Pub Date : 2026-02-02DOI: 10.1016/j.micron.2026.104002
A S Prikhodko, N I Borgardt
Fine-tuning the interlayer distance in bilayer graphene (BLG) is essential for advancing novel devices that utilize graphenes' exceptional properties. Thus, the precise measurement of interlayer distances with sub-angstrom accuracy in BLG is important. In this study, we develop an approach that focuses on local interlayer spacing measurements and employs further statistical analysis to achieve a sub-angstrom accuracy of the obtained mean distance value. The proposed approach utilizes high-resolution transmission electron microscopy (HRTEM) data combined with the exit wave reconstruction technique. As a result, it allows for the extraction of an exit wave phase map that is free from the delocalization effect and contains structural information at the atomic scale. The effectiveness of the developed approach was validated through testing on atomistic 6H-SiC/BLG structures, found via molecular dynamics simulations. The mean interlayer distance d measured using the phase map calculated for the test structure closely matched the interlayer distance obtained from direct atomic positions. The application of the distance measurement approach to the experimental exit wave phase map, yielded d=(0.351 ± 0.018) nm. The utilization of two slightly over-focused micrographs demonstrated d=(0.355 ± 0.027) nm and d=(0.359 ± 0.027) nm. Due to the delocalization effect, these values were somewhat larger than the value from the reconstructed exit wave phase map. If extremely high accuracy of the d measurement is not needed, it is sufficient to use a slightly over-focused image, leading to a mismatch value of ≈2%. Overall, the developed approach for measuring interlayer distances in BLG is essential for exploring the correlation between d in van der Waals 2D materials and their properties.
微调双层石墨烯（BLG）的层间距离对于开发利用石墨烯特殊性能的新型器件至关重要。因此，以亚埃的精度精确测量层间距离在BLG中是非常重要的。在本研究中，我们开发了一种专注于局部层间间距测量的方法，并采用进一步的统计分析来实现所获得的平均距离值的亚埃精度。该方法利用高分辨率透射电子显微镜（HRTEM）数据结合出口波重建技术。因此，它允许提取不受离域效应影响的出口波相位图，并包含原子尺度的结构信息。通过分子动力学模拟对原子6H-SiC/BLG结构进行测试，验证了所开发方法的有效性。用测试结构计算的相图测量的平均层间距离d与直接从原子位置得到的层间距离密切匹配。利用距离测量法对实验出口波相位图进行测量，得到d=(0.351±0.018)nm，利用两张稍微过聚焦的显微照片得到d=(0.355±0.027)nm和d=(0.359±0.027)nm，由于离域效应，这两个值略大于重建出口波相位图的值。如果不需要极高的d测量精度，使用稍微过焦的图像就足够了，导致失配值≈2%。总的来说，开发的测量BLG层间距离的方法对于探索d in van der Waals二维材料及其性质之间的相关性至关重要。
{"title":"Accurate interlayer distance measurement in bilayer graphene on SiC by high-resolution electron microscopy data analysis.","authors":"A S Prikhodko, N I Borgardt","doi":"10.1016/j.micron.2026.104002","DOIUrl":"https://doi.org/10.1016/j.micron.2026.104002","url":null,"abstract":"<p><p>Fine-tuning the interlayer distance in bilayer graphene (BLG) is essential for advancing novel devices that utilize graphenes' exceptional properties. Thus, the precise measurement of interlayer distances with sub-angstrom accuracy in BLG is important. In this study, we develop an approach that focuses on local interlayer spacing measurements and employs further statistical analysis to achieve a sub-angstrom accuracy of the obtained mean distance value. The proposed approach utilizes high-resolution transmission electron microscopy (HRTEM) data combined with the exit wave reconstruction technique. As a result, it allows for the extraction of an exit wave phase map that is free from the delocalization effect and contains structural information at the atomic scale. The effectiveness of the developed approach was validated through testing on atomistic 6H-SiC/BLG structures, found via molecular dynamics simulations. The mean interlayer distance d measured using the phase map calculated for the test structure closely matched the interlayer distance obtained from direct atomic positions. The application of the distance measurement approach to the experimental exit wave phase map, yielded d=(0.351 ± 0.018) nm. The utilization of two slightly over-focused micrographs demonstrated d=(0.355 ± 0.027) nm and d=(0.359 ± 0.027) nm. Due to the delocalization effect, these values were somewhat larger than the value from the reconstructed exit wave phase map. If extremely high accuracy of the d measurement is not needed, it is sufficient to use a slightly over-focused image, leading to a mismatch value of ≈2%. Overall, the developed approach for measuring interlayer distances in BLG is essential for exploring the correlation between d in van der Waals 2D materials and their properties.</p>","PeriodicalId":18501,"journal":{"name":"Micron","volume":"203 ","pages":"104002"},"PeriodicalIF":2.2,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146137691","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}
