Ultramicroscopy最新文献_第8页

Direct observation of oxygen vacancy ordering evolution in cerium oxide at varying concentrations via high-resolution transmission electron microscopy 用高分辨率透射电镜直接观察不同浓度氧化铈中氧空位有序演化

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2025-03-15 DOI: 10.1016/j.ultramic.2025.114133

Yong Ding , Yuzi Liu , Yu Chen , Meilin Liu , Zhong Lin Wang

{"title":"Direct observation of oxygen vacancy ordering evolution in cerium oxide at varying concentrations via high-resolution transmission electron microscopy","authors":"Yong Ding , Yuzi Liu , Yu Chen , Meilin Liu , Zhong Lin Wang","doi":"10.1016/j.ultramic.2025.114133","DOIUrl":"10.1016/j.ultramic.2025.114133","url":null,"abstract":"<div><div>Under illumination by a 300 keV electron beam, oxygen vacancy ordering structures are induced within cerium oxide grains. Our high-resolution transmission electron microscopy (HRTEM) study, supported by image simulation, reveals the evolution of these structures as vacancy concentration increases. The observed fluorite-type superlattice structures are identified as CeO<sub>1.825</sub>, CeO<sub>1.75</sub>, Ce<sub>2</sub>O<sub>3</sub>, displaying a gradient in oxygen vacancy concentration moving away from the grain surface. Correspondingly, the structural sequence transitions from Ce<sub>2</sub>O<sub>3</sub> to CeO<sub>1.75</sub> and then to CeO<sub>1.825</sub>. Without the constraints of surrounding grains, fluorite-type Ce<sub>2</sub>O<sub>3</sub> nanocrystals show a preference for transformation into an A-type trigonal structure. Notably, at temperatures up to 200°C, only the perfect fluorite structure is observed. Structural models were validated through both [110] and [001] projections. Our findings further confirm lattice expansion associated with local oxygen vacancy enrichment, which can be compensated by the formation of stacking faults, where a {111} oxygen plane is lost at defect sites.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"272 ","pages":"Article 114133"},"PeriodicalIF":2.1,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143654834","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

Quantitative evaluation of local magnetic property using magnetic domain wall width measurement with tilt-scan averaged DPC STEM 倾斜扫描平均DPC STEM磁畴壁宽测量定量评价局部磁性能

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2025-03-15 DOI: 10.1016/j.ultramic.2025.114132

Yoshiki O. Murakami , Takehito Seki , Koudai Tabata , Yuichi Ikuhara , Naoya Shibata

{"title":"Quantitative evaluation of local magnetic property using magnetic domain wall width measurement with tilt-scan averaged DPC STEM","authors":"Yoshiki O. Murakami , Takehito Seki , Koudai Tabata , Yuichi Ikuhara , Naoya Shibata","doi":"10.1016/j.ultramic.2025.114132","DOIUrl":"10.1016/j.ultramic.2025.114132","url":null,"abstract":"<div><div>Identifying the one-to-one relationship between microstructures and magnetic properties is crucial for improving the coercivity of permanent magnets. Magnetic domain wall (DW) is an important local magnetic structure, whose width is closely related to the local magnetic properties of the magnets. Unfortunately, due to the limitations of conventional experimental methods, direct and precise measurements of nanoscale DW widths have been challenging. However, recent advancements in differential phase contrast scanning transmission electron microscopy (DPC STEM) have enabled direct imaging of magnetic field distribution down to atomic dimensions. In this study, the precise measurement of the DW width in Nd-Fe-B type magnets using high-resolution DPC images in a magnetic field-free environment was demonstrated. The change in DW width with respect to the change in the magnet's local composition was measured. Moreover, we can estimate local magnetic properties such as exchange stiffness and magnetocrystalline anisotropy from the DW width. Therefore, DPC STEM can be used to evaluate the local magnetic properties of magnets with complex microstructures.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"272 ","pages":"Article 114132"},"PeriodicalIF":2.1,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143697021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Dynamical diffraction effects of inhomogeneous strain fields investigated by scanning convergent electron beam diffraction and dark field electron holography 扫描会聚电子束衍射和暗场电子全息研究了非均匀应变场的动态衍射效应

