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Calculation of thermodynamic properties of Ni nanoclusters via selected equations of state based on molecular dynamics simulations

Akbarzadeh, H ; Sharif University of Technology | 2011

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  1. Type of Document: Article
  2. DOI: 10.1016/j.ssc.2011.05.011
  3. Publisher: 2011
  4. Abstract:
  5. We present an approach for constant-pressure molecular dynamics simulations. This approach is especially designed for finite systems, for which no periodic boundary condition applies. A molecular dynamics (MD) simulation for Ni nanoclusters is used to calculate their pressurevolumetemperature (pvT) data for the temperature range 200 K≤T≤400 K, and pressures up to 600 kbar. Isothermal sets of pvT data were generated by the simulation; each set was fitted by three equations of state (EoSs): Linear Isotherm Regularity-II (LIRII), BirchMurnaghan (BM), and EOS III. It is found that the MD data are satisfactorily reproduced by the EoSs with reasonable precision. Some features of the EoSs criteria, such as the temperature dependences of the coefficients, the isothermal bulk modulus and its pressure derivative at the zero-pressure limit, and isobaric thermal expansion for Ni nanoclusters, are investigated. We have found that same EoSs are valid for both bulk Ni and Ni nanoclusters, but with different values of the parameters, which depend on the cluster size and temperature. An increase in bulk modulus with decrease of cluster size can be observed. Also, an increase in isobaric expansion coefficient with decrease of cluster size has been found
  6. Keywords:
  7. A. Nickel nanocluster ; C. Bulk modulus ; C. Equation of state ; B. Molecular dynamics ; Cluster sizes ; Equation of state ; Finite systems ; Isobaric expansion coefficients ; Isothermal bulk modulus ; Linear isotherms ; Molecular dynamics simulations ; Nickel-nanoclusters ; Periodic boundary conditions ; Pressure derivatives ; PVT data ; Temperature dependence ; Temperature range ; Cluster analysis ; Dynamics ; Elastic moduli ; Equations of state ; Nanoclusters ; Temperature ; Thermal expansion ; Molecular dynamics
  8. Source: Solid State Communications ; Volume 151, Issue 14-15 , 2011 , Pages 965-970 ; 00381098 (ISSN)
  9. URL: http://www.sciencedirect.com/science/article/pii/S0038109811002456