Ultramicroscopy最新文献_第9页

An applied noise model for low-loss EELS maps 低损耗EELS地图的应用噪声模型。

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2025-01-13 DOI: 10.1016/j.ultramic.2024.114101

Christian Zietlow, Jörg K.N. Lindner

{"title":"An applied noise model for low-loss EELS maps","authors":"Christian Zietlow, Jörg K.N. Lindner","doi":"10.1016/j.ultramic.2024.114101","DOIUrl":"10.1016/j.ultramic.2024.114101","url":null,"abstract":"<div><div>Electron energy-loss spectroscopy (EELS) performed in a scanning transmission electron microscope (STEM) is susceptible to noise, just like every other measurement. EELS measurements are also affected by signal blurring, related to the energy distribution of the electron beam and the detector point spread function (PSF). Moreover, the signal blurring caused by the detector introduces correlation effects, which smooth the noise. A general understanding of the noise is essential for evaluating the quality of measurements or for designing more effective post-processing techniques such as deconvolution, which especially in the context of EELS is a common practice to enhance signals. Therefore, we offer theoretical insight into the noise smoothing by convolution and characterize the resulting noise correlations by Pearson coefficients. Additional effects play a role in EELS mapping, where multiple spectra are acquired sequentially at various specimen positions. These three-dimensional datasets are affected by energy drifts of the electron beam, causing spectra to shift relative to each other, and by beam current deviations, which alter their relative proportion. We investigate several energy alignment techniques to correct energy drifts on a sub-channel level and describe the intensity normalization necessary to correct for beam current deviations. Both procedures affect noises and uncertainties of the measurement to various degrees. In this paper, we mathematically derive an applied noise model for EELS measurements, which is straightforward to use. Therefore, we provide the necessary methods to determine the most important noise parameters of the EELS detector enabling users to adapt the model. In summary, we aim to provide a comprehensive understanding of the noises faced in EELS and offer the necessary tools to apply this knowledge in practice.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"270 ","pages":"Article 114101"},"PeriodicalIF":2.1,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143012394","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

Improving the accuracy of temperature measurement on TEM samples using plasmon energy expansion thermometry (PEET): Addressing sample thickness effects 利用等离子体能量膨胀测温仪（PEET）提高TEM样品温度测量的准确性：解决样品厚度效应。

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2025-01-04 DOI: 10.1016/j.ultramic.2025.114102

Yi-Chieh Yang , Luca Serafini , Nicolas Gauquelin , Johan Verbeeck , Joerg R. Jinschek

{"title":"Improving the accuracy of temperature measurement on TEM samples using plasmon energy expansion thermometry (PEET): Addressing sample thickness effects","authors":"Yi-Chieh Yang , Luca Serafini , Nicolas Gauquelin , Johan Verbeeck , Joerg R. Jinschek","doi":"10.1016/j.ultramic.2025.114102","DOIUrl":"10.1016/j.ultramic.2025.114102","url":null,"abstract":"<div><div>Advances in analytical scanning transmission electron microscopy (STEM) and in microelectronic mechanical systems (MEMS) based microheaters have enabled <em>in-situ</em> materials’ characterization at the nanometer scale at elevated temperature. In addition to resolving the structural information at elevated temperatures, detailed knowledge of the local temperature distribution inside the sample is essential to reveal thermally induced phenomena and processes. Here, we investigate the accuracy of plasmon energy expansion thermometry (PEET) as a method to map the local temperature in a tungsten (W) lamella in a range between room temperature and 700 °C. In particular, we address the influence of sample thickness in the range of a typical electron-transparent TEM sample (from 30 nm to 70 nm) on the temperature-dependent plasmon energy. The shift in plasmon energy, used to determine the local sample temperature, is not only temperature-dependent, but in case of W also seems thickness-dependent in sample thicknesses below approximately 60 nm. It is believed that the underlying reason is the high susceptibility of the regions with thinner sample thickness to strain from residual load induced during FIB deposition, together with increased thermal expansion in these areas due to their higher surface-to-volume ratio. The results highlight the importance of considering sample thickness (and especially thickness variations) when analyzing the local bulk plasmon energy for temperature measurement using PEET. However, in case of W, an increasing beam broadening (FWHM) of the bulk plasmon peak with decreasing sample thickness can be used to improve the accuracy of PEET in TEM lamellae with varying sample thickness.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"270 ","pages":"Article 114102"},"PeriodicalIF":2.1,"publicationDate":"2025-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143012407","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