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2025-03-06 DOI: 10.1016/j.ultramic.2025.114122

L. Niermann, T. Niermann, M. Lehmann

{"title":"Dynamical diffraction effects of inhomogeneous strain fields investigated by scanning convergent electron beam diffraction and dark field electron holography","authors":"L. Niermann, T. Niermann, M. Lehmann","doi":"10.1016/j.ultramic.2025.114122","DOIUrl":"10.1016/j.ultramic.2025.114122","url":null,"abstract":"<div><div>Many material properties can be tuned by strain fields within the specimen. Examples range from mechanical properties of alloy hardening to electro-optical properties like emission wavelengths in semiconductor heterostructure quantum wells. While several transmission electron microscopy techniques for the measurements of these strain fields exists, these techniques typically neglect strain variations along the electron beam or try to mitigate their effects. Here we investigated the effects of these strain inhomogeneities along the beam direction under dynamical diffraction conditions. We performed scanning convergent beam electron diffraction and tilt series of dark-field electron holography measurements on an inclined layer structure, which exhibits a known 3D strain field. These measurements are compared with numerical multi-beam calculations, which allows to identify the depth of the strain inhomogeneity from the measured data. However, we observed a ambiguity of diffracted intensities stemming from a strain inhomogeneity which is symmetric with respect to the specimens mid-plane. The phases of the diffracted beams do not exhibit this symmetry. Furthermore, we also investigate the influence of experimental parameters like defocus and specimen curvature as well as relaxation effects on the measurements. We anticipate that the reported systematical investigations will form a starting point for the use of dynamical diffraction effects for more thorough measurements of 3D strain fields.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"271 ","pages":"Article 114122"},"PeriodicalIF":2.1,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143580330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

aquaDenoising: AI-enhancement of in situ liquid phase STEM video for automated quantification of nanoparticles growth aquaDenoising：人工智能增强的原位液相STEM视频，用于纳米颗粒生长的自动定量

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2025-03-04 DOI: 10.1016/j.ultramic.2025.114121

Adrien Moncomble , Damien Alloyeau , Maxime Moreaud , Abdelali Khelfa , Guillaume Wang , Nathaly Ortiz-Peña , Hakim Amara , Riccardo Gatti , Romain Moreau , Christian Ricolleau , Jaysen Nelayah

{"title":"aquaDenoising: AI-enhancement of in situ liquid phase STEM video for automated quantification of nanoparticles growth","authors":"Adrien Moncomble , Damien Alloyeau , Maxime Moreaud , Abdelali Khelfa , Guillaume Wang , Nathaly Ortiz-Peña , Hakim Amara , Riccardo Gatti , Romain Moreau , Christian Ricolleau , Jaysen Nelayah","doi":"10.1016/j.ultramic.2025.114121","DOIUrl":"10.1016/j.ultramic.2025.114121","url":null,"abstract":"<div><div>Automatic processing and full analysis of <em>in situ</em> liquid phase scanning transmission electron microscopy (LP-STEM) acquisitions are yet to be achievable with available techniques. This is particularly true for the extraction of information related to the nucleation and growth of nanoparticles (NPs) in liquid as several parasitic processes degrade the signal of interest. These degradations hinder the use of classical or state-of-the-art techniques making the understanding of NPs formation difficult to access. In this context, we propose aquaDenoising, a novel simulation-based deep neural framework to address the challenges of denoising LP-STEM images and videos. Trained on synthetic pairs of clean and noisy images obtained from kinematic-model-based simulations, we show that our model is able to achieve a fifteen-fold improvement in the signal-to-noise ratio of videos of gold NPs growing in water. The enhanced data unleash unprecedented possibilities for automatic segmentation and extraction of structures at different scales, from assemblies of objects down to the individual NPs with the same precision as manual segmentation performed by experts, but with higher throughput. The present denoising method can be easily adapted to other nanomaterials imaged in liquid media. All the codes developed in the present work are open and freely available.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"271 ","pages":"Article 114121"},"PeriodicalIF":2.1,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143580329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Acquisition of object and temperature series in medium resolution off-axis electron holography with live drift correction 实时漂移校正中分辨率离轴电子全息成像中物体和温度序列的采集

