Direct motif extraction from high resolution crystalline STEM images
Ultramicroscopy. 2023 Dec;254:113827. doi: 10.1016/j.ultramic.2023.113827. Epub 2023 Aug 5.ABSTRACTDuring the last decade, automatic data analysis methods concerning different aspects of crystal analysis have been developed, e.g., unsupervised primitive unit cell extraction and automated crystal distortion and defects detection. However, an automatic, unsupervised motif extraction method is still not widely available yet. Here, we propose and demonstrate a novel method for the automatic motif extraction in real space from crystalline images based on a variational approach involving the unit cell projection operator. Due to...
Source: Ultramicroscopy - September 16, 2023 Category: Laboratory Medicine Authors: Amel Shamseldeen Ali Alhassan Siyuan Zhang Benjamin Berkels Source Type: research
Direct motif extraction from high resolution crystalline STEM images
Ultramicroscopy. 2023 Dec;254:113827. doi: 10.1016/j.ultramic.2023.113827. Epub 2023 Aug 5.ABSTRACTDuring the last decade, automatic data analysis methods concerning different aspects of crystal analysis have been developed, e.g., unsupervised primitive unit cell extraction and automated crystal distortion and defects detection. However, an automatic, unsupervised motif extraction method is still not widely available yet. Here, we propose and demonstrate a novel method for the automatic motif extraction in real space from crystalline images based on a variational approach involving the unit cell projection operator. Due to...
Source: Ultramicroscopy - September 16, 2023 Category: Laboratory Medicine Authors: Amel Shamseldeen Ali Alhassan Siyuan Zhang Benjamin Berkels Source Type: research
Direct motif extraction from high resolution crystalline STEM images
Ultramicroscopy. 2023 Dec;254:113827. doi: 10.1016/j.ultramic.2023.113827. Epub 2023 Aug 5.ABSTRACTDuring the last decade, automatic data analysis methods concerning different aspects of crystal analysis have been developed, e.g., unsupervised primitive unit cell extraction and automated crystal distortion and defects detection. However, an automatic, unsupervised motif extraction method is still not widely available yet. Here, we propose and demonstrate a novel method for the automatic motif extraction in real space from crystalline images based on a variational approach involving the unit cell projection operator. Due to...
Source: Ultramicroscopy - September 16, 2023 Category: Laboratory Medicine Authors: Amel Shamseldeen Ali Alhassan Siyuan Zhang Benjamin Berkels Source Type: research
Importance of TEM sample thickness for measuring strain fields
In this study, we conducted a systematic investigation to quantify the influence of TEM sample thickness on the residual strain field using deformed Fe-based and Zr-based metallic glasses as model systems. The samples were gradually thinned from 300 nm to 70 nm, and the same area was examined using 4D-STEM with identical imaging settings. Our results demonstrate that thinning the sample affects the atomic configuration at both the short-range (SR) and medium-range (MR) scales. Consequently, when the sample is thinned too much, it no longer preserves the native deformation structure. These findings highlight the critical im...
Source: Ultramicroscopy - September 14, 2023 Category: Laboratory Medicine Authors: Sangjun Kang Di Wang Christian K übel Xiaoke Mu Source Type: research
Importance of TEM sample thickness for measuring strain fields
In this study, we conducted a systematic investigation to quantify the influence of TEM sample thickness on the residual strain field using deformed Fe-based and Zr-based metallic glasses as model systems. The samples were gradually thinned from 300 nm to 70 nm, and the same area was examined using 4D-STEM with identical imaging settings. Our results demonstrate that thinning the sample affects the atomic configuration at both the short-range (SR) and medium-range (MR) scales. Consequently, when the sample is thinned too much, it no longer preserves the native deformation structure. These findings highlight the critical im...
