Ultramicroscopy最新文献_第9页

Bi-directional LEEM and eV-TEM spectroscopy on a graphene-hBN heterostack 石墨烯- hbn异质堆的双向LEEM和eV-TEM光谱研究

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2025-02-16 DOI: 10.1016/j.ultramic.2025.114117

Peter S. Neu , Eugene E. Krasovskii , Rudolf M. Tromp , Sense Jan van der Molen

{"title":"Bi-directional LEEM and eV-TEM spectroscopy on a graphene-hBN heterostack","authors":"Peter S. Neu , Eugene E. Krasovskii , Rudolf M. Tromp , Sense Jan van der Molen","doi":"10.1016/j.ultramic.2025.114117","DOIUrl":"10.1016/j.ultramic.2025.114117","url":null,"abstract":"<div><div>Van der Waals heterostacks can exhibit emergent properties as a result of the coupling between the individual layers stacked. Here we focus on heterostacks of graphene and hBN, and study both coherent electron resonances (or unoccupied states) and inelastic losses. For this, we measure electron reflection and transmission spectra of the stack, as a function of electron energy. Special attention is paid to the symmetry upon flipping the heterostack, i.e., whether the electrons are first incident on the graphene or on the hBN surface: whereas electron reflection may be sensitive to sample orientation, electron transmission should not. Experimentally, we compare LEEM (reflection) and eV-TEM (transmission) IV spectra measured on free-standing graphene-hBN heterostacks with either the graphene or hBN side facing the LEEM objective lens. Resonances and inelastic loss are first modeled with the help of a simple wave interference toy model inspired by optics. More advanced calculations are performed to obtain the spatially resolved density of unoccupied states in the heterostack. We relate these calculations to the measured spectra, taking into account the finite probing depth of the reflected electron beam.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"271 ","pages":"Article 114117"},"PeriodicalIF":2.1,"publicationDate":"2025-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143600543","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

Erratum to "The impact of electric field strength on the accuracy of boron dopant quantification in silicon using atom probe tomography" “电场强度对用原子探针层析法定量硅中硼掺杂的准确性的影响”的勘误。

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2025-02-09 DOI: 10.1016/j.ultramic.2025.114115

Bavley Guerguis , Ramya Cuduvally , Richard J.H. Morris , Gabriel Arcuri , Brian Langelier , Nabil Bassim

引用次数: 0

Effects of laser wavelength and pulse energy on the evaporation behavior of TiN coatings in atom probe tomography: A multi-instrument study 激光波长和脉冲能量对原子探针层析TiN涂层蒸发行为的影响：多仪器研究。

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2025-01-17 DOI: 10.1016/j.ultramic.2025.114105

Maximilian Schiester , Helene Waldl , Katherine P. Rice , Marcus Hans , Daniel Primetzhofer , Nina Schalk , Michael Tkadletz

{"title":"Effects of laser wavelength and pulse energy on the evaporation behavior of TiN coatings in atom probe tomography: A multi-instrument study","authors":"Maximilian Schiester , Helene Waldl , Katherine P. Rice , Marcus Hans , Daniel Primetzhofer , Nina Schalk , Michael Tkadletz","doi":"10.1016/j.ultramic.2025.114105","DOIUrl":"10.1016/j.ultramic.2025.114105","url":null,"abstract":"<div><div>The impact of the laser wavelength on accuracy in elemental composition analysis in atom probe tomography (APT) was investigated. Three different commercial atom probe systems — LEAP 3000X HR, LEAP 5000 XR, and LEAP 6000 XR — were systematically compared for a TiN model coating studying the effect of shorter laser wavelengths, especially in the deep ultraviolet (DUV) range, on the evaporation behavior. The findings demonstrate that the use of shorter wavelengths enhances the accuracy in elemental composition, while maintaining similar electric field strengths. Thus, thermal effects are reduced, which in turn improves mass resolving power. An important aspect of this research includes the estimation of energy density ratios of the different instruments. The reduction in wavelength is accompanied by increasing energy densities due to smaller laser spot sizes. Furthermore, advancements in the detector technology were studied. Finally, the detector dead-times were determined and dead-zones were evaluated to investigate the ion pile-up behavior in APT measurements of nitrides with the LEAP 6000 XR.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"270 ","pages":"Article 114105"},"PeriodicalIF":2.1,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143012396","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

