 10[医学] 

主　　题：Molecular Dynamics Calculations Clusters Entropy Fluctuation Internal Interaction Self-Organization Phase Transformations Transition Nanostructures Melting Argon 

摘      要：We report on molecular dynamics simulations performed using microcanonical ensemble to predict the melting of argon particles in nanometer size range 10 nm and to investigate the effect of the time step integration. We use the Lennard- Jones potential functions to describe the interatomic interactions, and the results are evaluated by using caloric curves of the melting phenomenon. Thermodynamic properties, including the total energy, Lindemann parameter, kinetic and potential distribution’s functions, are used to characterize the melting process. The data shows bimodal behavior only in a certain interval of integration time step Δt, while the internal energy increases monotonically with the temperature. For the other time step values, the back bending disappears. We claim that negative specific heat is related to a possible decrease of entropy in an isolated system;this can be interpreted as a result of the internal interactions, especially attractive process and specific relaxation time.