期刊
ULTRAMICROSCOPY
卷 108, 期 2, 页码 126-140出版社
ELSEVIER
DOI: 10.1016/j.ultramic.2007.03.008
关键词
zernike phase plate; boersch lens; radiation damage; transmission electron microscope; spherical aberration; high-resolution TEM; biological TEM; single molecule TEM; low-voltage TEM
类别
We have optimized a bright-field transmission electron microscope for imaging of high-resolution radiation-sensitive materials by calculating the imaging dose no needed to obtain a signal-to-noise ratio (SNR) = 5. Installing a Zernike phase plate (ZP) decreases the dose needed to detect single atoms by as much as a factor of two at 300 kV. For imaging larger objects, such as Gaussian objects with full-width at half-maximum larger than 0.15nm, ZP appears more efficient in reducing the imaging dose than correcting for spherical aberration. The imaging dose no does not decrease with extending of chromatic resolution limit by reducing chromatic aberration, using high accelerating potential (U-0 = 300 kV), because the image contrast increases slower than the reciprocal of detection radius. However, reducing chromatic aberration would allow accelerating potential to be reduced leading to imaging doses below 10e(-)/angstrom(2) for a single iodine atom when a CS-corrector and a ZP are used together. Our simulations indicate that, in addition to microscope hardware, optimization is heavily dependent on the nature of the specimen under investigation. (c) 2007 Elsevier B.V. All rights reserved.
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