Micron最新文献

{"title":"Molecular dynamics study on the mitigation of radiation damage caused by electron pulses","authors":"Wenyan Zhao ,&nbsp;Peng Wu ,&nbsp;Rui Xu ,&nbsp;Zhuangzhi Li ,&nbsp;Huanxin Yang ,&nbsp;Chunhui Zhu ,&nbsp;Jianqi Li","doi":"10.1016/j.micron.2025.103801","DOIUrl":"10.1016/j.micron.2025.103801","url":null,"abstract":"<div><div>The reduction of radiation damage represents a long-term objective for electron microscopists, particularly those engaged in the study of biological and organic matter. Recently, electron pulses in ultrafast transmission electron microscopy have been demonstrated to serve as a damage mitigation technique for radiation-sensitive materials. Nevertheless, the underlying mechanism of the mitigation effects remains unclear. In this study, we investigate the radiation damage of graphene induced by pulsed electrons using molecular dynamics simulations within the framework of binary elastic collisions. For electron irradiation at 200 keV, it was found that the pulsed electron beam corresponds to a larger threshold angle (1.4 rad) than that for a random beam (1.0 rad). This is because two electrons can be prevented from briefly interacting with the same or a neighboring atom by the use of well-controlled electron pulses. While such a mitigation of radiation damage is only apparent near the threshold angle, and there are likely other reduction mechanisms, our results provide insight into the mitigated radiation damage of electron pulses.</div></div>","PeriodicalId":18501,"journal":{"name":"Micron","volume":"191 ","pages":"Article 103801"},"PeriodicalIF":2.5,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143403286","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}

{"title":"Structure of the trophic chamber and follicular epithelium in ovaries of the model heteropteran species Pyrrhocoris apterus","authors":"Anna Szczepankiewicz ,&nbsp;Bożena Simiczyjew","doi":"10.1016/j.micron.2025.103787","DOIUrl":"10.1016/j.micron.2025.103787","url":null,"abstract":"<div><div>The studies concern organization of the female gonads and the course of oogenesis in the model species of Heteroptera, <em>Pyrrhocoris apterus</em>. Morphological, cytochemical and ultrastructural analyses were carried out. Each of the paired ovaries of the studied bug comprises seven telotrophic ovarioles. An individual ovariole is composed of the terminal filament, tropharium, vitellarium, and ovariole pedicle. The tropharium houses morphologically diversified trophocytes. In the apical part small individual nurse cells are located, some of them are mitotically active. Below this zone nuclei of the trophocytes divide amitotically. The main part of the trophic chamber is composed of cytoplasmic lobes containing several trophocyte nuclei. Each lobe connects with the trophic core by cytoplasmic extension. In the basal part of the tropharium early previtellogenic oocytes and somatic prefollicular cells occur. The vitellarium houses oocytes at different developmental stages, surrounded by follicular cells, with younger oocytes positioned apically and older ones basally. The contact between oocytes and trophocytes is maintained by nutritive cords filled with densely packed microtubules. Numerous ribosomes and mitochondria occur within the cords. The follicular epithelium undergoes a series of changes and diversifies into three subpopulations. The general organization of <em>P. apterus</em> ovarioles is similar to that described in other representatives of Heteroptera. The differences concern the structure of the tropharium, the number and growth rate of ovarian follicles and the course of differentiation of the follicular epithelium.</div></div>","PeriodicalId":18501,"journal":{"name":"Micron","volume":"191 ","pages":"Article 103787"},"PeriodicalIF":2.5,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143419460","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}

{"title":"Effect of Y and Zr addition on the intergranular corrosion of Al-Mg alloy after sensitization treatment","authors":"Zhiqiang Ru ,&nbsp;Lili Wei ,&nbsp;Ming Liu ,&nbsp;Zhimin Pi ,&nbsp;Chang Han ,&nbsp;Ming Qiu ,&nbsp;Enbang Li ,&nbsp;Hongfeng Huang ,&nbsp;Degui Li","doi":"10.1016/j.micron.2025.103789","DOIUrl":"10.1016/j.micron.2025.103789","url":null,"abstract":"<div><div>This paper investigates the effect of adding 0.1 % Y and 0.1 % Zr microalloying on the microstructure and corrosion resistance behavior of Al-5.5Mg-0.3Mn alloys sensitization treatment. The results show that the composite addition of Y and Zr could refine the grain structure and reduce the segregation of the Mg elements during casting. Some micro-scale AlMgYZr phases could also be found in the interior region of grains. After sensitization treatment, nano-sized Al₃(Y_1-x, Zr_x) particles induce a high proportion of low-angle grain boundaries (LAGBs) in the alloy, and the AlMgYZr phase suppresses the precipitation and coarsening of β phase (Al_xMg_y) at the grain boundaries (GBs). The refinement of the β phase reduces the micro-coupling corrosion effect at GBs and improves the intergranular corrosion (IGC) resistance of the alloy. The electrochemical self-corrosion voltage of the alloy is increased, and the self-corrosion current is decreased.</div></div>","PeriodicalId":18501,"journal":{"name":"Micron","volume":"191 ","pages":"Article 103789"},"PeriodicalIF":2.5,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395337","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}

