Ultramicroscopy最新文献_第6页

Quantitative magnetic mapping in TEM through accurate 2D thickness determination 通过精确的二维厚度测定，在TEM中进行定量磁成像

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2025-05-09 DOI: 10.1016/j.ultramic.2025.114140

Joseph Vimal Vas , Hasan Ali , Wen Shi , Thibaud Denneulin , Ayush K Gupta , Rohit Medwal , Rafal E. Dunin-Borkowski

{"title":"Quantitative magnetic mapping in TEM through accurate 2D thickness determination","authors":"Joseph Vimal Vas , Hasan Ali , Wen Shi , Thibaud Denneulin , Ayush K Gupta , Rohit Medwal , Rafal E. Dunin-Borkowski","doi":"10.1016/j.ultramic.2025.114140","DOIUrl":"10.1016/j.ultramic.2025.114140","url":null,"abstract":"<div><div>Off-axis Electron Holography and Electron Magnetic Circular Dichroism are powerful Transmission Electron Microscopy (TEM) techniques capable of mapping magnetic information with near-atomic spatial resolution. However, the magnetic signals obtained is semi-quantitative due to factors such as thickness variations and local crystallographic changes. Precise determination of spatial thickness variations can make these techniques more quantitative. Electron Energy Loss Spectroscopy (EELS) provides a method to measure thickness variations within a region of interest. The absolute thickness depends on reliable estimates of the inelastic mean free path (<span><math><mi>λ</mi></math></span>), which is often unknown for many materials. Alternative techniques, such as Scanning Electron Microscopy (SEM) and Convergent Beam Electron Diffraction (CBED), either lack spatial resolution in thickness mapping or are accurate only within a limited thickness range. Here, we present a straightforward approach to precisely determine the inelastic mean free path (<span><math><mi>λ</mi></math></span>), enabling accurate thickness measurements from EELS maps. We compare these thickness measurements with CBED- and SEM-based methods, identifying discrepancies, particularly in thinner samples (<span><math><mrow><mo><</mo><mn>100</mn><mspace></mspace><mi>nm</mi></mrow></math></span>). Finally, we demonstrate how this calibrated thickness measurement can provide quantitative magnetic maps using TEM-based magnetic measurements.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"275 ","pages":"Article 114140"},"PeriodicalIF":2.1,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144069971","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}

引用次数: 0

An improved soft-thresholding exit wave reconstruction for imaging beam-sensitive materials 一种用于光束敏感材料成像的改进软阈值出口波重建方法

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2025-05-04 DOI: 10.1016/j.ultramic.2025.114154

Hongsheng Shi , Yuan Lu , Zeyu Wang , Shuchen Zhang , Yi Yu

{"title":"An improved soft-thresholding exit wave reconstruction for imaging beam-sensitive materials","authors":"Hongsheng Shi , Yuan Lu , Zeyu Wang , Shuchen Zhang , Yi Yu","doi":"10.1016/j.ultramic.2025.114154","DOIUrl":"10.1016/j.ultramic.2025.114154","url":null,"abstract":"<div><div>High-resolution transmission electron microscopy (HRTEM) is a widely-used technique for atomic-scale characterization. However, the conventional dose of HRTEM can destroy beam-sensitive materials such as organic-inorganic halide perovskites. CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub> (MAPbI<sub>3</sub>), a typical perovskite, will be easily damaged after irradiated with the dose of ∼10<sup>2</sup> e-/Å<sup>2</sup>. Low-dose imaging techniques can protect the specimen but it is difficult to achieve an image which is both directly interpreted and atomically clear. Exit wave reconstruction (EWR), as one of phase retrieval methods, can recover an interpretable phase image at the atomic scale but its signal-to-noise ratio (SNR) is limited by low electron doses. Here, we improve the iterative wave function reconstruction (IWFR) method and present a soft-thresholding L<sub>1</sub>-IWFR. Results from both simulated and experimental focal-series dataset at the extremely low dose show that L<sub>1</sub>-IWFR improves the SNR effectively and has better performance on low-dose datasets than IWFR. Combined with low-dose imaging techniques and various alignment strategies, an atomically clear image of CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub> (MAPbI<sub>3</sub>) is successfully achieved at the total dose of ∼45 e<sup>-</sup>/Å<sup>2</sup>.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"274 ","pages":"Article 114154"},"PeriodicalIF":2.1,"publicationDate":"2025-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143928576","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}

引用次数: 0

Compact design, construction, and evaluation of an in situ ±90° rotatable magnetic force microscope in a 12 T superconducting magnet 在12 T超导磁体上的原位±90°可旋转磁力显微镜的紧凑设计，构建和评估

