在SEM实验中测量电子束诱导的样本加热
Christina Koenig1, Alice Bastos da Silva Fanta1, Joerg R Jinschek1
1National Centre for Nano Fabrication and Characterization (DTU Nanolab), Technical University of Denmark (DTU), Kgs Lyngby, Denmark.
Ultramicroscopy
|June 14, 2025
概括
在扫描电子显微镜 (SEM) 过程中,电子束加热可能会影响样品. 这项研究量化了高达70°C的温度升高,这对于电子反射衍射 (EBSD) 分析至关重要.
科学领域:
- 材料科学 材料科学 材料科学
- 分析化学 分析化学
- 物理 物理学 物理
背景情况:
- 扫描电子显微镜 (SEM) 通过电子反射衍射 (EBSD) 提供高分辨率成像和晶体分析.
- 在SEM中,高能电子束可能会导致局部加热,在扩展分析期间可能会损害样本完整性.
- 了解和量化这种电子束诱导的加热对于准确的材料表征至关重要.
研究的目的:
- 在模型金属样本 (铁) 上研究和量化电子束诱导的加热效应.
- 为了确定各种实验参数对局部样本温度的影响.
- 用模拟数据验证实验测量结果.
主要方法:
- 使用基于MEMS的加热装置直接测量局部沉积的电子束能量.
- 通过蒙特卡洛 (MC) 和有限元法 (FEM) 模拟进行验证.
- 实验参数的系统变化:加速电压 (5-30 kV),光束电流 (0.17-22 nA),停留时间 (1μs-1 ms) 和样本倾斜率 (0°-70°).
主要成果:
- 在电子反射衍射 (EBSD) 实验中,观察到本地样本温度增加了高达70°C.
- 影响温度增加的主要实验参数是光束电流和加速电压.
- 梁电流对局部加热产生了最显著的影响.
结论:
- 电子束加热是SEM/EBSD实验中的一个重要因素,需要仔细选择参数.
- 通过结合实验和模拟方法,可以准确量化加热效应.
- 根据这些发现优化实验条件可以保护样本的完整性并提高数据可靠性.
相关概念视频
Preparation of Samples for Electron Microscopy
5.4K
To be visualized by an electron microscope, either transmission or scanning, biological samples need to be fixed (stabilized) so the electron beam does not destroy them and dried thoroughly (desiccated/dehydrated) so the vacuum does not affect them. Fixation needs to be done as quickly as possible because the sample properties will start changing as soon as it is removed from its natural environment. For example, in a tissue sample, the oxygen levels begin decreasing, causing an altered...
5.4K
Scanning Electron Microscopy
4.2K
A scanning electron microscope (SEM) is used to study the surface features of a sample by using an electron beam that scans the sample surface in a two-dimensional manner. Typically, areas between ~1 centimeter to 5 micrometers in width can be imaged. SEM can be used to image bacteria, viruses, tissues as well as larger samples like insects. Conventional SEM gives a magnification ranging from 20X to 30,000X and spatial resolution of 50 to 100 nanometers.
Fundamental Principles
Accelerated...
Fundamental Principles
Accelerated...
4.2K
Overview of Electron Microscopy
8.6K
The wavelengths of visible light ultimately limit the maximum theoretical resolution of images created by light microscopes. Most light microscopes can only magnify 1000X, and a few can magnify up to 1500X. Electrons, like electromagnetic radiation, can behave like waves, but with wavelengths of 0.005 nm, they produce significantly greater resolution up to 0.05 nm as compared to 500 nm for visible light. An electron microscope (EM) can create a sharp image that is magnified up to 2,000,000X.
8.6K
Transmission Electron Microscopy
5.4K
In 1931, physicist Ernst Ruska—building on the idea that magnetic fields can direct an electron beam just as lenses can direct a beam of light in an optical microscope—developed the first prototype of the electron microscope. This development led to the development of the field of electron microscopy. In the transmission electron microscope (TEM), electrons are produced by a hot tungsten element and accelerated by a potential difference in an electron gun, which gives them up to 400...
5.4K


