Monte Carlo simulation of order-disorder transformation in nano particles of Cu3Au alloy
Monte Carlo simulation of order-disorder transformation in nano particles of Cu3Au alloy
复制标题
Cu3Au合金纳米粒子有序-无序转变的蒙特卡罗模拟
DOI：
10.1007/s004600050261
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
Y. Hirotsu
中科院分区：
文献类型：
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作者：
T. Tadaki;T. Kinoshita;Y. Nakata;T. Ohkubo;Y. Hirotsu
利用改进的嵌入原子法(MEAM)计算了Cu3Au合金纳米颗粒的基态能量，并利用MEAM获得的多体势，采用蒙特卡罗方法对其中的有序-无序转变进行了计算机模拟。对直径为 2 nm 和 3 nm、分别含有 321 个和 1061 个原子的纳米粒子和尺寸为 5 × 5 × 5 晶胞的 3 种模型晶体进行了计算，对其施加周期性边界条件。结果发现，纳米颗粒中完美有序态和无序态之间的基态能量差异比块体中的要小，并且临界温度T随着颗粒尺寸的减小而显着降低。根据我们之前的实验，纳米粒子中的原子有序性似乎存在一定的临界尺寸，并且在纳米粒子中T显着降低。这些实验结果似乎可以由目前的计算结果定性地解释。
The ground state energy of nano particles of the Cu3Au alloy is calculated by utilizing the modified embedded atom method(MEAM), and a computer simulation is made of the order-disorder transition therein by Monte Carlo method with the many-body potential obtained by MEAM. The calculations have been made for three kinds of model crystals of nano particles with 2 nm and 3 nm in diameter, containing 321 and 1061 atoms, respectively, and of a bulk with a size of 5 × 5 × 5 unit cells, on which the periodic boundary condition is imposed. As a result, it is found that the difference in ground state energy between perfectly ordered and disordered states becomes less in nano particles than in the bulk, and that the critical temperatureTdecreases markedly with decreasing particle size. According to our previous experiments, there seems to be a certain critical size for the atomic ordering in the nano particles, andTis depressed remarkably in the nano particles. These experimental results appear to be accounted for by the present calculated ones qualitatively.