Pub Date : 2026-01-31DOI: 10.1016/j.micron.2026.103999
Hui-Xin Tan, Qiong-Hua Gao, Xin Tong
Male accessory glands of insects serve as secretory organs, exhibiting the ability to produce secretions that regulate reproductive processes. Their histology and ultrastructure are generally regarded as being diverse within insect groups, however, as one of the largest groups of insects, the ultrastructure of male accessory glands in Cerambycidae has never received sufficient attention. The longhorn beetle Glenea cantor (Fabricius, 1787) (Coleoptera: Cerambycidae: Lamiinae) is a wood-boring pest infesting urban landscape trees in southern China, significantly compromising urban greening. In this study, light and transmission electron microscopes were used to reveal the histological and ultrastructural characteristics of the male accessory glands of G. cantor. Results show that the males of G. cantor possess two pairs of morphologically distinct mesodermal glands (mesadenia). One pair exhibits an overall elongated tubular shape, while the other displays a tightly coiled, clew-like structure proximally and free-ending tubular regions distally. Ultrastructurally, both pairs of mesadenia exhibit identical cell types, with abundant secretory granules observed within the cytoplasm and lumen. Each gland possesses a muscular layer, an epithelium, and a lumen. The epithelial cell layer contains cellular structures and organelles indicative of active protein synthesis, including rough endoplasmic reticulum (RER), mitochondria, Golgi appartus, and secretory vesicles. This epithelium is also characterized by the presence of microvilli. The lumen is filled with electron-dense secretion. Notably, distinct morphological and ultrastructural differences exist both between the two mesadenial pairs and within each pair between their proximal and distal regions. This study provides the first comparative morphological and ultrastructural analysis of regional differentiation in two pairs of male accessory glands of G. cantor, revealing adaptive changes acquired during their evolution.
{"title":"The morphology of male accessory glands in the Glenea cantor (Fabricius, 1787) (Coleoptera: Cerambycidae: Lamiinae).","authors":"Hui-Xin Tan, Qiong-Hua Gao, Xin Tong","doi":"10.1016/j.micron.2026.103999","DOIUrl":"https://doi.org/10.1016/j.micron.2026.103999","url":null,"abstract":"<p><p>Male accessory glands of insects serve as secretory organs, exhibiting the ability to produce secretions that regulate reproductive processes. Their histology and ultrastructure are generally regarded as being diverse within insect groups, however, as one of the largest groups of insects, the ultrastructure of male accessory glands in Cerambycidae has never received sufficient attention. The longhorn beetle Glenea cantor (Fabricius, 1787) (Coleoptera: Cerambycidae: Lamiinae) is a wood-boring pest infesting urban landscape trees in southern China, significantly compromising urban greening. In this study, light and transmission electron microscopes were used to reveal the histological and ultrastructural characteristics of the male accessory glands of G. cantor. Results show that the males of G. cantor possess two pairs of morphologically distinct mesodermal glands (mesadenia). One pair exhibits an overall elongated tubular shape, while the other displays a tightly coiled, clew-like structure proximally and free-ending tubular regions distally. Ultrastructurally, both pairs of mesadenia exhibit identical cell types, with abundant secretory granules observed within the cytoplasm and lumen. Each gland possesses a muscular layer, an