Quantitative atomic cross section analysis by 4D-STEM and EELS
We describe the fundamental mechanism of plasmon excitation in insulators as a two-step interaction process with a fast electron. First, a target electron in the specimen is excited, the probability for which follows from the availability of atomic transitions, with a strong dependence on the column of the periodic table. Second, the dielectric response of the material determines the energy loss. The energy of the loss peak depends primarily on the valence electrons. Elastic scattering is dominant at higher angles, and can be fitted conveniently to 1/θ3.7 with a linear dependence on atomic number for light atoms. In order...
Source: Ultramicroscopy - February 15, 2024 Category: Laboratory Medicine Authors: Shahar Seifer Lothar Houben Michael Elbaum Source Type: research
Framework of compressive sensing and data compression for 4D-STEM
Ultramicroscopy. 2024 Feb 10;259:113938. doi: 10.1016/j.ultramic.2024.113938. Online ahead of print.ABSTRACTFour-dimensional Scanning Transmission Electron Microscopy (4D-STEM) is a powerful technique for high-resolution and high-precision materials characterization at multiple length scales, including the characterization of beam-sensitive materials. However, the field of view of 4D-STEM is relatively small, which in absence of live processing is limited by the data size required for storage. Furthermore, the rectilinear scan approach currently employed in 4D-STEM places a resolution- and signal-dependent dose limit for t...
Source: Ultramicroscopy - February 15, 2024 Category: Laboratory Medicine Authors: Hsu-Chih Ni Renliang Yuan Jiong Zhang Jian-Min Zuo Source Type: research
Fast detection of micro-objects using scanning electrochemical microscopy based on visual recognition and machine learning
Ultramicroscopy. 2024 Feb 14;259:113937. doi: 10.1016/j.ultramic.2024.113937. Online ahead of print.ABSTRACTScanning electrochemical microscopy (SECM) is a scanning probe microscope with an ultramicroelectrode (UME) as a probe. The technique is advantageous in the characterization of the electrochemical properties of surfaces. However, the limitations, such as slow imaging and many functions depending on the user, only allow us to use some of the possibilities. Therefore, we applied visual recognition and machine learning to detect micro-objects from the image and determine their electrochemical activity. The reconstructio...
Source: Ultramicroscopy - February 15, 2024 Category: Laboratory Medicine Authors: Vadimas Ivinskij Antanas Zinovicius Andrius Dzedzickis Jurga Subaciute-Zemaitiene Juste Rozene Vytautas Bucinskas Eugenijus Macerauskas Sonata Tolvaisiene Inga Morkvenaite-Vilkonciene Source Type: research
Quantitative atomic cross section analysis by 4D-STEM and EELS
We describe the fundamental mechanism of plasmon excitation in insulators as a two-step interaction process with a fast electron. First, a target electron in the specimen is excited, the probability for which follows from the availability of atomic transitions, with a strong dependence on the column of the periodic table. Second, the dielectric response of the material determines the energy loss. The energy of the loss peak depends primarily on the valence electrons. Elastic scattering is dominant at higher angles, and can be fitted conveniently to 1/θ3.7 with a linear dependence on atomic number for light atoms. In order...
Source: Ultramicroscopy - February 15, 2024 Category: Laboratory Medicine Authors: Shahar Seifer Lothar Houben Michael Elbaum Source Type: research
Framework of compressive sensing and data compression for 4D-STEM
Ultramicroscopy. 2024 Feb 10;259:113938. doi: 10.1016/j.ultramic.2024.113938. Online ahead of print.ABSTRACTFour-dimensional Scanning Transmission Electron Microscopy (4D-STEM) is a powerful technique for high-resolution and high-precision materials characterization at multiple length scales, including the characterization of beam-sensitive materials. However, the field of view of 4D-STEM is relatively small, which in absence of live processing is limited by the data size required for storage. Furthermore, the rectilinear scan approach currently employed in 4D-STEM places a resolution- and signal-dependent dose limit for t...