State-of-the-art electron beams for compact tools of ultrafast science 最先进的电子束用于超快科学的紧凑工具。

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2025-01-01 DOI: 10.1016/j.ultramic.2024.114080

Peter Salén , Anatoliy Opanasenko , Giovanni Perosa , Vitaliy Goryashko

引用次数: 0

Enhancing subsurface imaging in ultrasonic atomic force microscopy with optimized contact force 优化接触力增强超声原子力显微镜的亚表面成像。

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2024-12-08 DOI: 10.1016/j.ultramic.2024.114094

Mingyu Duan , Chengjian Wu , Jinyan Tang , Yuyang Wang , Shiquan Liu , Bing-Feng Ju , Yuan-Liu Chen

{"title":"Enhancing subsurface imaging in ultrasonic atomic force microscopy with optimized contact force","authors":"Mingyu Duan , Chengjian Wu , Jinyan Tang , Yuyang Wang , Shiquan Liu , Bing-Feng Ju , Yuan-Liu Chen","doi":"10.1016/j.ultramic.2024.114094","DOIUrl":"10.1016/j.ultramic.2024.114094","url":null,"abstract":"<div><div>Ultrasonic atomic force microscopy (UAFM) is a powerful nondestructive subsurface imaging tool that is widely used to inspect material defects and analyze biological cells. The contrast in UAFM images, which is crucial for subsurface imaging quality, is directly influenced by the contact force between the probe and material. This contact force affects the subsurface contrast by influencing the propagation of the stress field from the vibrating probe into the material. Therefore, optimizing the contact force is essential for achieving superior subsurface contrast with better resolution and greater detectable depth. This paper proposes a model for determining the optimal contact force for high-contrast, high-resolution subsurface imaging. The model was designed to improve UAFM imaging across samples with a wide range of Young's moduli, from tens to hundreds of GPa. The use of this model resulted in significant improvements to imaging quality, with a detectable depth exceeding 337.7 nm and lateral resolution below 56.9 nm. Hence, this model demonstrates better results than experiments conducted under arbitrary contact forces. This study provides a pathway for optimizing subsurface imaging and delivering enhanced contrast, higher resolution, and greater detectable depth. Consequently, the results of this study contribute to the advancement of the capabilities of subsurface imaging techniques.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"269 ","pages":"Article 114094"},"PeriodicalIF":2.1,"publicationDate":"2024-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142824516","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

Workflow automation of SEM acquisitions and feature tracking SEM获取和特征跟踪的工作流自动化。

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2024-12-08 DOI: 10.1016/j.ultramic.2024.114093

Sabrina Clusiau , Nicolas Piché , Nicolas Brodusch , Mike Strauss , Raynald Gauvin

{"title":"Workflow automation of SEM acquisitions and feature tracking","authors":"Sabrina Clusiau , Nicolas Piché , Nicolas Brodusch , Mike Strauss , Raynald Gauvin","doi":"10.1016/j.ultramic.2024.114093","DOIUrl":"10.1016/j.ultramic.2024.114093","url":null,"abstract":"<div><div>Acquiring multiple high magnification, high resolution images with scanning electron microscopes (SEMs) for quantitative analysis is a time consuming and repetitive task for microscopists. We propose a workflow to automate SEM image acquisition and demonstrate its use in the context of nanoparticle (NP) analysis. Acquiring multiple images of this type of specimen is necessary to obtain a complete and proper characterization of the NP population and obtain statistically representative results. Indeed, a single high magnification image only scans a small area of sample, containing only few NPs. The proposed workflow is successfully applied to obtain size distributions from image montages at three different magnifications (20,000x, 60,000x and 200,000x) on the same area of the sample using a Python based script. The automated workflow consists of sequential repositioning of the electron beam, stitching of adjacent images, feature segmentation, and NP size computation. Results show that NPs are best characterized at higher magnifications, since lower magnifications are limited by their pixel size. Increased accuracy of feature characterization at high magnification highlights the importance of automation: many high-magnification acquisitions are required to cover a similar area of the sample at low magnification. Therefore, we also present feature tracking with smart beam positioning as an alternative to blind acquisition of very large image arrays. Feature tracking is achieved by integrating microscope tasks with image processing tasks, and only areas of interest will be imaged at high resolution, reducing total acquisition duration.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"269 ","pages":"Article 114093"},"PeriodicalIF":2.1,"publicationDate":"2024-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142819184","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

