论文标题
研究长波弯曲振动对通过分子动力学方法破坏超薄膜破坏的贡献
Study of the contribution of long-wave bending vibrations to the destruction of ultrathin films by the method of molecular dynamics
论文作者
论文摘要
分子动力学方法用于研究薄膜动态不稳定性的发展过程，从而导致其破坏。对薄（5个原子层）$ FCC $铝膜进行计算，该计算是使用原子间相互作用势测试的，该计算通过将数值结果与弹性理论框架中获得的分析结果进行比较。为此，开发了一种原始方法，该方法允许使用分子动力学方法计算超薄膜中长波声子的分散定律。该系统在$ 0.6 ns $的时间间隔内保持稳定的温度（$ <600 k $）。这使得分析频谱的低频部分至最小频率$ν_{min} = 0.0166 thz $（$ t = 50 k $），并确定最长的振动频率，对于最长的几何，对于此问题几何，弯曲wave $ν_{0} = 0.033 thz $ calling depersive call verne shece call verneps call vernessive降低了温度的温度。一旦该模式的振动周期与模拟时间相媲美，在计算过程中会发生这种模式的幅度的持续增加，该幅度将称为“延迟模式”。结果表明，薄膜破坏始于达到弯曲波幅度的某个临界值。
The molecular dynamics method is used to study the process of development of dynamic instability of a thin film, leading to its destruction. The calculations are performed for a thin (5 atomic layers) $fcc$ aluminum film using the interatomic interaction potential tested by comparing the numerical results with the analytical ones obtained in the framework of elasticity theory. For this purpose, an original approach is developed, which allows one to calculate the dispersion law of long-wave phonons in ultrathin films using the molecular dynamics method. The temperatures ($< 600 K$) at which the system remains stable over a time interval of $0.6 ns$ are found. This makes it possible to analyze the low-frequency part of the spectrum down to the minimum frequency $ν_{min}=0.0166 THz$ (at $T = 50 K$), and to determine the vibration frequency of the longest, for this problem geometry, bending wave $ν_{0}=0.033 THz$ which decreases with increasing temperature, hence, its period grows. Once the vibration period of this mode becomes comparable with the time of simulation, there occurs, during calculation, a continuous increase in the amplitude of this mode which will be referred to as "retarded mode". It is shown that the film destruction begins with the attainment of a certain critical value of the bending wave amplitude.