{"title":"Toward cancer detection by label-free microscopic imaging in oncological surgery: Techniques, instrumentation and applications","authors":"Roberta Galli ,&nbsp;Ortrud Uckermann","doi":"10.1016/j.micron.2025.103800","DOIUrl":"10.1016/j.micron.2025.103800","url":null,"abstract":"<div><div>This review examines the clinical application of label-free microscopy and spectroscopy, which are based on optical signals emitted by tissue components. Over the past three decades, a variety of techniques have been investigated with the aim of developing an in situ histopathology method that can rapidly and accurately identify tumor margins during surgical procedures. These techniques can be divided into two groups. One group encompasses techniques exploiting linear optical signals, and includes infrared and Raman microspectroscopy, and autofluorescence microscopy. The second group includes techniques based on nonlinear optical signals, including harmonic generation, coherent Raman scattering, and multiphoton autofluorescence microscopy. Some of these methods provide comparable information, while others are complementary. However, all of them have distinct advantages and disadvantages due to their inherent nature. The first part of the review provides an explanation of the underlying physics of the excitation mechanisms and a description of the instrumentation. It also covers endomicroscopy and data analysis, which are important for understanding the current limitations in implementing label-free techniques in clinical settings. The second part of the review describes the application of label-free microscopy imaging to improve oncological surgery with focus on brain tumors and selected gastrointestinal cancers, and provides a critical assessment of the current state of translation of these methods into clinical practice. Finally, the potential of confocal laser endomicroscopy for the acquisition of autofluorescence is discussed in the context of immediate clinical applications.</div></div>","PeriodicalId":18501,"journal":{"name":"Micron","volume":"191 ","pages":"Article 103800"},"PeriodicalIF":2.5,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143350200","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}

{"title":"Single long linear flat-top, double and triple optical beams formation by an azimuthally polarized laser light using a seven-zone BPPF system","authors":"K. Lalithambigai ,&nbsp;P.M. Anbarasan ,&nbsp;Mohd. Shkir","doi":"10.1016/j.micron.2025.103788","DOIUrl":"10.1016/j.micron.2025.103788","url":null,"abstract":"<div><div>This study explores the focusing of an azimuthally polarized laser beam with a double-ring shape as it propagates through a seven-zone Binary Phase Pupil Filtration (BPPF) system with a conventional lens, using the concept of vector diffraction. The key features of the focal region in a five-zone BPPF and a seven-zone BPPF system are analyzed and compared using mathematical findings. The commonly utilized long linear flat-top beam may be created by applying suitable angles to the seven-zone BPPF system for a conventional lens with a numerical aperture of 0.9. The intensity of the focus zones was significantly affected when the truncation parameter of the incoming polarized beams was adjusted from a lower to a higher value, generating double and triple focal ring segments. Consequently, it is a simple and novel method to adjust the spacing between focal holes, enabling the trapping of two focal segments simultaneously from the centre. This technique used in cell manipulation, molecular biology used to study the mechanical properties of DNA and proteins, and to investigate molecular motors and other biomolecules, optical engineering, optical microscopy, optical tweezers, lithography, optical micromanipulation, data storage, and beam shaping, etc.,</div></div>","PeriodicalId":18501,"journal":{"name":"Micron","volume":"191 ","pages":"Article 103788"},"PeriodicalIF":2.5,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143259429","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}