Improved precision and accuracy of electron energy-loss spectroscopy quantification via fine structure fitting with constrained optimization 基于约束优化的精细结构拟合提高了电子能量损失谱定量的精密度和准确度。

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2024-12-05 DOI: 10.1016/j.ultramic.2024.114084

Daen Jannis , Wouter Van den Broek , Zezhong Zhang , Sandra Van Aert , Jo Verbeeck

引用次数: 0

Relativistic EELS scattering cross-sections for microanalysis based on Dirac solutions 基于Dirac解的相对论EELS微分析散射截面。

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2024-12-02 DOI: 10.1016/j.ultramic.2024.114083

Zezhong Zhang , Ivan Lobato , Hamish Brown , Dirk Lamoen , Daen Jannis , Johan Verbeeck , Sandra Van Aert , Peter D. Nellist

{"title":"Relativistic EELS scattering cross-sections for microanalysis based on Dirac solutions","authors":"Zezhong Zhang , Ivan Lobato , Hamish Brown , Dirk Lamoen , Daen Jannis , Johan Verbeeck , Sandra Van Aert , Peter D. Nellist","doi":"10.1016/j.ultramic.2024.114083","DOIUrl":"10.1016/j.ultramic.2024.114083","url":null,"abstract":"<div><div>The rich information of electron energy-loss spectroscopy (EELS) comes from the complex inelastic scattering process whereby fast electrons transfer energy and momentum to atoms, exciting bound electrons from their ground states to higher unoccupied states. To quantify EELS, the common practice is to compare the cross-sections integrated within an energy window or fit the observed spectrum with theoretical differential cross-sections calculated from a generalized oscillator strength (GOS) database with experimental parameters. The previous Hartree–Fock-based and DFT-based GOS are calculated from Schrödinger’s solution of atomic orbitals, which does not include the full relativistic effects. Here, we attempt to go beyond the limitations of the Schrödinger solution in the GOS tabulation by including the full relativistic effects using the Dirac equation within the local density approximation, which is particularly important for core–shell electrons of heavy elements with strong spin–orbit coupling. This has been done for all elements in the periodic table (up to Z = 118) for all possible excitation edges using modern computing capabilities and parallelization algorithms. The relativistic effects of fast incoming electrons were included to calculate cross-sections that are specific to the acceleration voltage. We make these tabulated GOS available under an open-source license to the benefit of both academic users and to allow integration into commercial solutions.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"269 ","pages":"Article 114083"},"PeriodicalIF":2.1,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142792288","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

Aberration calculation of microlens array using differential algebraic method 微透镜阵列像差的微分代数计算。

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2024-11-30 DOI: 10.1016/j.ultramic.2024.114085

Jintao Hu, Lei Yue, Yihao Ma, Fu Liu, Yongfeng Kang

{"title":"Aberration calculation of microlens array using differential algebraic method","authors":"Jintao Hu, Lei Yue, Yihao Ma, Fu Liu, Yongfeng Kang","doi":"10.1016/j.ultramic.2024.114085","DOIUrl":"10.1016/j.ultramic.2024.114085","url":null,"abstract":"<div><div>Microlens array (MLA), through which all the sub-beams are focused, is widely used in multi-electron-beam systems. In this work, based on the differential algebraic (DA) method, we propose an approach in calculating the high-order aberrations for both axial and off-axial microlenses, considering the multipole fields that are introduced by the neighborhood structures in MLA, as well as the rotationally symmetric field. To perform the DA calculation, the electric fields of the microlenses are analyzed by using the azimuthal Fourier analysis and the Fourier-Bessel series Expansion. The resulting field components, including both rotationally symmetric field and the multipole fields, are transferred into DA arguments and operated as per DA methodology. Then, by developing and employing the DA theory and algorithm, the primary and high-order aberrations are calculated and obtained simultaneously for both the axial and off-axial microlenses by tracing only one reference ray. Finally, we calculate, analyze and discuss the primary and high-order aberrations of two example MLAs, for both axial and off-axial microlenses. The effects of the dodecapole fields on the aberrations are also analyzed.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"269 ","pages":"Article 114085"},"PeriodicalIF":2.1,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142792283","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

