Simulations were used to investigate the surface energy and self-diffusion coefficient in aluminum nanoclusters (AlN) as a function of temperature, T (T = 300-1100K), and size (N = 108-4000 atoms, with N the number of atoms in the cluster), with the self-diffusion coefficient compared with the bulk limit. Debye temperature, cohesive energy, and average coordination number of AlN were also explored as a function of the cluster size. The surface energy decreased as a function of size as well as temperature, and became very small at sizes larger than N ≥ 2000, while the average coordination number and the Debye temperature increased as a function of nanocluster size. The self-diffusion coefficient decreased with increasing size as N−2/3, while increasing as a function of temperature, and exhibited values substantially larger than in the bulk, quantitatively confirming the much greater structural freedom encountered of nanoscale systems.

Dependence of Self-Diffusion Coefficient, Surface Energy, on Size, Temperature, and Debye Temperature on Size for Aluminum Nanoclusters. Taherkhani, F., Akbarzadeh, H., Abroshan, H., Fortunelli, A.: Fluid Phase Equilibria, 2012, 335, 26-31