TEM-EDS微分析:不同电子源,加速电压和检测系统之间的比较
Roberto Conconi1, María Del Mar Abad Ortega2, Fernando Nieto3
1Department of Earth and Environmental Sciences, University of Milano-Bicocca, Piazza della Scienza 4, Milano 2016, Italy; Université de Lille, CNRS, INRAE, Centrale Lille, UMR 8207-UMET-Unité Matériaux et Transformations, Lille F-59000, France.
Ultramicroscopy
|June 24, 2025
概括
传输电子显微镜-能量分散光谱 (TEM-EDS) 校准是特定于仪器的. 不同的TEM和EDS系统产生独特的k因子,影响元素定量精度.
科学领域:
- 材料科学 材料科学 材料科学
- 分析化学 分析化学
- 显微镜的使用方法
背景情况:
- 使用传输电子显微镜与能量分散光谱 (TEM-EDS) 精确的元素定量对于材料分析至关重要.
- 现有的量化方法,如Cliff和Lorimer近似和吸收校正,依赖于精确的校准和k因子.
- 传输电子显微镜 (TEM) 仪器和能量分散光谱 (EDS) 系统的变化可能会影响量化结果.
研究的目的:
- 为了比较两个TEM-EDS量化方法的性能:Cliff和Lorimer近似和吸收校正.
- 评估不同TEM仪器 (源类型,加速电压) 和EDS系统 (4列式与单个SDD) 对量化结果的影响.
- 为了确定不同仪器和EDS系统组合的k因子的特异性.
主要方法:
- 采用了两种定量方法:基于电子中立性的Cliff和Lorimer近似和吸收校正.
- 通过使用三个不同的TEM进行分析,具有不同的源类型 (场辐射与热电) 和加速电压 (200与300kV).
- 使用四列漂移探测器 (SDD) 和单个SDD系统进行EDS分析.
主要成果:
- EDS校准是严格的仪器特定;普遍有效的k因子不存在,需要系统特定的k因子集.
- 与单个SDD相比,四列SDD系统的效率更高,检测极限更低,因为敏感区域较大.
- 与传统来源相比,现场发射炮TEM (FEG-TEM) 显示,与传统来源相比,弱键元素的辐射诱导迁移减少,这是由于点尺寸较小和每原子电子剂量较低.
结论:
- 对于厚度和/或密度较高的样品,建议采用吸收校正方法,而Cliff和Lorimer近似方法则适用于其他情况下更简单,更快速的分析.
- 这项研究强调了为更轻,更密的化合物确定不同的kO/Si因子的必要性.
- 在TEM-EDS中精确的元素量化需要仔细考虑仪器特定参数和适当的方法选择.
相关概念视频
Transmission Electron Microscopy
5.9K
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...
5.9K
Overview of Electron Microscopy
10.7K
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.
10.7K
Scanning Electron Microscopy
4.4K
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...
4.4K
Electron Microscope Tomography and Single-particle Reconstruction
2.6K
Transmission electron microscopy (TEM) can be used to determine the 3D structure of biological samples with the help of techniques such as electron microscope tomography and single-particle reconstruction. While single-particle reconstruction can examine macromolecules and macromolecular complexes in vitro conditions only, tomography permits the study of cell components or small cells in vivo.
Electron Tomography
Electron tomography can be performed either in TEM or STEM (scanning transmission...
Electron Tomography
Electron tomography can be performed either in TEM or STEM (scanning transmission...
2.6K
Overview of Microscopy Techniques
12.6K
The early pioneers of microscopy opened a window into the invisible world of microorganisms. In 1830, Joseph Jackson Lister created an essentially modern light microscope. The 20th century saw the development of microscopes that leveraged nonvisible light, such as fluorescence microscopy that uses an ultraviolet light source and electron microscopy that uses short-wavelength electron beams. These advances significantly improved magnification, image resolution, and contrast. By comparison, the...
12.6K
Preparation of Samples for Electron Microscopy
5.9K
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...
5.9K


