Size Effects on Cohesive Energy, Debye Temperature and Lattice Heat Capacity from First-Principles Calculations of Sn Nanoparticles

The size-dependent cohesive energy, melting temperature, Debye temperature and lattice heat capacity are investigated using density functional theory within generalized gradient approximation of Sn nanoparticles. The analyses of the obtained total energies are presented by considering effect of mean bond length and the ratio number of surface atoms to that of its internal with size. The cohesive energy is calculated for Sn nanoparticles and the obtained data are used to determine melting temperature, Debye temperature and lattice heat capacity. The cohesive energy, melting point and Debye temperature drop while the lattice specific heat rise when the size is decreased due to the effects of the elevated bond length stretch. The results obtained are in excellent agreement with the available experimental results for melting point and Debye temperature of Sn nanoparticles. Also, the same trend variations of the lattice heat capacity obtained for Sn nanoparticles to that calculated theoretically in Se and Cu.