Pub Date : 2025-11-30DOI: 10.1016/j.ultramic.2025.114292
Ovidiu Cretu, Koji Kimoto
We report on the development of a new 100 MHz high-speed scan controller for the electron microscope, using programmable hardware. By using a spiral scan pattern in order to work around the limitations of the scan coils, we show that this controller is able to acquire undistorted images with a frame time of 0.9 ms. The controller’s scan signal and timing control is used to optimize regular (sawtooth) scanning, in order to reduce image distortions at high speeds. Finally, we implement a dose-driven acquisition method, which lowers the required dose and optimizes its distribution, while maintaining the contrast mechanism of the detector.
{"title":"Development of a 100 MHz scan controller for the electron microscope","authors":"Ovidiu Cretu, Koji Kimoto","doi":"10.1016/j.ultramic.2025.114292","DOIUrl":"10.1016/j.ultramic.2025.114292","url":null,"abstract":"<div><div>We report on the development of a new 100 MHz high-speed scan controller for the electron microscope, using programmable hardware. By using a spiral scan pattern in order to work around the limitations of the scan coils, we show that this controller is able to acquire undistorted images with a frame time of 0.9 ms. The controller’s scan signal and timing control is used to optimize regular (sawtooth) scanning, in order to reduce image distortions at high speeds. Finally, we implement a dose-driven acquisition method, which lowers the required dose and optimizes its distribution, while maintaining the contrast mechanism of the detector.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"281 ","pages":"Article 114292"},"PeriodicalIF":2.0,"publicationDate":"2025-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145693176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-29DOI: 10.1016/j.ultramic.2025.114280
Lei Yu , Weishi Wan , Xiaodong Yang , Meng Li , Takanori Koshikawa , Masahiko Suzuki , Tsuneo Yasue , Xiuguang Jin , Yoshikazu Takeda , Rudolf M. Tromp , Yaowen Liu , Hans-Joachim Elmers , Wen-Xin Tang
Magnetic structures down to the nanometer scale have drawn increasing attention due to their fundamental interests and potential applications. In general, the magnetic structure of a system tends to stay in the state with the lowest energy as different interactions compete with each other. Here we report the direct observation of a meta-stable Omega state with double vortices of the same circularity in a nanoscale Fe island on a W(110) substrate. The process indicates that this metastable state is formed by two isolated islands merging during annealing, while keeping their original vortex state. Micromagnetic simulations confirm the possibility of this metastable state.
{"title":"Direct observation of meta-stable magnetization states in Fe/W(110) nanostructures","authors":"Lei Yu , Weishi Wan , Xiaodong Yang , Meng Li , Takanori Koshikawa , Masahiko Suzuki , Tsuneo Yasue , Xiuguang Jin , Yoshikazu Takeda , Rudolf M. Tromp , Yaowen Liu , Hans-Joachim Elmers , Wen-Xin Tang","doi":"10.1016/j.ultramic.2025.114280","DOIUrl":"10.1016/j.ultramic.2025.114280","url":null,"abstract":"<div><div>Magnetic structures down to the nanometer scale have drawn increasing attention due to their fundamental interests and potential applications. In general, the magnetic structure of a system tends to stay in the state with the lowest energy as different interactions compete with each other. Here we report the direct observation of a meta-stable Omega state with double vortices of the same circularity in a nanoscale Fe island on a W(110) substrate. The process indicates that this metastable state is formed by two isolated islands merging during annealing, while keeping their original vortex state. Micromagnetic simulations confirm the possibility of this metastable state.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"281 ","pages":"Article 114280"},"PeriodicalIF":2.0,"publicationDate":"2025-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145693175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Atomic Force Microscopy (AFM), as a scanning probe microscopy technique, has been extensively utilized for nanoscale structural characterization, mechanical property quantification, and in-situ electromagnetic field measurements with high spatial resolution. However, the primary limitations hindering the widespread application of AFM include its relatively low scanning velocity, intricate parameter optimization requirements, and the necessity for highly skilled operators to achieve optimal imaging resolution. In this paper, a novel fuzzy amplitude-modulated PI (Proportional-Integral) control methodology is proposed for AFM adaptive control systems, incorporating dynamically adjusted proportional and integral gain parameters to effectively mitigate measurement inaccuracies. Experimental characterization demonstrates that the proposed fuzzy control scheme effectively confines amplitude error to approximately 60 pm under operational conditions of 10 Hz scan rate and 40 μm scan size. This methodology establishes a systematic framework for optimizing parameter configuration in AFM, while simultaneously addressing the critical challenge of achieving high-speed performance in scanning probe microscopy applications.