{"title":"Transmission electron microscopy analysis of Co3O4 degradation induced by electron irradiation","authors":"Jingying Sun ,&nbsp;Mei Li ,&nbsp;Hao Liu ,&nbsp;Linna Guo ,&nbsp;Xin Dong ,&nbsp;Chaolun Liang","doi":"10.1016/j.micron.2025.103786","DOIUrl":"10.1016/j.micron.2025.103786","url":null,"abstract":"<div><div>This study presents an investigation into the electron beam damage phenomenon of Co₃O₄ under transmission electron microscopy (TEM). It was found that after irradiation at a dose rate of 6.78 × 10⁶ e/nm²s, Co₃O₄ crystals exhibited surface reconstruction and faceting features. Electron energy loss spectroscopy (EELS) analysis indicates that the damage process initiates with the desorption of oxygen anions, which subsequently leads to a reduction in the valence state of cobalt cations and corresponding atomic rearrangement. High resolution TEM (HRTEM) reveals that surface faceting, which has an epitaxial relationship with the bulk, could help maintain the crystal lattice of face-centered cubic (fcc) Co₃O₄ despite Co-O bond breakage upon beam exposure. With a finely focused electron beam, the hole drilling effect was observed. The structural degradation is proposed to arise from inelastic damage that induced partial desorption of oxygen anions and rearrangement of valence-reduced cobalt cations to epitaxially grow on the surface, suggesting an interplay between irradiation damage and material restructuring. The relative phase stability of Co₃O₄, combined with its interfacial structure developed upon irradiation, are beneficial to magnetic loss and interfacial polarization loss, thereby rendering Co₃O₄ a promising candidate as an effective EMW absorber.</div></div>","PeriodicalId":18501,"journal":{"name":"Micron","volume":"190 ","pages":"Article 103786"},"PeriodicalIF":2.5,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143075076","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}

{"title":"Comparative electron diffraction analysis of strain relaxation in AlxGa1-xN materials in the microelectronics industry: 4D-STEM approach vs. TEM-based N-PED solution","authors":"Estève Drouillas ,&nbsp;Jean-Gabriel Mattei ,&nbsp;Bénédicte Warot-Fonrose","doi":"10.1016/j.micron.2025.103785","DOIUrl":"10.1016/j.micron.2025.103785","url":null,"abstract":"<div><div>Owing to its high spatial resolution and its high sensitivity to chemical element detection, transmission electron microscopy (TEM) technique enables to address high-level materials characterization of advanced technologies in the microelectronics field. TEM instruments fitted with various techniques are well-suited for assessing the local structural and chemical order of specific details. Among these techniques, 4D-STEM is suitable to estimate the strain distribution of a large field of view. This study tends to discuss the viability of using two existing commercial solutions with a low-convergence angle 4D-STEM technique and TEM-based Nanobeam Precession Electron Diffraction (N-PED) methods for strain analysis in an industrial context. In such a framework, strain measurements intend to point out the extent of defects and thus reveal a trend of the stress field, rather than to precisely estimate the absolute values of the deformations. Strain distribution maps have been obtained for AlGaN/GaN HEMT devices using two transmission electron diffraction analysis methods. The performances of 4D-STEM and Nanobeam Precession Electron Diffraction (N-PED) solution for strain mapping have been compared for both a relatively thin (≈ 55 nm) and a thick (≈ 150 nm) TEM cross section specimen. The strain maps obtained with both methods have shown comparable results for a thin sample, with the ability to characterize the deformation induced by a 1 nm-thick layer of AlN spacer grown between the AlGaN barrier and GaN channel forming the 2DEG of the HEMT device. The results presented here also illustrate the limitation of both commercial solutions in the case of a thick sample.</div></div>","PeriodicalId":18501,"journal":{"name":"Micron","volume":"190 ","pages":"Article 103785"},"PeriodicalIF":2.5,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143029086","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}

{"title":"A statistical approach for interplanar spacing metrology at a relative uncertainty below 10−4 using scanning transmission electron microscopy","authors":"Amram Azulay ,&nbsp;Itai Silber ,&nbsp;Yoram Dagan ,&nbsp;Amit Kohn","doi":"10.1016/j.micron.2025.103783","DOIUrl":"10.1016/j.micron.2025.103783","url":null,"abstract":"<div><div>Atomic-scale metrology in scanning transmission electron microscopy (STEM) allows to measure distances between individual atomic columns in crystals and is therefore an important aspect of their structural characterization. Furthermore, it allows to locally resolve strain in crystals and to calibrate precisely the pixel size in STEM. We present a method dedicated to the evaluation of interplanar spacing (d-spacing) based on an algorithm including curve fitting of processed high-angle annular dark-field STEM (HAADF STEM) signals. By examining simulated data of perovskite cubic SrTiO₃, we confirm that our proposed method is unbiased, and the precision is better than the significant digit of the input value. Then, we study experimental data to learn how electron dose, sampling resolution, and statistical sampling affect the mean and precision values of <em>d</em>₁₁₀. For single d-spacing measurements using a probe corrected STEM, we find that uncertainty ranges between 1 and 3 pm. Here, we measure numerous d-spacings in an automated and statistical approach, resulting in relative uncertainties in mean values ≤ 10⁻⁴. Thus, we propose to calibrate TEMs using this method as it enables measuring lattice parameters at uncertainties comparable to reports of x-ray diffraction measurements, but with a significantly lower sample volume, in this case ∼ 10⁻³ µm³.</div></div>","PeriodicalId":18501,"journal":{"name":"Micron","volume":"190 ","pages":"Article 103783"},"PeriodicalIF":2.5,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143008268","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}