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2025-05-03 DOI: 10.1016/j.ultramic.2025.114155

Min Zhang , Shuai Dong , Zihao Li , Kesen Zhao , Aile Wang , Wenjie Meng , Qiyuan Feng , Jing Zhang , Jihao Wang , Yalin Lu , Yubin Hou , Qingyou Lu

{"title":"Compact design, construction, and evaluation of an in situ ±90° rotatable magnetic force microscope in a 12 T superconducting magnet","authors":"Min Zhang , Shuai Dong , Zihao Li , Kesen Zhao , Aile Wang , Wenjie Meng , Qiyuan Feng , Jing Zhang , Jihao Wang , Yalin Lu , Yubin Hou , Qingyou Lu","doi":"10.1016/j.ultramic.2025.114155","DOIUrl":"10.1016/j.ultramic.2025.114155","url":null,"abstract":"<div><div>Cryogenic magnetic force microscopy (MFM) is a powerful technique capable of resolving exotic magnetic textures with nanoscale resolution in real-space. We introduce a cryogenic rotatable MFM (CRMFM) that enables the visualization of in situ evolution of magnetic domains by rotating magnetic samples between −90° and +90° within a 12 T superconducting magnet. By continuously rotating the sample under an external magnetic field, the direction of the magnetic field can be varied from out-of-plane to in-plane, enabling microscopic analysis experiments that require vector magnetic fields within the CRMFM system. By using CRMFM measurements, we successfully transformed long magnetic stripe domains into isolated magnetic bubble domains and proposed a novel strategy for visualizing stripe-bubble transitions in magnetic domains. Additionally, we demonstrated that the CRMFM system can generate high-quality MFM images under in-plane magnetic fields up to 12 T. Our research provides a framework for visualizing the interaction between ferromagnetism and magnetic field direction, facilitating the study of magnetic crystal anisotropy.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"274 ","pages":"Article 114155"},"PeriodicalIF":2.1,"publicationDate":"2025-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143931517","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}

引用次数: 0

High-precision atomic imaging using an innovative vibration-isolated scanning tunneling microscope 使用创新的隔振扫描隧道显微镜进行高精度原子成像

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2025-05-03 DOI: 10.1016/j.ultramic.2025.114157

Behnam Esmaeilzadeh , Muhammad Touqeer , Syed Asad Maqbool , Jihao Wang , Wenjie Meng , Yubin Hou , Yalin Lu , Qingyou Lu

{"title":"High-precision atomic imaging using an innovative vibration-isolated scanning tunneling microscope","authors":"Behnam Esmaeilzadeh , Muhammad Touqeer , Syed Asad Maqbool , Jihao Wang , Wenjie Meng , Yubin Hou , Yalin Lu , Qingyou Lu","doi":"10.1016/j.ultramic.2025.114157","DOIUrl":"10.1016/j.ultramic.2025.114157","url":null,"abstract":"<div><div>The stability of the scanning unit in a scanning tunneling microscope (STM) is essential for achieving high-resolution imaging. In this study, we present a non-metallic STM with a mechanically isolated scanning unit, ensuring long-term drift stability, low backlash, and high repeatability. By decoupling the piezoelectric scanning tube (PST) from the piezoelectric motor tube (PMT), the design effectively minimizes motor-induced instabilities and vibrations, significantly improving STM performance. The use of non-metallic materials for key components prevents eddy current interference and ensures long-term reliability. A sapphire-based frame provides high stiffness and compactness, with an eigenfrequency of 16.2 kHz in bending mode, reducing vibration noise during atomic imaging. The system exhibits excellent stability, maintaining low drift rates in both the X-Y plane and Z direction, ensuring precise tip-sample alignment. The performance of the home-built STM was validated through high-resolution atomic imaging of graphite and TaS<sub>2</sub> surfaces. The simple, compact, and high-precision stepping mechanism, along with its ability to operate at low voltage, reduces experimental complexity. These features facilitate advanced material studies in constrained environments, such as high magnetic fields and low temperatures.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"274 ","pages":"Article 114157"},"PeriodicalIF":2.1,"publicationDate":"2025-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143924223","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}

引用次数: 0

Prediction of the morphology of nano particles based solely on atom counting data 仅基于原子计数数据的纳米粒子形态预测

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2025-05-02 DOI: 10.1016/j.ultramic.2025.114139