Source: Ultramicroscopy - September 14, 2023 Category: Laboratory Medicine Authors: Sangjun Kang Di Wang Christian K übel Xiaoke Mu Source Type: research
Importance of TEM sample thickness for measuring strain fields
In this study, we conducted a systematic investigation to quantify the influence of TEM sample thickness on the residual strain field using deformed Fe-based and Zr-based metallic glasses as model systems. The samples were gradually thinned from 300 nm to 70 nm, and the same area was examined using 4D-STEM with identical imaging settings. Our results demonstrate that thinning the sample affects the atomic configuration at both the short-range (SR) and medium-range (MR) scales. Consequently, when the sample is thinned too much, it no longer preserves the native deformation structure. These findings highlight the critical im...
Source: Ultramicroscopy - September 14, 2023 Category: Laboratory Medicine Authors: Sangjun Kang Di Wang Christian K übel Xiaoke Mu Source Type: research
Relation between sampling, sensitivity and precision in strain mapping using the Geometric Phase Analysis method in Scanning Transmission Electron Microscopy
In this study an additional parameter, sampling, is proposed to be analyzed regarding the precision of GPA by developing the concept of a phase noise in the GPA equations. Both experimentally and theoretically, the following article demonstrates how the precision, and the sensitivity of the GPA method is improved when using a larger pixel spacing to record an electron micrograph in Scanning Transmission Electron Microscopy (STEM). The counterintuitive concept of increasing the field of view to improve the GPA precision results is an extension of the application of strain characterization methods in STEM towards low deforma...
Source: Ultramicroscopy - September 10, 2023 Category: Laboratory Medicine Authors: A Pofelski Y Zhu G A Botton Source Type: research
Relation between sampling, sensitivity and precision in strain mapping using the Geometric Phase Analysis method in Scanning Transmission Electron Microscopy
In this study an additional parameter, sampling, is proposed to be analyzed regarding the precision of GPA by developing the concept of a phase noise in the GPA equations. Both experimentally and theoretically, the following article demonstrates how the precision, and the sensitivity of the GPA method is improved when using a larger pixel spacing to record an electron micrograph in Scanning Transmission Electron Microscopy (STEM). The counterintuitive concept of increasing the field of view to improve the GPA precision results is an extension of the application of strain characterization methods in STEM towards low deforma...
Source: Ultramicroscopy - September 10, 2023 Category: Laboratory Medicine Authors: A Pofelski Y Zhu G A Botton Source Type: research
Relation between sampling, sensitivity and precision in strain mapping using the Geometric Phase Analysis method in Scanning Transmission Electron Microscopy
In this study an additional parameter, sampling, is proposed to be analyzed regarding the precision of GPA by developing the concept of a phase noise in the GPA equations. Both experimentally and theoretically, the following article demonstrates how the precision, and the sensitivity of the GPA method is improved when using a larger pixel spacing to record an electron micrograph in Scanning Transmission Electron Microscopy (STEM). The counterintuitive concept of increasing the field of view to improve the GPA precision results is an extension of the application of strain characterization methods in STEM towards low deforma...
Source: Ultramicroscopy - September 10, 2023 Category: Laboratory Medicine Authors: A Pofelski Y Zhu G A Botton Source Type: research
Relation between sampling, sensitivity and precision in strain mapping using the Geometric Phase Analysis method in Scanning Transmission Electron Microscopy
In this study an additional parameter, sampling, is proposed to be analyzed regarding the precision of GPA by developing the concept of a phase noise in the GPA equations. Both experimentally and theoretically, the following article demonstrates how the precision, and the sensitivity of the GPA method is improved when using a larger pixel spacing to record an electron micrograph in Scanning Transmission Electron Microscopy (STEM). The counterintuitive concept of increasing the field of view to improve the GPA precision results is an extension of the application of strain characterization methods in STEM towards low deforma...
Source: Ultramicroscopy - September 10, 2023 Category: Laboratory Medicine Authors: A Pofelski Y Zhu G A Botton Source Type: research
TEM-EDS microanalysis: Comparison among the standardless, Cliff & amp; Lorimer and absorption correction quantification methods
Ultramicroscopy. 2023 Sep 4;254:113845. doi: 10.1016/j.ultramic.2023.113845. Online ahead of print.ABSTRACTAvailable quantification methods for energy dispersive X-ray microanalysis in transmission electron microscopy, such as the standardless method (SLM), the Cliff-Lorimer approximation (CLA) and the absorption correction method (ACM), are compared. As expected, the CLA and ACM give superior results with respect to the SLM. As far as absorption can be considered negligible, CLA and ACM perform similarly. However, starting from mass-thickness of the order of 22 × 10-6 g/cm2, absorption become significant and the ACM give...