{"title":"Fast tapping mode atomic force microscopy based on fuzzy PI controller","authors":"Lijia Ji , Renjie Gui , Jinbo Chen , Xuhui Zhang , Gengliang Chen","doi":"10.1016/j.ultramic.2025.114281","DOIUrl":"10.1016/j.ultramic.2025.114281","url":null,"abstract":"<div><div>Atomic Force Microscopy (AFM), as a scanning probe microscopy technique, has been extensively utilized for nanoscale structural characterization, mechanical property quantification, and in-situ electromagnetic field measurements with high spatial resolution. However, the primary limitations hindering the widespread application of AFM include its relatively low scanning velocity, intricate parameter optimization requirements, and the necessity for highly skilled operators to achieve optimal imaging resolution. In this paper, a novel fuzzy amplitude-modulated PI (Proportional-Integral) control methodology is proposed for AFM adaptive control systems, incorporating dynamically adjusted proportional and integral gain parameters to effectively mitigate measurement inaccuracies. Experimental characterization demonstrates that the proposed fuzzy control scheme effectively confines amplitude error to approximately 60 pm under operational conditions of 10 Hz scan rate and 40 μm scan size. This methodology establishes a systematic framework for optimizing parameter configuration in AFM, while simultaneously addressing the critical challenge of achieving high-speed performance in scanning probe microscopy applications.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"281 ","pages":"Article 114281"},"PeriodicalIF":2.0,"publicationDate":"2025-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145651725","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-24DOI: 10.1016/j.ultramic.2025.114282
Aaditya Bhat, Colin Gilgenbach, Junghwa Kim, Michael Xu, Menglin Zhu, James M. LeBeau
Here, we evaluate multislice electron ptychography as a tool for depth-resolved atomic-resolution characterization of point defects, using silicon carbide as a case study. Through multislice electron scattering simulations and multislice ptychographic reconstructions, we investigate the phase contrast arising from individual silicon vacancies, antisite defects, and a wide range of substitutional transition metal dopants (VSi to WSi), as well as their potential detectability. Simulating defect types, positions, and microscope conditions, we show that isolated point defects can be located within a unit cell along the sample’s depth. The influence of electron energy, dose, defocus, and convergence semi-angle is also explored to determine their role in governing defect contrast. These results guide experiments aimed at analyzing point defects using multislice electron ptychography.
{"title":"Sensitivity of multislice electron ptychography to point defects: A case study in SiC","authors":"Aaditya Bhat, Colin Gilgenbach, Junghwa Kim, Michael Xu, Menglin Zhu, James M. LeBeau","doi":"10.1016/j.ultramic.2025.114282","DOIUrl":"10.1016/j.ultramic.2025.114282","url":null,"abstract":"<div><div>Here, we evaluate multislice electron ptychography as a tool for depth-resolved atomic-resolution characterization of point defects, using silicon carbide as a case study. Through multislice electron scattering simulations and multislice ptychographic reconstructions, we investigate the phase contrast arising from individual silicon vacancies, antisite defects, and a wide range of substitutional transition metal dopants (V<sub>Si</sub> to W<sub>Si</sub>), as well as their potential detectability. Simulating defect types, positions, and microscope conditions, we show that isolated point defects can be located within a unit cell along the sample’s depth. The influence of electron energy, dose, defocus, and convergence semi-angle is also explored to determine their role in governing defect contrast. These results guide experiments aimed at analyzing point defects using multislice electron ptychography.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"280 ","pages":"Article 114282"},"PeriodicalIF":2.0,"publicationDate":"2025-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145615331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-24DOI: 10.1016/j.ultramic.2025.114284
Austin Irish , Lukas Hrachowina , David Alcer , Magnus Borgström , Rainer Timm
Surface physics play an outsized role in nanostructured electronic devices such as solar cells. Semiconductor nanowires are perfect candidates for advanced solar cells due to their outstanding light absorption properties and their flexibility in axially stacking materials of different doping and band gap. Due to nanowire geometry, however, their surfaces dominate device performance and at the same time are challenging to investigate. Kelvin probe force microscopy (KPFM), an atomic force microscopy (AFM)-based method, provides a unique structural and electrical characterization even in unconventional 3D geometries. We demonstrate a high-resolution, non-destructive AFM technique for directly measuring nanowires within an array and still on their growth substrate. This in situ approach ensures measurement integrity and relevance while preserving the structures for subsequent measurement and processing. When compared with electron beam-induced current, cross-sectional KPFM is both more surface sensitive and less destructive. Utilizing such a cross-sectional approach facilitates rapid and comprehensive characterization of nanoelectronic surfaces.