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2025-03-04 DOI: 10.1016/j.ultramic.2025.114119

Thibaud Denneulin, Benjamin Zingsem, Joseph Vas, Wen Shi, Luyan Yang, Michael Feuerbacher, Rafal E. Dunin-Borkowski

{"title":"Acquisition of object and temperature series in medium resolution off-axis electron holography with live drift correction","authors":"Thibaud Denneulin, Benjamin Zingsem, Joseph Vas, Wen Shi, Luyan Yang, Michael Feuerbacher, Rafal E. Dunin-Borkowski","doi":"10.1016/j.ultramic.2025.114119","DOIUrl":"10.1016/j.ultramic.2025.114119","url":null,"abstract":"<div><div>Collecting and averaging large datasets is a common practice in transmission electron microscopy to improve the signal-to-noise ratio. Averaging data in off-axis electron holography requires automated tools capable of correcting both the drift of the interference fringes and the drift of the specimen. This can be achieved either off-line, by post-processing hologram series, or on-line, through real-time microscope control. For on-line correction, a previously suggested method involves independently adjusting the position of the intereference fringes and the sample by controlling the beam tilt coils and the stage during hologram acquisition. In this study, we have implemented this on-line correction method in a Thermo Fisher Scientific Titan transmission electron microscope. The microscope is equipped with a piezo-enhanced CompuStage for positioning the sample with high precision. However, the control of the piezo stage via direct scripting is not supported. We first describe a workaround to enable automated sample position correction. We then demonstrate the benefits of live, program-controlled acquisitions for serial experiments in medium resolution off-axis electron holography. Application examples include the automatic acquisition of an object series such as a transistor array and an <em>in-situ</em> temperature series of magnetic skyrmions.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"271 ","pages":"Article 114119"},"PeriodicalIF":2.1,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143593126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Negative stain TEM imaging of native spider silk protein superstructures 原生蜘蛛丝蛋白上层结构的透射电镜负染色成像

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2025-02-27 DOI: 10.1016/j.ultramic.2025.114124

Hannah R. Johnson, Legend Foster, Anikin Rae Domingo, Gregory P. Holland

引用次数: 0

Quantifying elemental colocation in nanostructured materials using energy-dispersive X-ray spectroscopy 利用能量色散x射线光谱定量纳米结构材料中的元素共配

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2025-02-26 DOI: 10.1016/j.ultramic.2025.114123

Kristiaan H. Helfferich , Johannes D. Meeldijk , Marijn A. van Huis , Jessi E.S. van der Hoeven , Petra E. de Jongh

