High-sensitivity visualization of localized electric fields using low-energy electron beam deflection
High-sensitivity visualization of localized electric fields using low-energy electron beam deflection
复制标题
DOI：
10.7567/jjap.57.065201
复制
发表时间：
2018-05
影响因子：
1.5
通讯作者：
Samuel Jeong;Yoshikazu Ito;Gary Edwards;J. Fujita
中科院分区：
文献类型：
--
作者：
Samuel Jeong;Yoshikazu Ito;Gary Edwards;J. Fujita
纳米催化剂上局部电子电荷的可视化有望获得催化反应机制的基本信息。我们开发了一种高灵敏度的检测技术，用于可视化催化剂上的局部电荷及其相应的电场分布，使用1至5 keV的低能电子束和高灵敏度的扫描透射电子显微镜（STEM）探测器。在距离一次电子能量为1 keV的局域电荷约17µm处，观察局域电场的最高灵敏度为~ 0.08 V/µm，并且可以观察到积聚在碳纳米管（CNT）顶端的200个电子产生的弱局域电场。我们还观察到，分布在碳纳米管林中的金纳米粒子倾向于在−2 V偏压下积累一定数量的电荷，约150个电子。
The visualization of localized electronic charges on nanocatalysts is expected to yield fundamental information about catalytic reaction mechanisms. We have developed a high-sensitivity detection technique for the visualization of localized charges on a catalyst and their corresponding electric field distribution, using a low-energy beam of 1 to 5 keV electrons and a high-sensitivity scanning transmission electron microscope (STEM) detector. The highest sensitivity for visualizing a localized electric field was ∼0.08 V/µm at a distance of ∼17 µm from a localized charge at 1 keV of the primary electron energy, and a weak local electric field produced by 200 electrons accumulated on the carbon nanotube (CNT) apex can be visualized. We also observed that Au nanoparticles distributed on a CNT forest tended to accumulate a certain amount of charges, about 150 electrons, at a −2 V bias.