Melting and crystallization in Ni nanoclusters: The mesoscale regime
Yue Qi, Tahir Çağın, William L. Johnson, William A. Goddard III
Abstract
We studied melting and freezing of Ni nanoclusters with up to 8007 atoms (5.7 nm) using molecular dynamics with the quantum-Sutten–Chen many-body force field. We find a transition from cluster or molecular behavior below ~500 atoms to a mesoscale nanocrystal regime (well-defined bulk and surface properties) above ~750 atoms (2.7 nm). We find that the mesoscale nanocrystals melt via surface processes, leading to Tm,N = Tm,bulk–alphaN^–1/3, dropping from Tm,bulk = 1760 K to Tm,336 = 980 K. Cooling from the melt leads first to supercooled clusters with icosahedral local structure. For N>400 the supercooled clusters transform to FCC grains, but smaller values of N lead to a glassy structure with substantial icosahedral character.
Group Members
Qi, Y., Çağın, T., Johnson, W. L., & III, W. A. G. (2001). Melting and crystallization in Ni nanoclusters: The mesoscale regime. *J. Chem. Phys.*, *115*(1), 385-394. https://doi.org/10.1063/1.1373664