Ultramicroscopy最新文献_第8页

EstimateNoiseSEM: A novel framework for deep learning based noise estimation of scanning electron microscopy images EstimateNoiseSEM：一种基于深度学习的扫描电镜图像噪声估计新框架

IF 2.1 3区工程技术 Q2 MICROSCOPY

Ultramicroscopy

Pub Date : 2025-06-28 DOI: 10.1016/j.ultramic.2025.114192

Sheikh Shah Mohammad Motiur Rahman , Michel Salomon , Sounkalo Dembélé

This paper introduces a framework (EstimateNoiseSEM) to automate noise estimation in scanning electron microscopy (SEM) images. Within this framework, a classification network selection mechanism facilitates the choice of a more optimized classification approach. Consequently, the classification stage determines the image’s noise type, while the regression model predicts the corresponding noise level. Noise estimation, which includes the noise type and level, is necessary to perform denoising in most cases. This study targeted the noise in scanning electron microscopy (SEM) images. Indeed, depending on the dwell time, the SEM produces different types of noise (Gaussian or Gamma) that can pose uncertainty problems during denoising. That is why, the multi-stage scheme based on deep learning was proposed in this study. The proposed approach performed better in Gaussian noise classification with more than 80% Accuracy, Precision, Recall, and F1-score on synthetic noisy samples and 0.98+/-0.01 root squared error in Gaussian noise classification. The classification network once achieved 97% of accuracy for Gaussian noise classification which decreased to 80% later on because of the uncertainty of Gamma noise levels. However, this study also provides detailed insights into the Gamma noise estimation process. These insights may guide us or the community in developing deep learning-based Gamma noise estimation techniques.

介绍了一个用于扫描电子显微镜图像噪声自动估计的框架（EstimateNoiseSEM）。在此框架内，分类网络选择机制有助于选择更优化的分类方法。因此，分类阶段决定了图像的噪声类型，而回归模型预测了相应的噪声水平。在大多数情况下，噪声估计是进行去噪的必要条件，噪声估计包括噪声的类型和电平。本文针对扫描电镜图像中的噪声进行了研究。实际上，根据停留时间的不同，扫描电镜会产生不同类型的噪声（高斯或伽马），这些噪声会在去噪过程中造成不确定性问题。因此，本研究提出了基于深度学习的多阶段方案。该方法在高斯噪声分类中表现较好，对合成噪声样本的准确率、精密度、召回率和f1得分均超过80%，高斯噪声分类的均方根误差为0.98+/-0.01。该分类网络对高斯噪声的分类准确率一度达到97%，后来由于伽马噪声水平的不确定性，准确率下降到80%。然而，这项研究也提供了伽马噪声估计过程的详细见解。这些见解可以指导我们或社区开发基于深度学习的伽马噪声估计技术。

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引用次数: 0

Differences between differential phase contrast and electron holographic measurements of a GaN p-n junction GaN p-n结差相衬和电子全息测量的差异

IF 2.1 3区工程技术 Q2 MICROSCOPY

Ultramicroscopy

Pub Date : 2025-06-21 DOI: 10.1016/j.ultramic.2025.114191

Laura Niermann

Modern semiconductor devices require control of the electrostatic potential landscape at nanometer scale, which is especially important for materials like the Group III-Nitrides, where polarization effects cause additional sheet charges at interfaces. In this work two complementary electron microscopic methods, differential phase contrast (DPC) and electron holography (EH), are used for characterization of a GaN p–n junction in one and the same sample. In comparison, the values obtained for the junction’s characteristics, like the built-in potential step, the maximum fields strength, and the width of the space charge region, were significantly larger and also closer to the expected values, when measured by means of EH. A key difference in the measurements is the vastly lower illumination dose rates within the EH experiments. Therefore, the lower generation rate of electron–hole pairs might lead to a lower beam induced bias during the EH measurement. These findings demonstrate that in future experiments the impact of the electron illumination must be considered for accurate nanoscale electrostatic field and potential measurements.