{"title":"On the Edge: In situ Kelvin probe AFM on InP nanowire arrays","authors":"Austin Irish , Lukas Hrachowina , David Alcer , Magnus Borgström , Rainer Timm","doi":"10.1016/j.ultramic.2025.114284","DOIUrl":"10.1016/j.ultramic.2025.114284","url":null,"abstract":"<div><div>Surface physics play an outsized role in nanostructured electronic devices such as solar cells. Semiconductor nanowires are perfect candidates for advanced solar cells due to their outstanding light absorption properties and their flexibility in axially stacking materials of different doping and band gap. Due to nanowire geometry, however, their surfaces dominate device performance and at the same time are challenging to investigate. Kelvin probe force microscopy (KPFM), an atomic force microscopy (AFM)-based method, provides a unique structural and electrical characterization even in unconventional 3D geometries. We demonstrate a high-resolution, non-destructive AFM technique for directly measuring nanowires within an array and still on their growth substrate. This <em>in situ</em> approach ensures measurement integrity and relevance while preserving the structures for subsequent measurement and processing. When compared with electron beam-induced current, cross-sectional KPFM is both more surface sensitive and less destructive. Utilizing such a cross-sectional approach facilitates rapid and comprehensive characterization of nanoelectronic surfaces.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"281 ","pages":"Article 114284"},"PeriodicalIF":2.0,"publicationDate":"2025-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145678990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-24DOI: 10.1016/j.ultramic.2025.114283
Yang Liu , Hongsheng Shi , Siyuan Shen , Yuan Lu , Shuchen Zhang , Jingyi Yu , Yi Yu
Atomic-scale imaging of radiation-sensitive materials has been a challenge for both materials science and life science. While low-dose transmission electron microscopy (TEM) is particularly useful for minimizing the radiation damage, the noisy images with poor resolution make it extremely difficult for the purpose of fine structure analysis. Here, this work presents a phase retrieval method to achieve high-quality atomic-scale imaging of radiation-sensitive materials under low-dose TEM conditions. By integrating neural fields (NF) with traditional exit wave reconstruction (EWR), it is able to reveal atomic details from limited low-dose experimental data. Taking the radiation-sensitive organic–inorganic hybrid halide perovskite CHNHPbI (MAPbI) as an example, the EWR-NF method demonstrates superior performance in reconstructing the pristine atomic structure using as few as just three low-dose images, which is beyond the limits of conventional methods. In this manner, EWR-NF enables higher temporal resolution to reveal intermediate states during irradiation-induced decomposition. An example of stacking of MAPbI with its as-decomposed product is shown. EWR-NF offers a promising tool for atomic-level structure analysis of sensitive halide perovskites and understanding irradiation-induced structure changes, with implications for a wide range of applications in materials science and beyond.
{"title":"Neural field enhanced phase retrieval of atomic-scale structural dynamics in radiation sensitive materials","authors":"Yang Liu , Hongsheng Shi , Siyuan Shen , Yuan Lu , Shuchen Zhang , Jingyi Yu , Yi Yu","doi":"10.1016/j.ultramic.2025.114283","DOIUrl":"10.1016/j.ultramic.2025.114283","url":null,"abstract":"<div><div>Atomic-scale imaging of radiation-sensitive materials has been a challenge for both materials science and life science. While low-dose transmission electron microscopy (TEM) is particularly useful for minimizing the radiation damage, the noisy images with poor resolution make it extremely difficult for the purpose of fine structure analysis. Here, this work presents a phase retrieval method to achieve high-quality atomic-scale imaging of radiation-sensitive materials under low-dose TEM conditions. By integrating neural fields (NF) with traditional exit wave reconstruction (EWR), it is able to reveal atomic details from limited low-dose experimental data. Taking the radiation-sensitive organic–inorganic hybrid halide perovskite CH<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>NH<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>PbI<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> (MAPbI<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>) as an example, the EWR-NF method demonstrates superior performance in reconstructing the pristine atomic structure using as few as just three low-dose images, which is beyond the limits of conventional methods. In this manner, EWR-NF enables higher temporal resolution to reveal intermediate states during irradiation-induced decomposition. An example of stacking of MAPbI<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> with its as-decomposed product is shown. EWR-NF offers a promising tool for atomic-level structure analysis of sensitive halide perovskites and understanding irradiation-induced structure changes, with implications for a wide range of applications in materials science and beyond.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"280 ","pages":"Article 114283"},"PeriodicalIF":2.0,"publicationDate":"2025-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145615330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-11DOI: 10.1016/j.ultramic.2025.114278
Evgenii Vlasov, Wouter Heyvaert, Tom Stoops, Sandra Van Aert, Johan Verbeeck, Sara Bals
Secondary electron (SE) imaging offers a powerful complementary capabilities to conventional scanning transmission electron microscopy (STEM) by providing surface-sensitive, pseudo-3D topographic information. However, contrast interpretation of such images remains empirical due to complex interactions of emitted SE with the magnetic field in the objective field of TEM. Here, we propose an analytical physical model that takes into account the physics of SE emission and interaction of the emitted SEs with magnetic field. This enables more reliable image interpretation and potentially lay the foundation for novel 3D surface reconstruction algorithms.
