Molecular Dynamics Study On Melting Of Pd Cluster

Microscopic matter problem attracts researchers'attention more and more because it has different rules from macroscopic one. Therefore, it needs to be studied detailed to build corresponding theories. In the microscopic matter, nanomatter is typical and even many people call it the most hopeful matter in the future. The property of nanoclusters whose sizes are between molecules and crystals is the transition from the microscopic to the macroscopic with the quantitative growth of particles. Studying the change of structures and properties of them upon melting is important to understand the process of the structural development and to make nanomatterial. At present, it is difficult to study it through experiments because experiments can not measure insular clusters, but the Molecular Dynamics Simulation becomes the ideal tool to research it.In this article, we detailed introduce Molecular Dynamics Simulation, including potential energy functions, equations of integration and so on. The melting process of Pdn (n=13,14,54,55) nanoclusters have been investigated by means of canonical Molecular Dynamics Simulation technique. The curve of the energies and the heat capacity varying with temperature are obtained. It is found that all clusters have pre-melting phenomenon. The melting temperature of cluster does not simply increase with increasing the number of atoms in cluster. The magic number geometries of Pdn clusters (n=13, 55) have narrow pre-melting temperature intervals. Pdn clusters (n=13, 54, 55) have solid-liquid coexistence and Pdn cluster (n=14) shows a surface melting phenomenon.