现代半导体器件需要在纳米尺度上控制静电势，这对于像iii族氮化物这样的材料尤其重要，因为极化效应会在界面处引起额外的片电荷。在这项工作中，两种互补的电子显微镜方法，差分相对比（DPC）和电子全息（EH），用于表征一个GaN p-n结在一个和相同的样品。相比之下，用EH测量时得到的结的特性值，如内置电位阶跃、最大场强和空间电荷区宽度，都明显更大，也更接近期望值。测量中的一个关键区别是EH实验中的照明剂量率要低得多。因此，较低的电子-空穴对产生率可能导致在EH测量过程中较低的光束诱导偏置。这些发现表明，在未来的实验中，电子照明的影响必须考虑到精确的纳米级静电场和电位测量。

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引用次数: 0

TEM-EDS microanalysis: Comparison between different electron sources, accelerating voltages and detection systems TEM-EDS微分析：不同电子源、加速电压和检测系统的比较

IF 2.1 3区工程技术 Q2 MICROSCOPY

Ultramicroscopy

Pub Date : 2025-06-17 DOI: 10.1016/j.ultramic.2025.114201

Roberto Conconi , María del Mar Abad Ortega , Fernando Nieto , Paolo Buono , Giancarlo Capitani

Two TEM-EDS quantification methods based on standards of known compositions, namely the Cliff and Lorimer approximation and the absorption correction method based on electroneutrality are employed and the results obtained with three different TEMs and EDS systems, compared. The three TEM instruments differ in source type (field emission vs. thermionic), accelerating voltage (200 vs. 300 kV) and EDS system type (4 in-column silicon drift detector (SDD) vs. single SDD). We found that EDS calibration appears to be “strictly instrument specific”, i.e., no universally valid k-factors can exist, but only k-factor sets for a specific combination of microscope and EDS system. As expected, 4-in column SDD systems, because of their larger sensitive areas compared to classical single SDD, are more efficient in data collection and, therefore, have lower detection limits. However, other sources of error may influence the final output, sometimes subverting the expectations. EDS analyses performed with FEG-TEMs exhibit lower radiation-induced migration of weakly bounded elements than TEMs equipped with a conventional source and lower beam current. This result may be explained by the smaller spot size used with the conventional TEM that in total led to a higher electron dose per sample atom. In addition, this work confirms that the absorption correction method is to be preferred whenever dealing with thick and/or dense samples, whereas the Cliff and Lorimer approximation, because simpler and faster, in all the other cases. Finally, we renew the necessity to determine two distinct k_O/Si factors, one for lighter and one for denser compounds.

采用Cliff和Lorimer近似法和基于电中性的吸收校正法两种基于已知组分标准的TEM-EDS定量方法，并比较了三种不同tem和EDS体系的结果。这三种TEM仪器在源类型（场发射vs热离子）、加速电压（200 vs 300 kV）和EDS系统类型（4列硅漂移检测器（SDD） vs单列SDD）上有所不同。我们发现EDS校准似乎是“严格特定于仪器”，即不存在普遍有效的k因子，而只有特定显微镜和EDS系统组合的k因子集。正如预期的那样，4-in柱SDD系统，由于与传统的单SDD相比具有更大的敏感区域，因此在数据收集方面更有效，因此具有更低的检测限。但是，其他错误来源可能会影响最终输出，有时会破坏预期。用feg - tem进行的EDS分析显示，弱边界元素的辐射诱导迁移比配备常规源和较低光束电流的tem低。这一结果可以解释为使用传统TEM的光斑尺寸较小，总的来说导致每个样品原子的电子剂量较高。此外，这项工作证实了吸收校正方法在处理厚和/或致密样品时是首选的，而Cliff和Lorimer近似在所有其他情况下都更简单，更快。最后，我们重申有必要确定两个不同的kO/Si因子，一个用于较轻的化合物，一个用于较致密的化合物。

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引用次数: 0

Improving the elemental and imaging accuracy in atom probe tomography of (Ti,Si)N single and multilayer coatings using isotopic substitution of N 用N同位素取代提高（Ti,Si）N单层和多层涂层原子探针层析成像的元素和成像精度

IF 2.1 3区工程技术 Q2 MICROSCOPY

Ultramicroscopy

Pub Date : 2025-06-17 DOI: 10.1016/j.ultramic.2025.114200

Saeideh Naghdali , Maximilian Schiester , Helene Waldl , Velislava Terziyska , Marcus Hans , Daniel Primetzhofer , Nina Schalk , Michael Tkadletz

