Sandia National Laboratories, Carlsbad, NM, USA.
J Phys Condens Matter. 2010 Jun 9;22(22):225405. doi: 10.1088/0953-8984/22/22/225405. Epub 2010 May 20.
We have performed molecular dynamics simulations of cascade damage in the gadolinium pyrochlore Gd₂Zr₂O₇, comparing results obtained from traditional simulation methodologies that ignore the effect of electron-ion interactions with a 'two-temperature model' in which the electronic subsystem is modeled using a diffusion equation to determine the electronic temperature. We find that the electron-ion interaction friction coefficient γ(p) is a significant parameter in determining the behavior of the system following the formation of the primary knock-on atom (PKA; here, a U³(+) ion). The mean final PKA displacement and the number of defect atoms formed is shown to decrease uniformly with increasing γ(p); however, other properties, such as the final equilibrium temperature and the oxygen-oxygen radial distribution function, show a more complicated dependence on γ(p).
我们对钆烧绿石 Gd₂Zr₂O₇中的级联损伤进行了分子动力学模拟，比较了忽略电子-离子相互作用影响的传统模拟方法和“双温模型”的结果，其中电子子系统采用扩散方程建模以确定电子温度。我们发现，电子-离子相互作用摩擦系数 γ(p) 是决定系统在形成初级碰撞原子（PKA；这里是 U³(+) 离子）后的行为的重要参数。平均最终 PKA 位移和形成的缺陷原子数量与 γ(p) 呈均匀减小的趋势；然而，其他性质，如最终平衡温度和氧-氧径向分布函数，对 γ(p) 的依赖关系更为复杂。
