Open AccessThermal dynamics properties of bcc Mo nanofilm from MD simulation
Author(s) -
Ming Jia,
Lai Yan-Qing,
ZhongQun Tian,
Yexiang Liu
Publication year - 2009
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.58.1139
Subject(s) - materials science , gibbs free energy , heat capacity , molecular dynamics , atom (system on chip) , molybdenum , surface energy , thermodynamics , thermal , volume (thermodynamics) , melting temperature , composite material , physics , chemistry , metallurgy , computational chemistry , computer science , embedded system
Using molecular dynamics simulation with the modified analytic embedded-atom method (MAEAM), we calculated Gibbs free energy and surface free energy of bcc Mo with high melting temperature Tf, and further obtained the Gibbs free energy of its nanofilms. Based on the Gibbs free energy of nanofilms, we investigated the heat capacity of molybdenum nanofilms at constant pressure or at constant volume. The analysis reveals that the molar heat capacity of bulk sample is lower than that of the nanofilms, and the difference increases with the decrease of the film thickness. It is also observed that such size effect of Mo nanofilm is not really significant until the thickness is less than about 15—20nm. It is the surface atoms that determine the size effect on the thermodynamic properties of nanofilms. The difference between CV and CP of nanofilms is firstly analysed quantitatively and the calculated result for CV/CP varies linearly with T/Tf and relates directly to film thickness.