通过洛伦茨 (扫描) 传输电子显微镜对磁性纳米结构进行定量相位检索和表征
Kayna L Mendoza1,2, Haoyang Ni3, Georgios Varnavides4,5
1Department of Materials Science and Engineering, Northwestern University, Evanston, IL, United States of America.
概括
新的阶段检索方法,反向模式自动分化 (RMAD) 和扩展电子图谱代引擎 (ePIE) 提供了对磁性纳米材料的增强分析. 这些技术应用于Permalloy纳米结构,提供高分辨率成像和磁性特性的表征.
科学领域:
- 材料科学 材料科学 材料科学
- 凝聚物质物理学 凝聚物质物理学
- 电子显微镜电子显微镜
背景情况:
- 传统的相重建方法,如离轴全息 (OAH) 和传输强度方程 (TIE),在分析纳米磁性材料方面存在局限性.
- 计算能力和算法的进步使相位检索具有更高的分辨率和效率.
研究的目的:
- 评估和比较磁性材料的相检索技术,包括TIE,RMAD和EPIE.
- 展示这些方法用于重建磁性结构和确定材料性能的应用.
- 用先进的相位检索分析磁性纳米结构中的近距离效应.
主要方法:
- 使用TIE,RMAD和EPIE进行永久合金 (Ni80Fe20) 纳米级岛屿的模拟.
- 在LTEM中使用OAH和RMAD进行NiFe纳米线的实验阶段检索和图像重建.
- 在洛伦茨模式-4D扫描传输电子显微镜中应用 ePIE.
- 微磁建模用于证实和磁化.
主要成果:
- 纳米级磁性材料的相位检索和图像重建成功.
- 在LTEM和4DSTEM实验中展示RMAD和ePIE的有效性.
- 通过与微磁模型进行比较来确定和磁化.
- 磁纳米结构中近距离效应的表征.
结论:
- RMAD和ePIE是磁性纳米材料中全相检索的有效先进方法.
- 这些技术提供了高分辨率成像和磁纳米结构的详细表征.
- 这项研究强调了高级阶段检索对于理解磁现象 (如近距离效应) 的有用性.
更多相关视频
相关概念视频
01:14NMR Spectrometers: Resolution and Error Correction
994
When magnetic nuclei in a sample achieve resonance and undergo relaxation, the signal detected in NMR is an approximately exponential free induction decay. Fourier transform of an exponential decay yields a Lorentzian peak in the frequency domain. Lorentzian peaks in an NMR spectrum are defined by their amplitude, full width at half maximum, and position, where the peak width is governed by the spin-spin relaxation time alone. In real experiments, however, the applied magnetic field is rendered...
994
01:07Scanning Electron Microscopy
5.1K
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...
5.1K
01:15Transmission Electron Microscopy
6.1K
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...
6.1K
01:07Electron Microscope Tomography and Single-particle Reconstruction
2.1K
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...
2.1K
01:22Overview of Microscopy Techniques
10.8K
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...
10.8K