A comparison of energy dispersive spectroscopy in transmission scanning electron microscopy with scanning transmission electron microscopy 透射扫描电镜与扫描透射电镜能量色散谱的比较。

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2025-01-17 DOI: 10.1016/j.ultramic.2025.114106

Jennifer L.W. Carter , Tugce Karakulak Uz , Buhari Ibrahim , Jeffrey S. Pigott , Jerard V. Gordon

{"title":"A comparison of energy dispersive spectroscopy in transmission scanning electron microscopy with scanning transmission electron microscopy","authors":"Jennifer L.W. Carter , Tugce Karakulak Uz , Buhari Ibrahim , Jeffrey S. Pigott , Jerard V. Gordon","doi":"10.1016/j.ultramic.2025.114106","DOIUrl":"10.1016/j.ultramic.2025.114106","url":null,"abstract":"<div><div>The objective of this work was to explore the capabilities of a field emission gun scanning electron microscope (FEG-SEM) equipped with a transmission scanning electron detector (TSEM) and energy dispersive spectroscopy (EDS) to identify nanoscale chemical heterogeneities in a gas atomization reaction synthesis (GARS) steel sample. The results of this analysis were compared to the same study conducted with scanning transmission electron microscopy (STEM) with EDS mapping. TSEM-EDS was performed using the standard spectral analysis approach, i.e., pixel-by-pixel identification of elements from the spectra, and a new principal component analysis approach to detect regions of similar spectra before identifying elemental contributions to each spectrum. It was determined that features over 200 nm were detectable with the TSEM-EDS standard spectra analysis technique but the PCA analysis approach was necessary for observing smaller features that contained trace elements. Monte Carlo simulations indicated that the spatial resolution expected from a 150 nm thick foil was consistent with those observed in experimental analysis. Simulations also confirm that thinner samples enable higher spatial resolution scans although smaller interaction volumes may require longer acquisition times.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"270 ","pages":"Article 114106"},"PeriodicalIF":2.1,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143041510","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

Site-specific plan-view (S)TEM sample preparation from thin films using a dual-beam FIB-SEM 使用双光束FIB-SEM从薄膜中制备特定位置的平面视图(S)TEM样品。

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2025-01-13 DOI: 10.1016/j.ultramic.2025.114104

Supriya Ghosh, Fengdeng Liu, Sreejith Nair, Rishi Raj, Bharat Jalan, K. Andre Mkhoyan

{"title":"Site-specific plan-view (S)TEM sample preparation from thin films using a dual-beam FIB-SEM","authors":"Supriya Ghosh, Fengdeng Liu, Sreejith Nair, Rishi Raj, Bharat Jalan, K. Andre Mkhoyan","doi":"10.1016/j.ultramic.2025.114104","DOIUrl":"10.1016/j.ultramic.2025.114104","url":null,"abstract":"<div><div>To fully evaluate the atomic structure, and associated properties of materials using transmission electron microscopy, examination of samples from three non-collinear orientations is needed. This is particularly challenging for thin films and nanoscale devices built on substrates due to limitations with plan-view sample preparation. In this work, a new method for preparation of high-quality, site-specific, plan-view TEM samples from thin-films grown on substrates, is presented and discussed. It is based on using a dual-beam focused ion beam scanning electron microscope (FIB-SEM) system. To demonstrate the method, the samples were prepared from thin films of perovskite oxide BaSnO<sub>3</sub> grown on a SrTiO<sub>3</sub> substrate and metal oxide IrO<sub>2</sub> on a TiO<sub>2</sub> substrate, ranging from 20–80 nm in thicknesses using molecular beam epitaxy. While the method is optimized for the thin films, it can be extended to other site-specific plan-view samples and devices build on wafers. Aberration-corrected STEM was used to evaluate the quality of the samples and their applicability for atomic-resolution imaging and analysis.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"270 ","pages":"Article 114104"},"PeriodicalIF":2.1,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143012410","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

Semicircular-aperture illumination scanning transmission electron microscopy 半圆孔径照明扫描透射电子显微镜。

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2025-01-13 DOI: 10.1016/j.ultramic.2025.114103

Akira Yasuhara , Fumio Hosokawa , Sadayuki Asaoka , Teppei Akiyama , Tomokazu Iyoda , Chikako Nakayama , Takumi Sannomiya

引用次数: 0

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