This study addresses the challenges in analyzing (Ti,Si)N coatings using atom probe tomography (APT). Overlapping mass-to-charge state ratios in APT mass spectra hinder unambiguous identification of Si and N, thus, isotopic substitution of naturally abundant nitrogen by ¹⁵N-enriched nitrogen was applied to disentangle the mass-spectral overlaps. A series of model coatings, namely, Ti-N, Si-N, and Ti-Si-N single layer coatings were utilized to investigate elemental accuracy, while their corresponding multilayer coatings were used to assess lateral resolution and imaging accuracy. The coatings were sputter-deposited using i) naturally abundant nitrogen and ii) ¹⁵N-enriched nitrogen, respectively. Subsequently, the coatings were analyzed with a LEAP 5000 XR atom probe. Accuracy in obtained concentrations was cross-validated with elastic recoil detection analysis (ERDA) combined with Rutherford backscattering spectrometry (RBS). The investigation showed that isotopic substitution allows to differentiate the Si and N peaks in the mass spectra and significantly reduces compositional discrepancies between APT and ERDA/RBS results. Despite remaining minor peak overlaps, which can result in inaccuracies in determining the elemental composition, isotopic substitution has proven to be an effective method for peak differentiation and correcting the obtained elemental composition of Ti-Si-N. Moreover, isotopic substitution can predominantly increase the elemental accuracy and imaging accuracy of APT measurements of multilayer coatings.

本研究解决了使用原子探针断层扫描（APT）分析（Ti,Si）N涂层的挑战。APT质谱中重叠的质荷态比阻碍了对Si和N的明确识别，因此，用富含15n的氮同位素取代天然丰富的氮来解开质谱重叠。使用一系列模型涂层，即Ti-N、Si-N和Ti-Si-N单层涂层来研究元素精度，而使用相应的多层涂层来评估横向分辨率和成像精度。镀层分别采用i)天然富氮和ii)富15n氮溅射沉积。随后，用LEAP 5000 XR原子探针对涂层进行分析。采用弹性反冲检测分析（ERDA）和卢瑟福后向散射光谱法（RBS）交叉验证所得浓度的准确性。研究表明，同位素取代可以区分质谱中的Si和N峰，并显著降低了APT和ERDA/RBS结果之间的成分差异。尽管仍然存在少量的峰重叠，这可能导致确定元素组成的不准确性，但同位素取代已被证明是一种有效的峰区分方法，并纠正所获得的Ti-Si-N元素组成。此外，同位素取代能显著提高多层涂层APT测量的元素精度和成像精度。

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引用次数: 0

Can low energy (1–20 eV) electron microscopy produce damage-free images of biological samples? 低能量（1-20 eV）电子显微镜能产生无损伤的生物样品图像吗？

IF 2.1 3区工程技术 Q2 MICROSCOPY

Ultramicroscopy

Pub Date : 2025-06-16 DOI: 10.1016/j.ultramic.2025.114197

Yi Zheng, Léon Sanche

Electron microscopy constitutes an efficient and well-established method to visualize biological material on the nanoscale. The image is usually produced by a high energy electron beam, which can damage the biological sample. To reduce image degradation, Neu et al. [Ultramicroscopy 222 (2021) 113,199] recently suggested the possibility of damage-free imaging of such samples at nm resolution using as a probe low energy electron (LEEs). The aims of the present article are to 1) present a simple and short description of LEE inelastic scattering and attachment in molecular solids in the 0–20 eV range, 2) show that principally due to the formation of transient anions (TAs) in biological material, by temporary LEE attachment to molecular sites, damage-free electron microscopy may be difficult to achieve and 3) suggest specimen conditions that reduce the damage produced by TAs to inflict minimum damage to biological samples in LEE microscopy. We provide examples of lesions induced by electrons of energies below 3 eV in short DNA strands composed of 16 base-pair oligonucleotides and on the 1–20 eV dependence of effective damage yields from LEE-bombarded plasmid DNA. The damaged samples were produced from 5-monolayer films lyophilized on tantalum substrates and transferred to ultra-high vacuum to be bombarded with LEEs. The products were identified and quantified ex-vacuo by LC-MS-MS and electrophoresis, respectively. Such effective yields, and the corresponding absolute cross sections derived from model analysis, should allow estimating beam damage and image quality in the visualization of thin biological films by LEE microscopy.