{"title":"Secondary electron topographical contrast formation in scanning transmission electron microscopy","authors":"Evgenii Vlasov, Wouter Heyvaert, Tom Stoops, Sandra Van Aert, Johan Verbeeck, Sara Bals","doi":"10.1016/j.ultramic.2025.114278","DOIUrl":"10.1016/j.ultramic.2025.114278","url":null,"abstract":"<div><div>Secondary electron (SE) imaging offers a powerful complementary capabilities to conventional scanning transmission electron microscopy (STEM) by providing surface-sensitive, pseudo-3D topographic information. However, contrast interpretation of such images remains empirical due to complex interactions of emitted SE with the magnetic field in the objective field of TEM. Here, we propose an analytical physical model that takes into account the physics of SE emission and interaction of the emitted SEs with magnetic field. This enables more reliable image interpretation and potentially lay the foundation for novel 3D surface reconstruction algorithms.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"280 ","pages":"Article 114278"},"PeriodicalIF":2.0,"publicationDate":"2025-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145518035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-09DOI: 10.1016/j.ultramic.2025.114277
Yanli Li , Yichen Ping , Yue Wu , Yao Liu , Huibin Zhao , Li Han
Reflected and transmitted secondary electron images of Si3N4 window are obtained in scanning electron microscopy (SEM) by using SEM and scanning transmission electron microscopy (STEM) holders. The figure of Si3N4 window becomes distinguishable as the accelerating voltage increases. However, the brightness of Si3N4 window relative to the surroundings in images for SEM and STEM holders is completely opposite. It changes from dark to bright, which means the number of detected secondary electron increases. The difference of the two kinds of image is caused by the fact that secondary electrons emitted from the bottom surface can also be detected when using STEM holder. The images are consistent with Monte Carlo simulation results. Image figures are sensitive to accelerating voltages and sample thicknesses. Therefore, more characteristics of thin sample could be analyzed via combining the two kinds of image.
{"title":"Reflected and transmitted secondary electron images of thin Si3N4 window","authors":"Yanli Li , Yichen Ping , Yue Wu , Yao Liu , Huibin Zhao , Li Han","doi":"10.1016/j.ultramic.2025.114277","DOIUrl":"10.1016/j.ultramic.2025.114277","url":null,"abstract":"<div><div>Reflected and transmitted secondary electron images of Si<sub>3</sub>N<sub>4</sub> window are obtained in scanning electron microscopy (SEM) by using SEM and scanning transmission electron microscopy (STEM) holders. The figure of Si<sub>3</sub>N<sub>4</sub> window becomes distinguishable as the accelerating voltage increases. However, the brightness of Si<sub>3</sub>N<sub>4</sub> window relative to the surroundings in images for SEM and STEM holders is completely opposite. It changes from dark to bright, which means the number of detected secondary electron increases. The difference of the two kinds of image is caused by the fact that secondary electrons emitted from the bottom surface can also be detected when using STEM holder. The images are consistent with Monte Carlo simulation results. Image figures are sensitive to accelerating voltages and sample thicknesses. Therefore, more characteristics of thin sample could be analyzed via combining the two kinds of image.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"280 ","pages":"Article 114277"},"PeriodicalIF":2.0,"publicationDate":"2025-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145514278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-09DOI: 10.1016/j.ultramic.2025.114279
Yupeng Yin , Ruiqi Zhan , Yufeng Du , Chi Xu , Somei Ohnuki , Farong Wan , Wentuo Han
The electron threshold energy (Et) of a material is a critical parameter for anyone conducting research using transmission electron microscopy (TEM). For studies involving irradiation damage, the electron beam energy must exceed the material’s Et to enable in-situ electron irradiation experiments. In contrast, for researchers focused on microstructural characterization, it is essential to ensure that the beam energy remains below Et to avoid electron-beam-induced radiation damage, which could compromise the accuracy and reliability of the TEM analysis. This study revisits the commonly used formula for calculating Et, originally cited in the textbook by Williams and Carter, and identifies significant discrepancies when compared with experimental observations and the original formulation. A corrected formula is proposed and applied to compute Et values for 81 elements using their minimum displacement energies (Ed min). The results are presented in a periodic-table-based diagram, providing practical reference for selecting appropriate TEM accelerating voltages to either induce or avoid irradiation damage.