Source: Ultramicroscopy - February 15, 2024 Category: Laboratory Medicine Authors: Hsu-Chih Ni Renliang Yuan Jiong Zhang Jian-Min Zuo Source Type: research
Fast detection of micro-objects using scanning electrochemical microscopy based on visual recognition and machine learning
Ultramicroscopy. 2024 Feb 14;259:113937. doi: 10.1016/j.ultramic.2024.113937. Online ahead of print.ABSTRACTScanning electrochemical microscopy (SECM) is a scanning probe microscope with an ultramicroelectrode (UME) as a probe. The technique is advantageous in the characterization of the electrochemical properties of surfaces. However, the limitations, such as slow imaging and many functions depending on the user, only allow us to use some of the possibilities. Therefore, we applied visual recognition and machine learning to detect micro-objects from the image and determine their electrochemical activity. The reconstructio...
Source: Ultramicroscopy - February 15, 2024 Category: Laboratory Medicine Authors: Vadimas Ivinskij Antanas Zinovicius Andrius Dzedzickis Jurga Subaciute-Zemaitiene Juste Rozene Vytautas Bucinskas Eugenijus Macerauskas Sonata Tolvaisiene Inga Morkvenaite-Vilkonciene Source Type: research
Quantitative atomic cross section analysis by 4D-STEM and EELS
We describe the fundamental mechanism of plasmon excitation in insulators as a two-step interaction process with a fast electron. First, a target electron in the specimen is excited, the probability for which follows from the availability of atomic transitions, with a strong dependence on the column of the periodic table. Second, the dielectric response of the material determines the energy loss. The energy of the loss peak depends primarily on the valence electrons. Elastic scattering is dominant at higher angles, and can be fitted conveniently to 1/θ3.7 with a linear dependence on atomic number for light atoms. In order...
Source: Ultramicroscopy - February 15, 2024 Category: Laboratory Medicine Authors: Shahar Seifer Lothar Houben Michael Elbaum Source Type: research
Framework of compressive sensing and data compression for 4D-STEM
Ultramicroscopy. 2024 Feb 10;259:113938. doi: 10.1016/j.ultramic.2024.113938. Online ahead of print.ABSTRACTFour-dimensional Scanning Transmission Electron Microscopy (4D-STEM) is a powerful technique for high-resolution and high-precision materials characterization at multiple length scales, including the characterization of beam-sensitive materials. However, the field of view of 4D-STEM is relatively small, which in absence of live processing is limited by the data size required for storage. Furthermore, the rectilinear scan approach currently employed in 4D-STEM places a resolution- and signal-dependent dose limit for t...
Source: Ultramicroscopy - February 15, 2024 Category: Laboratory Medicine Authors: Hsu-Chih Ni Renliang Yuan Jiong Zhang Jian-Min Zuo Source Type: research
Fast detection of micro-objects using scanning electrochemical microscopy based on visual recognition and machine learning
Ultramicroscopy. 2024 Feb 14;259:113937. doi: 10.1016/j.ultramic.2024.113937. Online ahead of print.ABSTRACTScanning electrochemical microscopy (SECM) is a scanning probe microscope with an ultramicroelectrode (UME) as a probe. The technique is advantageous in the characterization of the electrochemical properties of surfaces. However, the limitations, such as slow imaging and many functions depending on the user, only allow us to use some of the possibilities. Therefore, we applied visual recognition and machine learning to detect micro-objects from the image and determine their electrochemical activity. The reconstructio...
Source: Ultramicroscopy - February 15, 2024 Category: Laboratory Medicine Authors: Vadimas Ivinskij Antanas Zinovicius Andrius Dzedzickis Jurga Subaciute-Zemaitiene Juste Rozene Vytautas Bucinskas Eugenijus Macerauskas Sonata Tolvaisiene Inga Morkvenaite-Vilkonciene Source Type: research
Energy-dispersive X-ray spectroscopy in a low energy electron microscope
Ultramicroscopy. 2024 Feb 6;259:113935. doi: 10.1016/j.ultramic.2024.113935. Online ahead of print.ABSTRACTEnergy-Dispersive X-Ray Spectroscopy (EDS) is a technique frequently used in Scanning and Transmission Electron Microscopes to study the elemental composition of a sample. Briefly, high energy electrons of the incident electron beam may ionize an electron from a core shell. The decay of this excited state may result in the emission of a characteristic X-ray photon or Auger-Meitner electron. A solid-state EDS detector captures the X-ray photon and determines its energy. The energy spectrum thus contains information on ...