电子显微镜是一种在纳米尺度上观察生物材料的有效且成熟的方法。图像通常是由高能电子束产生的，这可能会破坏生物样品。为了减少图像退化，Neu等人[超微显微镜222(2021)113,199]最近提出了在纳米分辨率下使用低能量电子（LEEs）作为探针对这些样品进行无损伤成像的可能性。本文的目的是：1)在0-20 eV范围内对分子固体中LEE的非弹性散射和附着进行简单而简短的描述；2)表明，主要由于生物材料中瞬态阴离子（TAs）的形成，通过LEE对分子位点的临时附着，无损伤电子显微镜可能难以实现，并且3)建议在LEE显微镜中减少TAs产生的损伤以对生物样品造成最小损伤的样品条件。我们提供了能量低于3 eV的电子在由16个碱基对寡核苷酸组成的短DNA链中引起损伤的例子，以及1-20 eV依赖于lee轰击质粒DNA的有效损伤产量。损坏的样品是由在钽衬底上冻干的5层单层薄膜制成的，然后转移到超高真空中用LEEs轰击。分别用LC-MS-MS和电泳对产物进行鉴定和定量。这样的有效产率，以及从模型分析中得出的相应的绝对横截面，应该可以通过LEE显微镜来估计生物薄膜可视化中的光束损伤和图像质量。

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引用次数: 0

Valence EELS study of the composition of a liquid phase in a Janus Sn-Ge nanoparticle over a temperature range of 250–750 °C 在250-750℃的温度范围内，对Janus Sn-Ge纳米颗粒液相组成的价态EELS研究

IF 2.1 3区工程技术 Q2 MICROSCOPY

Ultramicroscopy

Pub Date : 2025-06-16 DOI: 10.1016/j.ultramic.2025.114199

Olha Khshanovska, Aleksandr Kryshtal

Mapping the composition of liquid alloy nanoparticles in TEM at relatively low electron doses is essential for emerging nanotechnologies. In this work, we used volume and surface plasmon energies to determine the composition across different regions of a single Sn-Ge nanoparticle over a temperature range of 250–750 °C. A 53 nm Janus nanoparticle, composed of liquid Sn and solid Ge sides, was heated in a TEM, inducing the gradual dissolution of Ge into liquid Sn. Low-loss electron energy loss spectral images were acquired at 50 °C intervals, and plasmon energies were accurately measured using model-based fitting.

We demonstrated that the free-electron gas Drude model, combined with Zen’s law of alloy volume-concentration relation, enables the reliable determination of the composition of liquid Sn-Ge alloy from both surface and volume plasmon energy shifts. The determined compositions of the liquid alloy were consistent with EDX measurements and the liquidus line of the phase diagram. A homogeneous distribution of chemical elements in the liquid Sn-Ge alloy was revealed. At the same time, the composition on the Ge side of the nanoparticle was inhomogeneous, indicating the formation of a thin liquid shell over the solid Ge core. As a result, Ge in the Sn-Ge Janus nanoparticle exhibited highly tunable surface plasmon resonance, with its energy varying between 10.75 and 9.25 eV over a temperature range of 250–750 °C.

在相对较低的电子剂量下，用透射电镜绘制液态合金纳米颗粒的组成图对新兴纳米技术至关重要。在这项工作中，我们使用体积和表面等离子体能量来确定单个Sn-Ge纳米颗粒在250-750°C温度范围内不同区域的组成。在透射电镜下加热由液态Sn和固态Ge两侧组成的53nm Janus纳米颗粒，使Ge逐渐溶解到液态Sn中。在50°C区间获得了低损耗电子能量损失光谱图像，并使用基于模型的拟合精确测量了等离子体能量。我们证明了自由电子气体Drude模型，结合Zen的合金体积-浓度关系定律，可以从表面和体积等离子体能量位移两方面可靠地确定液态Sn-Ge合金的成分。液相合金的组成与EDX测量结果和相图的液相线相一致。结果表明，液态Sn-Ge合金中化学元素分布均匀。同时，纳米颗粒Ge侧的成分不均匀，表明在固体Ge核上形成了薄的液体壳。结果表明，在250 ~ 750℃的温度范围内，Sn-Ge Janus纳米粒子中的Ge表现出高度可调谐的表面等离子体共振，其能量在10.75 ~ 9.25 eV之间变化。

