使用原子尺度振动光谱对同位素扩散进行成像
Ryosuke Senga1, Yung-Chang Lin2, Shigeyuki Morishita3
1Nanomaterials Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Ibaraki, Japan. ryosuke-senga@aist.go.jp.
Nature
|March 3, 2022
概括
这项研究使用振动光谱对石墨烯进行原子级同位素成像. 这项技术成功追踪了碳原子的自我扩散,为纳米级同位素工程铺平了道路.
科学领域:
- 材料科学
- 纳米技术
- 光谱学
背景情况:
- 目前的同位素分析方法具有有限的空间分辨率 (数百纳米).
- 探测原子级同位素一直是一个重大挑战.
- 使用电子探测器的振动光谱提供更高的分辨率,但缺乏原子级同位素检测.
研究的目的:
- 在原子层面实现明确的同位素成像.
- 为了监测石墨烯中碳同位素的自我扩散.
- 建立纳米同位素工程和追踪的新方法.
主要方法:
- 在碳-13 (13C) 石墨烯中生长碳-12 (12C) 原子的域.
- 在600°C时对样品进行火以促进扩散.
- 使用扫描传输电子显微镜-电子能量损失光谱 (STEM-EELS) 进行同位素测绘.
主要成果:
- 在13C石墨烯中实现了12C原子的明确同位素成像.
- 观察到12C原子的快速扩散和分离.
- 石墨烯在2小时内在100纳米区域变得同位素均,这表明碳原子的移动性很高.
结论:
- 原子级振动光谱能够进行精确的同位素成像和扩散监测.
- 这些发现突显了石墨烯中碳原子通过自我扩散的高流动性.
- 这种技术为纳米级同位素工程,标记和跟踪提供了一个基本的工具.
相关概念视频
Atomic Absorption Spectroscopy: Atomization Methods
703
Atomic Absorption Spectroscopy (AAS) atomizes samples through flame atomization or electrothermal atomization. Flame atomization typically involves a nebulizer and spray chamber assembly to combine the sample with a fuel–oxidant mixture, creating a fine aerosol mist that enters a burner. Typically, the fuel and oxidant are combined in an approximately stoichiometric ratio. However, for atoms that are easily oxidized, a fuel-rich mixture may be more advantageous. Only about 5% of the...
703
IR Spectroscopy: Hooke's Law Approximation of Molecular Vibration
1.8K
A covalently bonded heteronuclear diatomic molecule can be modeled as two vibrating masses connected by a spring. The vibrational frequency of the bond can be expressed using an equation derived from Hooke's law, which describes how the force applied to stretch or compress a spring is proportional to the displacement of the spring. In this case, the atoms behave like masses, and the bond acts like a spring.
According to Hooke's law, the vibrational frequency is directly proportional to...
According to Hooke's law, the vibrational frequency is directly proportional to...
1.8K
Atomic Fluorescence Spectroscopy
535
Atomic fluorescence spectroscopy (AFS) is an analytical technique that involves the electronic transitions of atoms in a flame, furnace, or plasma being excited by electromagnetic (EM) radiation. When these atoms absorb energy, they become excited and subsequently release energy as they return to their original state. This emitted light, or "fluorescence," is observed at a right angle to the incident beam. Both absorption and emission processes transpire at distinct wavelengths, which...
535
IR Spectroscopy: Molecular Vibration Overview
3.0K
When Infrared (IR) radiation passes through a covalently bonded molecule, the bonds transition from lower to higher vibrational levels. The fundamental vibrational motions that result in infrared absorption can be classified as stretching or bending vibrations.
Stretching vibrations are vibrational motions that occur along the bond line, changing the bond length or distance between two bonded atoms. They are further distinguished as symmetric or asymmetric. In symmetric stretching, the...
Stretching vibrations are vibrational motions that occur along the bond line, changing the bond length or distance between two bonded atoms. They are further distinguished as symmetric or asymmetric. In symmetric stretching, the...
3.0K
Atomic Absorption Spectroscopy: Interference
1.2K
Interference leads to systematic error in atomic absorption (AA) measurements by enhancing or diminishing the analytical signal or the background. These interferences can be grouped into three main categories: spectral interference, chemical interference, and physical interference.
Spectral interference occurs when signals from other elements or molecules overlap with the analyte signal, falsely elevating or masking the analyte's absorbance. This interference can be corrected using Zeeman,...
Spectral interference occurs when signals from other elements or molecules overlap with the analyte signal, falsely elevating or masking the analyte's absorbance. This interference can be corrected using Zeeman,...
1.2K
Atomic Absorption Spectroscopy: Instrumentation
1.0K
An atomic absorption spectrophotometer (AAS) comprises several components: a radiation source, an atomizer, a monochromator, and a detector. The radiation source can be a hollow-cathode lamp (HCL) or an electrodeless-discharge lamp (EDL), both of which provide a narrow emission line of the required wavelength. However, some instruments use continuum sources and high-resolution monochromators to achieve a narrow range of radiation.
The atomizer used in AAS can be either a flame atomizer or an...
The atomizer used in AAS can be either a flame atomizer or an...
1.0K