Ivo Alxneit

{"title":"Prediction of the morphology of nano particles based solely on atom counting data","authors":"Ivo Alxneit","doi":"10.1016/j.ultramic.2025.114139","DOIUrl":"10.1016/j.ultramic.2025.114139","url":null,"abstract":"<div><div>The framework to determine the morphology of nano particles from atomically resolved electron microscopy images and atom counting data is introduced. Focus is placed on electron microscopy data avoiding advanced geometry optimization of the particle. The problem is solved by simulated annealing with different fitness functions assessed. Even for small particles the solution space rapidly becomes too large to be exhausted. The concept of site occupation probabilities, <span><math><msub><mrow><mi>p</mi></mrow><mrow><mi>i</mi></mrow></msub></math></span>, is then used to analyze a subset, typically very few hundred solutions. This is shown to be sufficient to reach a relative error of below 10% for <span><math><mrow><msub><mrow><mi>p</mi></mrow><mrow><mi>i</mi></mrow></msub><mo>></mo><mn>0</mn><mo>.</mo><mn>5</mn></mrow></math></span> already with 100 solutions allowing to determine with high confidence and low statistical error realistic average shapes also for nano particles of a few thousand atoms. These particles typically exhibit a well defined core covered by a layer of sites that are not occupied in each solution. It is further demonstrated that sites with high probability to contain a vacancy can be identified <em>assuming</em> the presence of a vacancy. If a vacancy is actually present in a particle its position can be identified with rather high fidelity. Finally, it is shown that the procedure can cope with the statistical error or ambiguities inherent in atom counting data based on noisy, low dose electron microscopy images.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"275 ","pages":"Article 114139"},"PeriodicalIF":2.1,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144123527","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}

引用次数: 0

Robust projection parameter calibration in cryo-ET with L1-norm optimization 基于l1范数优化的cryo-ET鲁棒投影参数标定

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2025-04-29 DOI: 10.1016/j.ultramic.2025.114134

Shengkai Guo , Zihe Xu , Xinyan Li , Zhidong Yang , Chenjie Feng , Renmin Han

{"title":"Robust projection parameter calibration in cryo-ET with L1-norm optimization","authors":"Shengkai Guo , Zihe Xu , Xinyan Li , Zhidong Yang , Chenjie Feng , Renmin Han","doi":"10.1016/j.ultramic.2025.114134","DOIUrl":"10.1016/j.ultramic.2025.114134","url":null,"abstract":"<div><div>Fiducial marker-based alignment in cryo-electron tomography (cryo-ET) has been extensively studied over a long period. The calibration of projection parameters using nonlinear least squares technique methodologies stands as the ultimate and pivotal stage in the alignment procedure. The efficacy of calibration is substantially impacted by noise and outliers in the marker data obtained from previous steps. Several robust fitting methods have been explored and implemented to address this issue by improving marker data or assigning weights to markers. However, these methods have their own limitations and often assume general Gaussian noise assumption, which may not accurately represent the distribution of noise and outliers in the marker data. In this work, we propose a robust projection parameter calibration model based on <span><math><msub><mrow><mi>L</mi></mrow><mrow><mn>1</mn></mrow></msub></math></span>-norm optimization under Laplace noise assumption in order to overcome the limitations of existing methods. To efficiently solve the problem, we also design a faster and stabler first-order non-sparse method based on smooth approximation strategy. Additionally, we introduce subgradient and subdifferential for mathematical analysis. The accuracy, robustness, and efficacy of our approach are demonstrated through both simulated and real-world experiments.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"274 ","pages":"Article 114134"},"PeriodicalIF":2.1,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143907639","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}

引用次数: 0

On the impulse approximation in electron Compton scattering 电子康普顿散射中的脉冲近似

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2025-04-26 DOI: 10.1016/j.ultramic.2025.114153

BG Mendis

引用次数: 0

Opportunities and challenges to determine surface free energy of chocolates on microscopic scale from atomic force microscopy adhesion measurements 原子力显微镜黏附测量在微观尺度上测定巧克力表面自由能的机遇与挑战

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2025-04-18 DOI: 10.1016/j.ultramic.2025.114150

Sarah Schroeder , Koen Dewettinck , Volker Heinz , Ute Bindrich , Dana Middendorf , Knut Franke