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引用次数: 0

Electron backscattering coefficient, material contrast and response function of BSE- detectors in scanning electron microscopy 扫描电镜下BSE-探测器的电子后向散射系数、材料对比和响应函数

IF 2.1 3区工程技术 Q2 MICROSCOPY

Ultramicroscopy

Pub Date : 2025-06-11 DOI: 10.1016/j.ultramic.2025.114196

E.I. Rau, S.V. Zaitsev

An empirical expression for the electron backscattering coefficient η, mean backscattered energy coefficient ε and response function F of backscattered electrons (BSE) detectors in scanning electron microscope (SEM) are established for bulk specimens in dependence of atomic number Z and primary electrons energy E_B.

The obtained expressions give more precisely data of η than all previous publications in the wide energy range E_B 1–30 keV. They were used to describe the dependence of the BSE signal I_S from atomic number of the target material Z and SEM accelerating voltage E_B. The image contrast as a function of Z -differences and E_B is considered. Particular attention is paid to the influence of the response function F on the formation of the I_S signal. All consideration were carried out with commercial semiconductor or scintillation BSE – detectors installed in SEM in standard position below from objective lens and right above the sample. The characteristics were compared with similar of the multichannel plate (MCP) detector.

建立了扫描电子显微镜下背散射电子（BSE）探测器的电子背散射系数η、平均背散射能量系数ε和响应函数F与原子序数Z和一次电子能量EB的经验表达式。所得到的表达式比以往所有的文献在eb1 - 30kev宽能量范围内给出了更精确的η数据。用它们描述了靶材料原子序数Z和SEM加速电压EB对BSE信号的依赖关系。考虑了图像对比度作为Z差和EB的函数。特别注意响应函数F对is信号形成的影响。所有的考虑都是用商用半导体或闪烁BSE探测器进行的，这些探测器安装在SEM中，位于物镜下方和样品上方的标准位置。并与同类多通道板探测器的特性进行了比较。

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引用次数: 0

Simulation-based super-resolution EBSD for measurements of relative deformation gradient tensors 基于仿真的超分辨率EBSD相对变形梯度张量测量

IF 2.1 3区工程技术 Q2 MICROSCOPY

Ultramicroscopy

Pub Date : 2025-06-10 DOI: 10.1016/j.ultramic.2025.114180

Aimo Winkelmann , Grzegorz Cios , Konrad Perzyński , Tomasz Tokarski , Klaus Mehnert , Łukasz Madej , Piotr Bała

We summarize a data analysis approach for electron backscatter diffraction (EBSD) which uses high-resolution Kikuchi pattern simulations to measure isochoric relative deformation gradient tensors from experimentally measured Kikuchi patterns of relatively low resolution. Simulation-based supersampling of the theoretical test diffraction patterns enables a significant precision improvement of tensor parameters obtained in best-fit determinations of strains and orientations from low-resolution experimental patterns. As an application, we demonstrate high-resolution orientation and strain analysis for the model case of hardness test indents on a Si(100) wafer, using Kikuchi patterns of variable resolution. The approach shows noise levels near

1 \times 1 0^{- 4}

in the relative deviatoric strain norm and in the relative rotation angles on nominally strain-free regions of the silicon wafer. The strain and rotation measurements are interpreted by finite element simulations. While confirming the basic findings of previously published studies, the present approach enables a potential reduction in the necessary pattern data size by about two orders of magnitude. We estimate that pattern resolutions in the order of 256 × 256 pixels should be enough to solve a majority of EBSD analysis tasks using pattern matching techniques.

本文总结了一种电子背散射衍射（EBSD）的数据分析方法，该方法利用高分辨率菊池图模拟来测量实验测量的相对低分辨率菊池图的等时相对变形梯度张量。基于模拟的理论测试衍射图的超采样使得从低分辨率实验图中获得的应变和方向的最佳拟合确定中获得的张量参数的精度得到显著提高。作为一个应用，我们展示了高分辨率的取向和应变分析模型案例的硬度测试压痕在硅（100）晶圆上，使用变分辨率菊池图案。该方法表明，在硅片的名义上无应变区域的相对偏应变范数和相对旋转角度中，噪声水平接近1×10−4。应变和旋转测量由有限元模拟解释。虽然证实了以前发表的研究的基本发现，但目前的方法可以将必要的模式数据大小减少大约两个数量级。我们估计，256 × 256像素的模式分辨率应该足以解决大多数使用模式匹配技术的EBSD分析任务。

