相关实验视频
Updated: Jan 15, 2026
15:04
Picometer-Precision Atomic Position Tracking through Electron Microscopy
Published on: July 3, 2021
8.3K
在低温和信号有限条件下用于原子分辨率光谱绘图的直接电子检测
Berit H Goodge1, Lena F Kourkoutis2
1School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853, USA; Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, NY 14853, USA; Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany.
Micron (Oxford, England : 1993)
|October 7, 2025
概括
直接电子探测器 (DED) 通过电子能量损失光谱 (STEM-EELS) 映射来增强低温扫描传输电子显微镜. DED可以改善低信号实验的信号噪声,使得原子分辨率元素的快速映射成为可能.
科学领域:
- 材料物理 材料物理
- 生物系统 生物系统
- 固体液体接口 固体液体接口
背景情况:
- 使用STEM-EELS在低温下进行光谱绘图正在扩展到新的研究领域.
- 由于样本灵敏度或采集时间的信号限制可能会阻碍这些实验.
- 直接电子探测器 (DED) 与传统的电荷合装置 (CCD) 相比,具有优势,包括更高的探测量子效率和更好的信号噪声比率.
研究的目的:
- 为了比较Gatan K2 Summit DED与Gatan UltraScan 1000 CCD的性能,用于信号有限的EELS实验.
- 评估DEDs对于低温原子分辨率元素映射的适用性.
主要方法:
- 在STEM-EELS实验中对DED和CCD进行比较性能分析.
- 评估能量分辨率,信号噪声比和原子柱对比度.
- 使用DEDs在冷温度下进行原子分辨率元素映射的演示.
主要成果:
- DED实现了与CCD相比较的能量分辨率,分散率低5倍,从而实现了更广泛的能量范围.
- DEDs促进了低信号实验,包括轻微和高能边缘的快速映射.
- 与CCD相比,使用DED获得的元素地图在低停留时间时呈现出较高的原子柱对比度.
结论:
- 通过克服信号限制,DED显著增强了冷性STEM-EELS.
- 由于DED的性能提高,可以进行先进的低信号实验和快速的原子分辨率元素映射.
- 这一进步为材料物理学,生物系统和接口科学领域的研究开辟了新的可能性.
相关概念视频
01:28Cryo-electron Microscopy
4.1K
Conventional electron microscopy (EM) involves dehydration, fixation, and staining of biological samples, which distorts the native state of biological molecules and results in several artifacts. Also, the high-energy electron beam damages the sample and makes it difficult to obtain high-resolution images. These issues can be addressed using cryo-EM, which uses frozen samples and gentler electron beams. The technique was developed by Jacques Dubochet, Joachim Frank, and Richard Henderson, for...
4.1K
01:20Atomic Emission Spectroscopy: Overview
3.5K
Atomic emission spectroscopy (AES) is an analytical technique used to determine the elemental composition of a sample by analyzing the light emitted from excited atoms. In AES, atoms in a sample are excited to higher energy levels by thermal energy from high-temperature sources, such as plasma, arcs, or sparks. When these excited atoms return to lower energy states, they emit light at specific wavelengths characteristic of each element. The resulting atomic emission spectrum, which consists of...
3.5K
01:29Atomic Emission Spectroscopy: Lab
565
AES is a powerful analytical technique, especially effective when used with plasma sources, producing abundant spectra in characteristic emission lines. The Inductively Coupled Plasma (ICP), in particular, yields superior quantitative analytical data due to its high stability, low noise, low background, and minimal interferences under optimal experimental conditions. However, newer air-operated microwave sources are emerging as promising alternatives that could be more cost-effective than...
565