{"title":"Opportunities and challenges to determine surface free energy of chocolates on microscopic scale from atomic force microscopy adhesion measurements","authors":"Sarah Schroeder , Koen Dewettinck , Volker Heinz , Ute Bindrich , Dana Middendorf , Knut Franke","doi":"10.1016/j.ultramic.2025.114150","DOIUrl":"10.1016/j.ultramic.2025.114150","url":null,"abstract":"<div><div>Surface free energy (SFE) is an important surface property in food processing as it determines the wettability of solid surfaces or the interaction of mould surfaces and chocolate during the moulding process. High-resolution information about SFE could be useful to understand gloss inhomogeneities of chocolates after de-moulding. SFE is connected with adhesion properties. Thus, Atomic force microscopy (AFM) adhesion measurements can be applied to determine SFE of a solid surface at microscopic scale. For this purpose, AFM tips were functionalized to modify their SFE and used for adhesion measurements at three different chocolate gloss areas (matt, glossy and homogenous) via AFM force maps. Influence of relevant parameters such as surface roughness, contact area, relative humidity, and SFE of functionalized tips was considered. Two different mathematical approaches based on Johnson-Kendall-Roberts theory were used to calculate SFE from adhesion values. The measured adhesion values showed variations depending on functionalized tip and chocolate gloss area. The results showed a difference in adhesion and, consequently, SFE in the different gloss areas with gloss > homogenous > matt. However, SFE obtained from adhesion forces were not decisive enough to enable a direct correlation with SFE data from contact angle measurements at the same area.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"273 ","pages":"Article 114150"},"PeriodicalIF":2.1,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143855695","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}

引用次数: 0

Influence of experimental conditions on apparent AFM tip-surface contact in air 空气中实验条件对AFM尖端表面表观接触的影响

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2025-04-18 DOI: 10.1016/j.ultramic.2025.114148

Ilya A. Morozov, Roman I. Izyumov

{"title":"Influence of experimental conditions on apparent AFM tip-surface contact in air","authors":"Ilya A. Morozov, Roman I. Izyumov","doi":"10.1016/j.ultramic.2025.114148","DOIUrl":"10.1016/j.ultramic.2025.114148","url":null,"abstract":"<div><div>Accurate determination of the onset of the contact between the atomic force microscope (AFM) tip and the surface in force measurements is necessary both for calculating the constants of non-contact interactions and for determining the structural and mechanical properties of the materials. In an air environment the contact is preceded by a rapid jump of the tip to the surface due to attractive forces. If a surface is not deformed by a probe of a given stiffness, the end of the jump (minimum of the deflection of the cantilever) is taken as the onset of the contact. In this work, it is shown that the tip contacts with the deformable surface before the completion of the jump. It is reasonable to use the point of the extreme deflection velocity as the onset of the contact. A dynamic mass-spring model of the interaction of the tip with the viscoelastic material has shown that the high deflection velocity and the low rate of data acquisition (bandwidth) are the reasons for significant errors in determining the contact from the experimental force curve. In the most cases, the observed contact point is lower than the actual one (under certain conditions, the opposite situation is also possible) and the measurement error is at least 50 % (depending on the experimental settings, the properties of the probe and the material).</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"273 ","pages":"Article 114148"},"PeriodicalIF":2.1,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143870563","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}

引用次数: 0

Capacitance compensation on a double-barrel nanopipette for improving current detection of scanning ion conductance microscopy 双管纳米吸管的电容补偿提高扫描离子电导显微镜的电流检测

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2025-04-18 DOI: 10.1016/j.ultramic.2025.114149

Futoshi Iwata , Naoto Fukuzawa , Hitoshi Inomata , Kenta Nakazawa , Toshi Nagata , Hideya Kawasaki , Osamu Hoshi

{"title":"Capacitance compensation on a double-barrel nanopipette for improving current detection of scanning ion conductance microscopy","authors":"Futoshi Iwata , Naoto Fukuzawa , Hitoshi Inomata , Kenta Nakazawa , Toshi Nagata , Hideya Kawasaki , Osamu Hoshi","doi":"10.1016/j.ultramic.2025.114149","DOIUrl":"10.1016/j.ultramic.2025.114149","url":null,"abstract":"<div><div>We developed a method to improve the current-detection response of scanning ion conduction microscopy (SICM) using a double-barrel nanopipette. By detecting the difference between the two signals from each channel, capacitive currents can be canceled out, resulting in an improved ion current detection response and reduced imaging time in bias-modulated scanning ion conductance microscopy operated with AC bias voltages (BM-SICM). Furthermore, this method can reduce the synchronized capacitive current noise of two adjacent channels of a double-barrel nanopipette by canceling each other via a differential operation. Therefore, an improved detection signal was achieved even in the SICM operated with a DC bias voltage by reducing the noise from the piezoelectric scanner. As demonstrated by the proposed method, chromosomes that were difficult to observe owing to their strong negative charges were clearly imaged in the BM-SICM operated with an AC bias voltage without artifacts caused by surface charging. Additionally, in SICM operating with a DC bias voltage, dynamic interaction among an intracellular short rod, <em>Listeria monocytogenes</em>, and Caco-2 human enterocyte-like cells was successfully observed.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"273 ","pages":"Article 114149"},"PeriodicalIF":2.1,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143864533","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}

引用次数: 0