论文标题
用Zernike相板的像差校正的透射电子显微镜
Aberration-corrected transmission electron microscopy with Zernike phase plates
论文作者
论文摘要
我们探讨了将物理相板（PPS）与异常校正的透射电子显微镜结合使用的可能性。计算了相对比的转移特性，并比较了基于薄膜的Zernike PP，无孔（HF）或Volta PP和静电Zach PP的相对性转移特性，并考虑了它们的相位变为相变特性与部分空间相干性。讨论了经常用于高分辨率应用中使用PPS成像的略微融合照明条件的影响。未经加热的Zernike PP的实验应用于各种纳米材料标本，定性分析清楚地证明了PPS和异常校正的透射电子显微镜的一般兼容性。计算和实验显示了该方法的好处，其中包括强大的相对比对比度增强了各种空间频率。这允许在纳米尺度上同时对原子分辨率结构和形态特征进行成像，并具有最大的相对比度。计算可以解释为什么HFPP潮湿的对比度转移在较高的空间频率下。
We explore the possibility of applying physical phase plates (PPs) in combination with aberration-corrected transmission electron microscopy. Phase-contrast transfer characteristics are calculated and compared for a thin-film based Zernike PP, a hole-free (HF) or Volta PP and an electrostatic Zach PP, considering their phase-shifting properties in combination with partial spatial coherence. The effect of slightly converging illumination conditions, often used in high-resolution applications, on imaging with PPs is discussed. Experiments with an unheated Zernike PP applied to various nanomaterial specimens and a qualitative analysis clearly demonstrates the general compatibility of PPs and aberration-corrected transmission electron microscopy. Calculations and experiments show the benefits of the approach, among which is a strong phase-contrast enhancement of a large range of spatial frequencies. This allows the simultaneous imaging of atomic-resolution structures and morphological features at the nanometer scale, with maximum phase contrast. The calculations can explain why the HFPP damps contrast transfer at higher spatial frequencies.