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引用次数: 0

Measurement of electron beam induced sample heating in SEM experiments 扫描电镜实验中电子束诱导样品加热的测量

IF 2.1 3区工程技术 Q2 MICROSCOPY

Ultramicroscopy

Pub Date : 2025-06-09 DOI: 10.1016/j.ultramic.2025.114195

Christina Koenig, Alice Bastos da Silva Fanta, Joerg R. Jinschek

Scanning Electron Microscopy (SEM) experiments provide detailed insights into material microstructures, enabling high-resolution imaging as well as crystallographic analysis through advanced techniques like Electron Backscatter Diffraction (EBSD). However, the interaction of the high-energy electron beam with the material can lead to localized heating, which may significantly impact specimen integrity, especially in applications requiring prolonged beam exposure, for instance when mapping the crystal structure using EBSD. This study examines electron-beam-induced heating effects on a model metal sample (iron), directly measuring the locally deposited electron beam energy with a MEMS-based heating device and validating these measurements through simulations, including Monte Carlo and Finite Element methods. The analysis focuses on the effects of various experimental parameters such as acceleration voltage (from 5 to 30 kV), beam current (from 0.17 nA to 22 nA), dwell time (from 1µs to 1 ms) and sample tilt (0° to 70°). The findings reveal that local sample temperatures can increase by up to 70 °C during EBSD experiments, primarily affected by the choice in beam current and acceleration voltage, with beam current having the most significant impact.

扫描电子显微镜（SEM）实验提供了对材料微观结构的详细见解，通过电子背散射衍射（EBSD）等先进技术实现高分辨率成像以及晶体学分析。然而，高能电子束与材料的相互作用会导致局部加热，这可能会严重影响样品的完整性，特别是在需要长时间光束暴露的应用中，例如使用EBSD绘制晶体结构时。本研究考察了电子束对模型金属样品（铁）的加热效应，使用基于mems的加热装置直接测量了局部沉积的电子束能量，并通过模拟（包括蒙特卡罗和有限元方法）验证了这些测量结果。分析的重点是各种实验参数的影响，如加速电压（从5到30 kV），光束电流（从0.17 nA到22 nA），停留时间（从1µs到1 ms）和样品倾斜（0°到70°）。研究结果表明，在EBSD实验中，局部样品温度可升高70°C，主要受束流和加速电压选择的影响，其中束流的影响最大。

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引用次数: 0

SEM characterization technique for air-sensitive all-solid-state lithium battery materials 气敏全固态锂电池材料的SEM表征技术

IF 2.1 3区工程技术 Q2 MICROSCOPY

Ultramicroscopy

Pub Date : 2025-06-08 DOI: 10.1016/j.ultramic.2025.114194

Hongmin Zhou , Zhenqi Gu , Ming Li , Minghui Fan , Zhi Zhao , Shengquan Fu , Kai Wang

Scanning electron microscopy (SEM) is an important tool for investigating the surface morphologies, chemical compositions, and failure mechanisms of functional materials. However, the microstructures of some materials change during the transfer to SEM, resulting in the inability to characterize them accurately because of the air-sensitive nature of the materials (e.g., battery materials and active metals). Herein, we have designed an airtight transfer box that is simple and feasible for the SEM characterization of air-sensitive materials, realizing that air-sensitive materials are not exposed to air throughout the transfer process. In addition, the ratio of the cathode active material to solid-state electrolytes in the composite cathode of all-solid-state lithium batteries is nondestructively investigated using an airtight transfer box, providing theoretical guidance for the design of high-specific energy composite cathodes.

扫描电子显微镜（SEM）是研究功能材料表面形貌、化学成分和失效机制的重要工具。然而，一些材料的微观结构在转移到SEM的过程中发生了变化，由于材料（如电池材料和活性金属）的空气敏感性，导致无法准确表征它们。本文设计了一种简单可行的气敏材料SEM表征气密传递箱，实现了气敏材料在整个传递过程中不与空气接触。此外，利用密闭传递箱对全固态锂电池复合阴极中正极活性物质与固态电解质的比例进行了无损研究，为高比能复合阴极的设计提供理论指导。

引用次数: 0