{"title":"Evaluation of electron threshold energy for predicting radiation damage in transmission electron microscopy","authors":"Yupeng Yin , Ruiqi Zhan , Yufeng Du , Chi Xu , Somei Ohnuki , Farong Wan , Wentuo Han","doi":"10.1016/j.ultramic.2025.114279","DOIUrl":"10.1016/j.ultramic.2025.114279","url":null,"abstract":"<div><div>The electron threshold energy (E<sub>t</sub>) of a material is a critical parameter for anyone conducting research using transmission electron microscopy (TEM). For studies involving irradiation damage, the electron beam energy must exceed the material’s E<sub>t</sub> to enable in-situ electron irradiation experiments. In contrast, for researchers focused on microstructural characterization, it is essential to ensure that the beam energy remains below E<sub>t</sub> to avoid electron-beam-induced radiation damage, which could compromise the accuracy and reliability of the TEM analysis. This study revisits the commonly used formula for calculating E<sub>t</sub>, originally cited in the textbook by Williams and Carter, and identifies significant discrepancies when compared with experimental observations and the original formulation. A corrected formula is proposed and applied to compute E<sub>t</sub> values for 81 elements using their minimum displacement energies (E<sub>d min</sub>). The results are presented in a periodic-table-based diagram, providing practical reference for selecting appropriate TEM accelerating voltages to either induce or avoid irradiation damage.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"280 ","pages":"Article 114279"},"PeriodicalIF":2.0,"publicationDate":"2025-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145514262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lorentz transmission electron microscopy (LTEM) is a powerful tool for high-resolution imaging of magnetic textures, including their dynamics under external stimuli and ultrafast nonequilibrium conditions. However, magnetic imaging is often hindered by non-magnetic diffraction contrast arising from inhomogeneous sample deformation or a non-parallel electron beam. In this study, we develop a precession LTEM system that can suppress diffraction contrast by changing the incident angle of the electron beam relative to the sample in a precessional manner. By comparing LTEM images acquired at different precession angles (), we show that diffraction contrast is significantly reduced with increasing . However, large values lead to an undesired broadening of the magnetic contrast, highlighting the importance of optimizing . Furthermore, defocus-dependent measurements reveal that magnetic contrast is particularly improved at small defocus values. These findings demonstrate the potential of precession LTEM as a powerful technique for studying magnetic dynamics.
{"title":"Development of precession Lorentz transmission electron microscopy","authors":"Shunsuke Hayashi , Dongxue Han , Hidenori Tsuji , Kyoko Ishizaka , Asuka Nakamura","doi":"10.1016/j.ultramic.2025.114276","DOIUrl":"10.1016/j.ultramic.2025.114276","url":null,"abstract":"<div><div>Lorentz transmission electron microscopy (LTEM) is a powerful tool for high-resolution imaging of magnetic textures, including their dynamics under external stimuli and ultrafast nonequilibrium conditions. However, magnetic imaging is often hindered by non-magnetic diffraction contrast arising from inhomogeneous sample deformation or a non-parallel electron beam. In this study, we develop a precession LTEM system that can suppress diffraction contrast by changing the incident angle of the electron beam relative to the sample in a precessional manner. By comparing LTEM images acquired at different precession angles (<span><math><mi>θ</mi></math></span>), we show that diffraction contrast is significantly reduced with increasing <span><math><mi>θ</mi></math></span>. However, large <span><math><mi>θ</mi></math></span> values lead to an undesired broadening of the magnetic contrast, highlighting the importance of optimizing <span><math><mi>θ</mi></math></span>. Furthermore, defocus-dependent measurements reveal that magnetic contrast is particularly improved at small defocus values. These findings demonstrate the potential of precession LTEM as a powerful technique for studying magnetic dynamics.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"280 ","pages":"Article 114276"},"PeriodicalIF":2.0,"publicationDate":"2025-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145518128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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