epithelium, and a lumen. The epithelial cell layer contains cellular structures and organelles indicative of active protein synthesis, including rough endoplasmic reticulum (RER), mitochondria, Golgi appartus, and secretory vesicles. This epithelium is also characterized by the presence of microvilli. The lumen is filled with electron-dense secretion. Notably, distinct morphological and ultrastructural differences exist both between the two mesadenial pairs and within each pair between their proximal and distal regions. This study provides the first comparative morphological and ultrastructural analysis of regional differentiation in two pairs of male accessory glands of G. cantor, revealing adaptive changes acquired during their evolution.</p>","PeriodicalId":18501,"journal":{"name":"Micron","volume":"203 ","pages":"103999"},"PeriodicalIF":2.2,"publicationDate":"2026-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146113614","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}
Pub Date : 2026-01-30DOI: 10.1016/j.micron.2026.104000
Boualem Rai , Ismail Bencherifa , Denis Solas , François Brisset , Thierry Baudin , Hiba Azzeddine
The hot-rolled Mg-0.6Gd (wt%) alloy at 723 K for 85 % thickness reduction was subjected to annealing treatments at a temperature range of 573–723 K for durations ranging from 5 to 1440 min to study the microstructure evolution. In addition, the recrystallization and grain growth kinetics were evaluated using Vickers microhardness and mean grain size variation, respectively. The deformed microstructure characterized by the fragmentation of coarse initial grains and a high number of twins was retained after annealing at 573 and 623 K. In contrast, a microstructure with equiaxed recrystallized grains developed rapidly during annealing at 673 and 723 K. The mean grain size increased with both annealing temperature and time, reaching values of 11.8 ± 1.3, 21.1 ± 2.2, 36.1 ± 1.4, 48.9 ± 2.5 µm after 1440 min at 573, 623, 673 and 723 K, respectively. Hot-rolling and heat treatments altered the nature of the existing second-phase particles, which controlled the obtained microstructures via solute drag and the Zener pinning effect. Based on the Johnson-Mehl-Avrami Kolmogorov model, the recrystallization activation energy was 107.1 ± 14.1 kJ/mol, suggesting that the grain boundary diffusion controlled the static recrystallization. Grain growth behaviour was distinguished into two temperature regimes: from 573 to 623 K and from 623 to 723 K. At the 573–623 K range, the grain growth was restricted and the obtained activation energy of 200 kJ/mol evidenced the control of lattice self-diffusion. At the 623–723 K range, the activation energy decreased significantly to 50.1 ± 5.5 kJ/mol, indicating enhanced grain growth.
{"title":"Microstructure evolution and kinetics of recrystallization and grain growth of hot-rolled Mg-Gd alloy","authors":"Boualem Rai , Ismail Bencherifa , Denis Solas , François Brisset , Thierry Baudin , Hiba Azzeddine","doi":"10.1016/j.micron.2026.104000","DOIUrl":"10.1016/j.micron.2026.104000","url":null,"abstract":"<div><div>The hot-rolled Mg-0.6Gd (wt%) alloy at 723 K for 85 % thickness reduction was subjected to annealing treatments at a temperature range of 573–723 K for durations ranging from 5 to 1440 min to study the microstructure evolution. In addition, the recrystallization and grain growth kinetics were evaluated using Vickers microhardness and mean grain size variation, respectively. The deformed microstructure characterized by the fragmentation of coarse initial grains and a high number of twins was retained after annealing at 573 and 623 K. In contrast, a microstructure with equiaxed recrystallized grains developed rapidly during annealing at 673 and 723 K. The mean grain size increased with both annealing temperature and time, reaching values of 11.8 ± 1.3, 21.1 ± 2.2, 36.1 ± 1.4, 48.9 ± 2.5 µm after 1440 min at 573, 623, 673 and 723 K, respectively. Hot-rolling and heat treatments altered the nature of the existing second-phase particles, which controlled the obtained microstructures via solute drag and the Zener pinning effect. Based on the Johnson-Mehl-Avrami Kolmogorov model, the recrystallization activation energy was 107.1 ± 14.1 kJ/mol, suggesting that the grain boundary diffusion controlled the static recrystallization. Grain growth behaviour was distinguished into two temperature regimes: from 573 to 623 K and from 623 to 723 K. At the 573–623 K range, the grain growth was restricted and the obtained activation energy of 200 kJ/mol evidenced the control of lattice self-diffusion. At the 623–723 K range, the activation energy decreased significantly to 50.1 ± 5.5 kJ/mol, indicating enhanced grain growth.