An inelastic multislice simulation method incorporating plasmon energy losses
An inelastic multislice simulation method incorporating plasmon energy losses
复制标题
包含等离子体能量损失的非弹性多层模拟方法
DOI：
10.1016/j.ultramic.2019.112816
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发表时间：
2019-11-01
期刊：
影响因子：
2.2
通讯作者：
Mendis, B. G.
中科院分区：
文献类型：
--
作者：
Mendis, B. G.
定量电子显微镜需要精确的模拟方法，考虑样品内高能电子的弹性和非弹性散射。这里提出了一种将等离激元激发（固体中主要的能量损失机制）与传统的冻结声子、多层模拟相结合的方法。基于蒙特卡罗的方法使用随机数估计等离子体散射路径长度和散射角，并相应地修改多切片计算中的传输和传播函数。 [110]-Si 中的能量过滤、会聚束电子衍射图案的比较表明模拟与实验之间具有良好的一致性。模拟还表明，由于等离子体激元散射角抑制电子束沿原子柱的沟道，等离子体激元激发降低了来自原子柱的高角度环形暗场信号。然而，对原子柱的分辨率和峰背景比的影响很小。
Quantitative electron microscopy requires accurate simulation methods that take into account both elastic and inelastic scattering of the high energy electrons within the specimen. Here a method to combine plasmon excitations, the dominant energy loss mechanism in a solid, with conventional frozen phonon, multislice simulations is presented. The Monte Carlo based method estimates the plasmon scattering path length and scattering angle using random numbers and modifies the transmission and propagator functions in the multislice calculation accordingly. Comparison of energy filtered, convergent beam electron diffraction patterns in [110]-Si show good agreement between simulation and experiment. Simulations also show that plasmon excitation decreases the high angle annular dark field signal from atom columns, due to the plasmon scattering angle suppressing electron beam channeling along the atom columns. The effect on resolution and peak-to-background ratio of the atom columns is however small.