合金纳米粒子生长形态的分子动力学模拟

The growth configuration of nanoalloy: a molecular dynamics simulation

选用Cu–Ag纳米粒子作为研究对象,采用分子动力学方法和嵌入原子模型模拟了将Cu原子注入到由Ag原子构成的纳米粒子的过程,研究了注入能量(10,30,50 e V)与纳米粒子结构的关系。采用共近邻分析技术对合金纳米的结构演变进行了研究。模拟结果表明:当入射原子动能为50 e V时,合金纳米粒子从截角八面体转变为二十面体结构。这种转变是因为入射原子与基底原子碰撞,促使系统温度升高。

The impact depositions of Cu atoms onto the Ag truncated octahedron are simulated by molecular dynamics along with the embedded atom method. The dependence of incident energies(10, 30 and 50 e V) and the nanoalloy configuration is found. The common neighbor analysis is used to identify the structural evolutions. A structural transformation from truncated octahedral to icosahedral arrangement is observed at incident energy of 50 e V. The structural transformation can be induced by the increase of system temperature, because the incident energy of the deposited atom is delivered to the substrate atoms as a result of collisions.