Center for High-Resolution Electron Microscopy, College of Materials Science and Engineering, Hunan University, Changsha 410082, China.
Ultramicroscopy. 2013 Nov;134:135-43. doi: 10.1016/j.ultramic.2013.04.013. Epub 2013 May 16.
Three different types of multislice algorithms, namely the conventional multislice (CMS) algorithm, the propagator-corrected multislice (PCMS) algorithm and the fully-corrected multislice (FCMS) algorithm, have been evaluated in comparison with respect to the accelerating voltages in transmission electron microscopy. Detailed numerical calculations have been performed to test their validities. The results show that the three algorithms are equivalent for accelerating voltage above 100kV. However, below 100 kV, the CMS algorithm will introduce significant errors, not only for higher-order Laue zone (HOLZ) reflections but also for zero-order Laue zone (ZOLZ) reflections. The differences between the PCMS and FCMS algorithms are negligible and mainly appear in HOLZ reflections. Nonetheless, when the accelerating voltage is further lowered to 20 kV or below, the PCMS algorithm will also yield results deviating from the FCMS results. The present study demonstrates that the propagation of the electron wave from one slice to the next slice is actually cross-correlated with the crystal potential in a complex manner, such that when the accelerating voltage is lowered to 10 kV, the accuracy of the algorithms is dependent of the scattering power of the specimen.
三种不同类型的多层算法，即传统多层（CMS）算法、传播子校正多层（PCMS）算法和完全校正多层（FCMS）算法，已在透射电子显微镜的加速电压方面进行了评估。已经进行了详细的数值计算来测试它们的有效性。结果表明，对于高于 100kV 的加速电压，这三种算法是等效的。然而，在 100kV 以下，CMS 算法将引入显著的误差，不仅对于高阶劳厄区（HOLZ）反射，而且对于零阶劳厄区（ZOLZ）反射。PCMS 和 FCMS 算法之间的差异可以忽略不计，主要出现在 HOLZ 反射中。尽管如此，当加速电压进一步降低到 20kV 或更低时，PCMS 算法也将产生与 FCMS 结果偏离的结果。本研究表明，电子波从一个切片传播到下一个切片实际上与晶体势以复杂的方式相互关联，因此当加速电压降低到 10kV 时，算法的准确性取决于试样的散射功率。
