Zeiger Paul M, Rusz Ján
Department of Physics and Astronomy, Uppsala University, P.O. Box 516, Uppsala 75120, Sweden.
Phys Rev Lett. 2020 Jan 17;124(2):025501. doi: 10.1103/PhysRevLett.124.025501.
We introduce a novel method for the simulation of the impact scattering in vibrational scanning transmission electron microscopy electron energy loss spectroscopy simulations. The phonon-loss process is modeled by a combination of molecular dynamics and elastic multislice calculations within a modified frozen phonon approximation. The key idea is thereby to use a so-called δ thermostat in the classical molecular dynamics simulation to generate frequency dependent configurations of the vibrating specimen's atomic structure. The method includes correlated motion of atoms and provides vibrational spectrum images at a cost comparable to standard frozen phonon calculations. We demonstrate good agreement of our method with simulations and experiments for a 15 nm flake of hexagonal boron nitride.
我们介绍了一种用于振动扫描透射电子显微镜电子能量损失谱模拟中冲击散射模拟的新方法。声子损失过程通过分子动力学和弹性多切片计算相结合，并在改进的冻结声子近似下进行建模。其关键思想是在经典分子动力学模拟中使用所谓的δ恒温器来生成振动样品原子结构的频率相关构型。该方法包括原子的相关运动，并以与标准冻结声子计算相当的成本提供振动光谱图像。我们证明了我们的方法与六方氮化硼15纳米薄片的模拟和实验结果具有良好的一致性。
