权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Scanning transmission electron microscopy at low electron energies: basic principles, modelling and quantification

低电子能量下的扫描透射电子显微镜：基本原理、建模和量化

基本信息

批准号：
146004699
负责人：
Professorin Dr. Dagmar Gerthsen
金额：
--
依托单位：
Laboratorium für Elektronenmikroskopie (LEM)
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2009
资助国家：
德国
起止时间：
2008-12-31 至 2019-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/146004699?language=en
关键词：
Scanning transmission electron microscopy low

项目摘要

General goals of the 2nd project phase are, as in the 1st project phase, basic studies regarding contrast formation in scanning transmission electron microscopy (STEM) at electron energies below 30 keV. These energies are typical for scanning electron microscopes which can be fitted by a solid-state STEM detector for the study of electron transparent samples. The resolution is slightly better than 1 nm which is sufficient for solving numerous questions in life science, materials science and nanotechnology. Low-energy STEM can make elaborate (S)TEM studies at high electron energies obsolete which makes low-energy STEM a cost-efficient alternative. Another advantage of the low electron energies is negligible knock-on damage. Specific goals of the 2nd project phase will be a) the study of axial transmission diffraction patterns, b) beam broadening in the sample due to multiple/plural scattering as limiting factor for the resolution in low-energy STEM, c) defect characterization and d) final clarification of the origin between experimental and calculated HAADF STEM intensities for electron energies below 15 keV for low-density and low-atomic-number materials. Low-energy STEM will be applied to quantify sample properties of different nanoscaled materials.

与第一项目阶段一样，第二项目阶段的总体目标是在电子能量低于30 keV的情况下，对扫描透射电子显微镜（STEM）中的对比度形成进行基础研究。这些能量对于扫描电子显微镜是典型的，扫描电子显微镜可以通过固态STEM检测器进行装配，用于研究电子透明样品。分辨率略优于1 nm，足以解决生命科学、材料科学和纳米技术中的许多问题。低能STEM可以使高电子能量下的精细（S）TEM研究过时，这使得低能STEM成为一种具有成本效益的替代方案。低电子能量的另一个优点是可以忽略不计的撞击损伤。第二个项目阶段的具体目标将是a）轴向透射衍射图案的研究，B）由于多重/多重散射作为低能STEM分辨率的限制因素而导致的样品中的光束展宽，c）缺陷表征和d）最终澄清低密度和低原子序数材料的电子能量低于15 keV的实验和计算HAADF STEM强度之间的起源。低能STEM将被应用于量化不同纳米材料的样品特性。