{"title":"Quantifying elemental colocation in nanostructured materials using energy-dispersive X-ray spectroscopy","authors":"Kristiaan H. Helfferich , Johannes D. Meeldijk , Marijn A. van Huis , Jessi E.S. van der Hoeven , Petra E. de Jongh","doi":"10.1016/j.ultramic.2025.114123","DOIUrl":"10.1016/j.ultramic.2025.114123","url":null,"abstract":"<div><div>Multicomponent nanostructured materials are key amongst others for energy and catalysis applications. The nanoscale proximity of different metals critically determines the performance of these functional materials. However, it is difficult to study the spatial distribution of different elements at the nanoscale, especially achieving a statistically relevant assessment. Additionally, common support materials like metal oxides are sensitive to electron beam damage when using high resolution local techniques, such as transmission electron microscopy. We present a robust strategy to quantitatively assess elemental distributions in 3D nanostructured beam-sensitive samples. Key elements are resin embedding, and elemental co-localisation building on a combination of electron tomography and energy-dispersive X-ray spectroscopy. We showcase the methodology with ∼ 3 nm Pd-Ni nanoparticles supported on mesoporous silica. Epoxy resin-embedding ensured sufficient sample stability under the electron beam for tomography-based quantification of different mano- and mesoscale elemental distributions in these samples. Reliable co-location results were obtained and practical guidelines are provided for acquisition and post-processing, relevant for elemental overlap analysis in multi-metallic samples.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"271 ","pages":"Article 114123"},"PeriodicalIF":2.1,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143520927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Using non-parametric statistical testing to quantify solute clustering in atom probe reconstructions 用非参数统计检验量化原子探针重构中溶质聚类

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2025-02-24 DOI: 10.1016/j.ultramic.2025.114120

William J. Davids, Mengwei He, Huma Bilal, Andrew J. Breen, Simon P. Ringer

引用次数: 0

Commonsense and common nonsense opinions: PROSPECTS for further reducing beam damage in electron microscopy of radiation-sensitive specimens 常识性与谬论性观点：进一步降低辐射敏感样品电子显微镜束损伤的前景

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2025-02-16 DOI: 10.1016/j.ultramic.2025.114118

Robert M. Glaeser

引用次数: 0

A versatile machine learning workflow for high-throughput analysis of supported metal catalyst particles 一个通用的机器学习工作流程，用于高通量分析负载金属催化剂颗粒

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2025-02-16 DOI: 10.1016/j.ultramic.2025.114116

Arda Genc , Justin Marlowe , Anika Jalil , Daniel Belzberg , Libor Kovarik , Phillip Christopher

{"title":"A versatile machine learning workflow for high-throughput analysis of supported metal catalyst particles","authors":"Arda Genc , Justin Marlowe , Anika Jalil , Daniel Belzberg , Libor Kovarik , Phillip Christopher","doi":"10.1016/j.ultramic.2025.114116","DOIUrl":"10.1016/j.ultramic.2025.114116","url":null,"abstract":"<div><div>Accurate and efficient characterization of nanoparticles (NPs), particularly regarding particle size distribution, is essential for advancing our understanding of their structure-property relationship and facilitating their design for various applications. In this study, we introduce a novel two-stage artificial intelligence (AI)-driven workflow for NP analysis that leverages prompt engineering techniques from state-of-the-art single-stage object detection and large-scale vision transformer (ViT) architectures. This methodology is applied to transmission electron microscopy (TEM) and scanning TEM (STEM) images of heterogeneous catalysts, enabling high-resolution, high-throughput analysis of particle size distributions for supported metal catalyst NPs. The model's performance in detecting and segmenting NPs is validated across diverse heterogeneous catalyst systems, including various metals (Ru, Cu, PtCo, and Pt), supports (silica (SiO<sub>2</sub>), γ-alumina (γ-Al<sub>2</sub>O<sub>3</sub>), and carbon black), and particle diameter size distributions with mean and standard deviations ranging from 1.6 ± 0.2 nm to 9.7 ± 4.6 nm. The proposed machine learning (ML) methodology achieved an average F1 overlap score of 0.91 ± 0.01 and demonstrated the ability to disentangle overlapping NPs anchored on catalytic support materials. The segmentation accuracy is further validated using the Hausdorff distance and robust Hausdorff distance metrics, with the 90th percent of the robust Hausdorff distance showing errors within 0.4 ± 0.1 nm to 1.4 ± 0.6 nm. Our AI-assisted NP analysis workflow demonstrates robust generalization across diverse datasets and can be readily applied to similar NP segmentation tasks without requiring costly model retraining.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"271 ","pages":"Article 114116"},"PeriodicalIF":2.1,"publicationDate":"2025-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143509280","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