{"title":"Grids designed for tomography: Stereovision transmission electron microscopy makes it easy to determine the winding handedness of helical nanocoils","authors":"Noriyuki Ishii ,&nbsp;Yoshikatsu Ogawa","doi":"10.1016/j.micron.2025.103784","DOIUrl":"10.1016/j.micron.2025.103784","url":null,"abstract":"<div><div>Determining the handedness of helical nanocoils using transmission electron microscopy (TEM) has traditionally been challenging due to the deep depth of field and transmission nature of TEM, complementary techniques are considered necessary and have been practiced such as low angle rotary shadowing, scanning electron microscopy (SEM), or atomic force microscopy (AFM). These methods require customized sample preparation, making direct comparison difficult. Inspired by the need to identify the helical winding direction from TEM images alone, we developed a specialized tomography grid to capture stereo-pair images, enabling stereopsis. By leveraging previous research on nano-coiled structures using identical materials and tomography grids, we successfully identified the handedness of helical coils. Our model sample consisted of graphitic nanotubes with bilayer ribbons of π-stacked hexa-<em>peri</em>-hexabenzocoronene (HBC) units, forming right- and left-handed helical coils from (S)- and (R)-enantiomers of the amphiphile [Jin W. et al. (2005) Proc. Natl. Acad. Sci. U.S.A. 102, 10801–10806]. Using stereo-pair TEM images, we evaluated the accuracy of our approach in visually determining the handedness of helical coils. The technique provides a valuable tool for sample inspection, screening, and assessing relative positions, including the determination of helical handedness.</div></div>","PeriodicalId":18501,"journal":{"name":"Micron","volume":"190 ","pages":"Article 103784"},"PeriodicalIF":2.5,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142983956","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}

{"title":"Development of an accurate simplified approach for data processing in AFM indentation experiments","authors":"S.V. Kontomaris ,&nbsp;A. Malamou ,&nbsp;A. Stylianou","doi":"10.1016/j.micron.2024.103782","DOIUrl":"10.1016/j.micron.2024.103782","url":null,"abstract":"<div><div>Atomic Force Microscopy (AFM) nanoindentation is the most effective method for determining the mechanical properties of soft biological materials and biomaterials at the nanoscale, with significant applications in many areas, including cancer diagnosis. However, a major drawback of this method is the complexity of the experimental procedure and data processing, which requires several calibration steps.To avoid this complexity, the AFM tip is usually approximated as a perfect cone. In this case, <span><math><mrow><mi>F</mi><mo>=</mo><mi>c</mi><msup><mrow><mi>h</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></math></span>, where <em>F</em> is the applied force, ℎ is the indentation depth, and <span><math><mi>c</mi></math></span> is a constant that depends on both the cone’s half-angle and the material's properties. However, since AFM tips are pyramidal with a rounded tip apex (or similar to a truncated cone in some cases), the conical approximation may lead to non-negligible errors. Although equations exist that relate the applied force, indentation depth, and the sample’s Young’s modulus for real indenters, they are rarely used because they do not directly relate the applied force to the indentation depth (i.e., the fitting process is much more complicated compared to the conical approximation). In this paper, a new, accurate, simplified approach for data processing is proposed, based on fitting the force–indentation data to a quadratic equation of the form: <span><math><mrow><mi>F</mi><mo>=</mo><msub><mrow><mi>c</mi></mrow><mrow><mn>2</mn></mrow></msub><msup><mrow><mi>h</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>+</mo><msub><mrow><mi>c</mi></mrow><mrow><mn>1</mn></mrow></msub><mi>h</mi></mrow></math></span>. It is proven that the parameter <span><math><msub><mrow><mi>c</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span> is independent of the tip apex properties. On the other hand, the parameter <span><math><msub><mrow><mi>c</mi></mrow><mrow><mn>1</mn></mrow></msub></math></span> depends on the material properties, the cone’s half angle, and the shape and dimensions of the tip apex. Simulated force-indentation data from sphero-conical and blunted pyramidal indenters, along with real experimental data from lung tissues, are processed using the proposed approach. The key result is that Young’s modulus can be accurately determined using only the <span><math><msub><mrow><mi>c</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span> parameter; therefore, tip characterization can be avoided.</div></div>","PeriodicalId":18501,"journal":{"name":"Micron","volume":"190 ","pages":"Article 103782"},"PeriodicalIF":2.5,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142971558","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}