Effect of the surrounding environment on electron beam irradiation damage of enhanced green fluorescent protein 周围环境对电子束辐照增强绿色荧光蛋白损伤的影响

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2024-11-25 DOI: 10.1016/j.ultramic.2024.114082

Haruyoshi Osakabe , Mihiro Suzuki , Toshiki Shimizu , Hiroki Minoda

{"title":"Effect of the surrounding environment on electron beam irradiation damage of enhanced green fluorescent protein","authors":"Haruyoshi Osakabe , Mihiro Suzuki , Toshiki Shimizu , Hiroki Minoda","doi":"10.1016/j.ultramic.2024.114082","DOIUrl":"10.1016/j.ultramic.2024.114082","url":null,"abstract":"<div><div>Fluorescent proteins exhibit fluorescence and photoconversion, which are used to study biological phenomena. Among these, enhanced green fluorescent protein (EGFP) emits cathodoluminescence when irradiated with electron beams; this phenomenon has numerous applications in new research tools for biological phenomena. However, bleaching during electron irradiation is a major problem. Generally, the presence of water is important for biological samples, and structural observations are often performed under cryogenic conditions. One of the advantages of cryogenic conditions is the stabilization of the sample due to cooling. However, it is unclear which factor is more effective: the presence of water molecules or cryogenic preservation. To explore the stabilizing factors of the sample structure, we prepared four environments around the sample–dry at room temperature, wet at room temperature, dry at low temperature, and under cryogenic conditions–and investigated the electron beam irradiation damage by measuring the fluorescence emission spectra. Emission intensity from EGFP was attenuated, and the peak was red-shifted by electron beam irradiation; however, the intensity attenuation was fast under dry conditions at low temperature and slow under wet conditions at room temperature. These results imply that sample cooling has no significant effect on the stability of the EGFP chromophore and that the presence of water molecules is extremely important.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"268 ","pages":"Article 114082"},"PeriodicalIF":2.1,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142746083","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

Direct electron detection for EBSD of low symmetry & beam sensitive ceramics 用于低对称性和光束敏感陶瓷 EBSD 的直接电子探测

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2024-11-23 DOI: 10.1016/j.ultramic.2024.114079

Nicolò M. Della Ventura , Andrew R. Ericks , McLean P. Echlin , Kalani Moore , Tresa M. Pollock , Matthew R. Begley , Frank W. Zok , Marc De Graef , Daniel S. Gianola

{"title":"Direct electron detection for EBSD of low symmetry & beam sensitive ceramics","authors":"Nicolò M. Della Ventura , Andrew R. Ericks , McLean P. Echlin , Kalani Moore , Tresa M. Pollock , Matthew R. Begley , Frank W. Zok , Marc De Graef , Daniel S. Gianola","doi":"10.1016/j.ultramic.2024.114079","DOIUrl":"10.1016/j.ultramic.2024.114079","url":null,"abstract":"<div><div>Electron backscatter diffraction (EBSD) is a powerful tool for determining the orientations of near-surface grains in engineering materials. However, many ceramics present challenges for routine EBSD data collection and indexing due to small grain sizes, high crack densities, beam and charge sensitivities, low crystal symmetries, and pseudo-symmetric pattern variants. Micro-cracked monoclinic hafnia, tetragonal hafnon, and hafnia/hafnon composites exhibit all such features, and are used in the present work to show the efficacy of a novel workflow based on a direct detecting EBSD sensor and a state-of-the-art pattern indexing approach. At 5 and 10 keV primary beam energies (where beam-induced damage and surface charge accumulation are minimal), the direct electron detector produces superior diffraction patterns with 10x lower doses compared to a phosphor-coupled indirect detector. Further, pseudo-symmetric variant-related indexing errors from a Hough-based approach (which account for at least 4%-14% of map areas) are easily resolved by dictionary indexing. In short, the workflow unlocks fundamentally new opportunities to characterize materials historically unsuited for EBSD.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"268 ","pages":"Article 114079"},"PeriodicalIF":2.1,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142721238","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