Key factors for the dynamic ETEM observation of single atoms.
Key factors for the dynamic ETEM observation of single atoms.
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DOI：
10.1093/jmicro/dft033
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发表时间：
2013-12
期刊：
影响因子：
1.8
通讯作者：
Kenta Yoshida;T. Tominaga;T. Hanatani;A. Tagami;Y. Sasaki;J. Yamasaki;K. Saitoh;Nobuo Tanaka
中科院分区：
文献类型：
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作者：
Kenta Yoshida;T. Tominaga;T. Hanatani;A. Tagami;Y. Sasaki;J. Yamasaki;K. Saitoh;Nobuo Tanaka
我们对像差校正的环境透射电子显微镜(AC-ETEM)提出了进一步的改进，以用于单原子的动态HRTEM观察。额外的泵浦水平包括三个额外的涡轮分子泵(TMP)，使样品室中的基本压力达到3.5×10(-5)Pa.这些额外的TMP对图像分辨率的影响是在倒易空间中用标准交叉光栅样品上的信息极限(杨氏条纹)和非晶态碳膜(铂/a-碳)上的铂(铂)单原子测量的。用铂/a-碳测量了气体压力对单原子成像的影响，并评价了TMP、样品、磁透镜和AC-Etem显微镜柱子的振动。当使用防振工作台时，TMPS不影响ETEM成像性能，分辨率达到0.10 nm。利用改进的AC-ETEM系统和时间分辨率为0.05 S的高速摄像机，在4.0×10~(-2)帕的空气中实现了对铂单原子的动态电子能谱观测。
We present further modifications to aberration-corrected environmental transmission electron microscopy (AC-ETEM) for the dynamic HRTEM observation of single atoms. Additional pumping levels that include three additional turbomolecular pumps (TMPs) enable a base pressure of 3.5 × 10(-5) Pa in the sample chamber. The effect of these additional TMPs on image resolution was measured in reciprocal space using information limit (Young's fringes) on a standard cross grating sample and also with platinum (Pt) single atoms on an amorphous carbon film (Pt/a-carbon). The Pt/a-carbon was used for measuring the effect of gas pressure on single-atom imaging in addition to the evaluation of vibrations of TMPs, samples, magnetic lenses and a microscope column of the AC-ETEM. TMPs did not affect the ETEM imaging performance when an anti-vibration table was used, and 0.10-nm resolution was achieved. Dynamic ETEM observation of Pt single atoms was achieved in 4.0 × 10(-2) Pa of air, using a modified AC-ETEM system and a high-speed CCD camera with a time resolution of 0.05 s.