Source: Ultramicroscopy - February 8, 2024 Category: Laboratory Medicine Authors: Rudolf M Tromp Source Type: research
High precision orientation mapping from 4D-STEM precession electron diffraction data through quantitative analysis of diffracted intensities
Ultramicroscopy. 2024 Jan 24;259:113927. doi: 10.1016/j.ultramic.2024.113927. Online ahead of print.ABSTRACTThe association of scanning transmission electron microscopy (STEM) and detection of a diffraction pattern at each probe position (so-called 4D-STEM) represents one of the most promising approaches to analyze structural properties of materials with nanometric resolution and low irradiation levels. This is widely used for texture analysis of materials using automated crystal orientation mapping (ACOM). Herein, we perform orientation mapping in InP nanowires exploiting precession electron diffraction (PED) patterns acq...
Source: Ultramicroscopy - February 8, 2024 Category: Laboratory Medicine Authors: Leonardo M Corr êa Eduardo Ortega Arturo Ponce M ônica A Cotta Daniel Ugarte Source Type: research
X-ray production cross sections for Ir and Bi M-subshells induced by electron impact
Ultramicroscopy. 2024 Jan 24;259:113923. doi: 10.1016/j.ultramic.2024.113923. Online ahead of print.ABSTRACTM-subshell X-ray production cross sections were indirectly measured for Ir and Bi targets irradiated with monoenergetic electron beams. The projectile energy range ran from 2.2 to 28 keV, impinging on Ir and Bi pure bulk targets in a scanning electron microscope. The resulting X-ray emission spectra were acquired with an energy dispersive spectrometer, and processed afterwards by means of a robust parameter optimization procedure developed previously. X-ray production cross sections were finally obtained through an a...
Source: Ultramicroscopy - February 7, 2024 Category: Laboratory Medicine Authors: M D D écima G E Castellano J C Trincavelli A C Carreras Source Type: research
Correction of step size dependency in local misorientation obtained by EBSD measurements: Introducing equidistant local misorientation
This study proposed the concept of an equidistant local misorientation, for which surrounding points at the same point distance from the target point were selected to calculate misorientation. An arbitrary point distance can be set for the equidistant local misorientation regardless of the step size. The changes in equidistant local misorientation for various point distances were calculated for the crystal orientation datasets obtained with different step sizes and measurement grids (square or hexagonal) using Type 316 stainless steel specimens, in which plastic strain of about 5 % was induced. It was shown that the equidi...
Source: Ultramicroscopy - February 4, 2024 Category: Laboratory Medicine Authors: Masayuki Kamaya Source Type: research
Automatic center identification of electron diffraction with multi-scale transformer networks
Ultramicroscopy. 2024 Jan 24;259:113926. doi: 10.1016/j.ultramic.2024.113926. Online ahead of print.ABSTRACTSelected area electron diffraction (SAED) is a widely used technique for characterizing the structure and measuring lattice parameters of materials. An autonomous analytic method has become an urgent demand for the large-scale SAED data produced from in-situ experiments. In this work, we realize the automatic processing for center identification with a proposed deep segmentation model named the multi-scale Transformer (MS-Trans) network. This algorithm enables robust segmentation of the central spots by combining a n...
Source: Ultramicroscopy - February 4, 2024 Category: Laboratory Medicine Authors: Mengshu Ge Yue Pan Xiaozhi Liu Zhicheng Zhao Dong Su Source Type: research
Accurate and fast localization of EBSD pattern centers for screen moving technology
Ultramicroscopy. 2024 Jan 20;259:113924. doi: 10.1016/j.ultramic.2024.113924. Online ahead of print.ABSTRACTThe authors of this study develop an accurate and fast method for the localization of the pattern centers (PCs) in the electron backscatter diffraction (EBSD) technique by using the model of deformation of screen moving technology. The proposed algorithm is divided into two steps: (a) Approximation: We use collinear feature points to obtain the initial value of the coordinates of the PC and the zoom factor. (b) Subdivision: We then construct a deformation function containing the three parameters to be solved, select ...
Source: Ultramicroscopy - February 3, 2024 Category: Laboratory Medicine Authors: Wei Li Xingui Zhou Jingchao Xu Ruyue Zhang Lizhao Lai Yi Zeng Hong Miao Source Type: research
