期刊
NEW JOURNAL OF PHYSICS
卷 15, 期 -, 页码 -出版社
IOP PUBLISHING LTD
DOI: 10.1088/1367-2630/15/4/043015
关键词
-
资金
- National Science Council, Republic of China [NSC95-2112-M-001-009]
- Academia Sinica, Republic of China [AS-99-TP-A02]
There has been controversy about the interpretation of the interference patterns recorded with low-energy electron point projection microscopy. With a highly coherent single-atom electron source, we have used a point projection microscope (PPM) to image a suspended and isolated single-walled carbon nanotube at different tip-sample separations. The nanotube and the surrounding structure are also imaged with a transmission electron microscope. Through numerical simulations, we can fit well the interference patterns of the nanotube recorded by the PPM at different separations. Our simulation results indicate that the interference patterns can be considered as electron holograms at large tip-sample separations (or small magnifications). However, at small tip-sample separations, the interference patterns are dominated by the biprism effect due to significant charge density induced on the nanotube, and thus, the interference patterns contain little information about the internal structure of the object. The results provide a reason why the images obtained by point projection microscopy so far have never achieved a resolution smaller than 2 nm. New research directions for achieving high-resolution imaging of biological molecules with low-energy electrons are also discussed.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据