Inada Hiromi, Wu Lijun, Wall Joe, Su Dong, Zhu Yimei
Brookhaven National Laboratory, Upton, NY 11973, USA.
J Electron Microsc (Tokyo). 2009 Jun;58(3):111-22. doi: 10.1093/jmicro/dfp011. Epub 2009 Mar 1.
We report the performance of the first aberration-corrected scanning transmission electron microscope (STEM) manufactured by Hitachi. We describe its unique features and versatile capabilities in atomic-scale characterization and its applications in materials research. We also discuss contrast variation of the STEM images obtained from different annular dark-field (ADF) detectors of the instrument, and the increased complexity in contrast interpretation and quantification due to the increased convergent angles of the electron probe associated with the aberration corrector. We demonstrate that the intensity of atomic columns in an ADF image depends strongly on a variety of imaging parameters, sample thickness, as well as the nuclear charge and the deviation from their periodic position of the atoms we are probing. Image simulations are often required to correctly interpret the atomic structure of an ADF-STEM image.
我们报告了日立公司制造的首台像差校正扫描透射电子显微镜（STEM）的性能。我们描述了其在原子尺度表征方面的独特特征和多样功能，以及它在材料研究中的应用。我们还讨论了从该仪器不同环形暗场（ADF）探测器获得的STEM图像的对比度变化，以及由于与像差校正器相关的电子探针会聚角增加而导致的对比度解释和量化方面增加的复杂性。我们证明，ADF图像中原子列的强度强烈依赖于各种成像参数、样品厚度，以及我们所探测原子的核电荷和它们偏离周期性位置的程度。通常需要进行图像模拟才能正确解释ADF-STEM图像的原子结构。