Source: Ultramicroscopy - September 9, 2023 Category: Laboratory Medicine Authors: Roberto Conconi Gennaro Ventruti Fernando Nieto Giancarlo Capitani Source Type: research
Edge-induced excitations in Bi < sub > 2 < /sub > Te < sub > 3 < /sub > from spatially-resolved electron energy-gain spectroscopy
Ultramicroscopy. 2023 Sep 4;254:113841. doi: 10.1016/j.ultramic.2023.113841. Online ahead of print.ABSTRACTAmong the many potential applications of topological insulator materials, their broad potential for the development of novel tunable plasmonics at THz and mid-infrared frequencies for quantum computing, terahertz detectors, and spintronic devices is particularly attractive. The required understanding of the intricate relationship between nanoscale crystal structure and the properties of the resulting plasmonic resonances remains, however, elusive for these materials. Specifically, edge- and surface-induced plasmonic r...
Source: Ultramicroscopy - September 9, 2023 Category: Laboratory Medicine Authors: Helena La Abel Brokkelkamp Stijn van der Lippe Jaco Ter Hoeve Juan Rojo Sonia Conesa-Boj Source Type: research
Investigating the effects of solution viscosity on the stability and success rate of SECCM imaging
Ultramicroscopy. 2023 Sep 2;254:113843. doi: 10.1016/j.ultramic.2023.113843. Online ahead of print.ABSTRACTDue to the capability of simultaneously detecting the morphology and electrochemical information of samples and limiting the electrochemical reaction to a range approximately the size of the inner diameter of the pipette tip opening, scanning electrochemical cell microscopy (SECCM) enables higher precision local electrochemical measurement and surface material delivery and has been demonstrating unique advantages and broad application prospects. However, the meniscus droplet at the pipette tip of SECCM is equivalent t...
Source: Ultramicroscopy - September 8, 2023 Category: Laboratory Medicine Authors: Qiangqiang Zheng Jian Zhuang Tianying Wang Xiaobo Liao Lei Cheng Shengbo Gu Source Type: research
Investigating the effects of solution viscosity on the stability and success rate of SECCM imaging
Ultramicroscopy. 2023 Sep 2;254:113843. doi: 10.1016/j.ultramic.2023.113843. Online ahead of print.ABSTRACTDue to the capability of simultaneously detecting the morphology and electrochemical information of samples and limiting the electrochemical reaction to a range approximately the size of the inner diameter of the pipette tip opening, scanning electrochemical cell microscopy (SECCM) enables higher precision local electrochemical measurement and surface material delivery and has been demonstrating unique advantages and broad application prospects. However, the meniscus droplet at the pipette tip of SECCM is equivalent t...
Source: Ultramicroscopy - September 8, 2023 Category: Laboratory Medicine Authors: Qiangqiang Zheng Jian Zhuang Tianying Wang Xiaobo Liao Lei Cheng Shengbo Gu Source Type: research
Scanning capacitance microscopy of GaN-based high electron mobility transistor structures: A practical guide
Ultramicroscopy. 2023 Aug 22;254:113833. doi: 10.1016/j.ultramic.2023.113833. Online ahead of print.ABSTRACTThe scanning capacitance microscope (SCM) is a powerful tool to characterise local electrical properties in GaN-based high electron mobility transistor (HEMT) structures with nanoscale resolution. We investigated the experimental setup and the imaging conditions to optimise the SCM contrast. As to the experimental setup, we show that the desired tip should be sharp (e.g., with the tip radius of ≤25nm) and its coating should be made of conductive doped diamond. Most importantly, its spring constant should be large t...
Source: Ultramicroscopy - September 4, 2023 Category: Laboratory Medicine Authors: Chen Chen Saptarsi Ghosh Francesca Adams Menno J Kappers David J Wallis Rachel A Oliver Source Type: research