</div></div>","PeriodicalId":18501,"journal":{"name":"Micron","volume":"203 ","pages":"Article 104000"},"PeriodicalIF":2.2,"publicationDate":"2026-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146078347","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}
Pub Date : 2026-01-29DOI: 10.1016/j.micron.2026.103998
M. Herrera , J. Pizarro , M. Paz Guerrero , G. Bárcenas , E. Milán , A. Speghini , S.I. Molina
Accurate three-dimensional (3D) localization of rare-earth dopants in crystalline phosphor nanoparticles (NPs) remains a critical challenge for understanding structure-property relationships and optimizing luminescent performance. Through-focus High-Angle Annular Dark-Field Scanning Transmission Electron Microscopy (HAADF-STEM) offers promising depth sectioning for bulk materials, but its systematic application to beam-sensitive NPs is unexplored. We investigate through-focus HAADF-STEM feasibility for 3D dopant distributions in SrF₂:Eu NPs via a comprehensive simulation-to-experiment approach, addressing complex channeling effects. Multislice simulations reveal that electron channeling along Sr atomic columns significantly broadens the electron probe and introduces systematic positioning errors at greater depths. A developed depth correction function accounts for channeling effects, achieving high localization accuracy for individual Eu atoms in simulated focal series. Critical spatial resolution limits for multiple dopant detection have been established, as individual dopants become indistinguishable due to overlapping channeling effects. Experimental implementation has revealed fundamental practical constraints limiting through-focus analysis of SrF₂:Eu NPs. Beam damage and specimen instability (such as rigid-body motion or beam-induced atomic displacement), pronounced in NPs, critically compromise localization precision. Despite unachieved 3D dopant characterization for these NPs, this investigation establishes quantitative frameworks for understanding through-focus HAADF-STEM capabilities and limitations in beam-sensitive crystalline systems. Developed correction methodologies guide future implementations in more stable materials, while systematic characterization of damage and stability defines realistic boundaries for NP depth sectioning.
{"title":"Exploring the limits of 3D dopant localization in phosphor nanoparticles: A simulation-to-experiment perspective via through-focus HAADF-STEM","authors":"M. Herrera , J. Pizarro , M. Paz Guerrero , G. Bárcenas , E. Milán , A. Speghini , S.I. Molina","doi":"10.1016/j.micron.2026.103998","DOIUrl":"10.1016/j.micron.2026.103998","url":null,"abstract":"<div><div>Accurate three-dimensional (3D) localization of rare-earth dopants in crystalline phosphor nanoparticles (NPs) remains a critical challenge for understanding structure-property relationships and optimizing luminescent performance. Through-focus High-Angle Annular Dark-Field Scanning Transmission Electron Microscopy (HAADF-STEM) offers promising depth sectioning for bulk materials, but its systematic application to beam-sensitive NPs is unexplored. We investigate through-focus HAADF-STEM feasibility for 3D dopant distributions in SrF₂:Eu NPs via a comprehensive simulation-to-experiment approach, addressing complex channeling effects. Multislice simulations reveal that electron channeling along Sr atomic columns significantly broadens the electron probe and introduces systematic positioning errors at greater depths. A developed depth correction function accounts for channeling effects, achieving high localization accuracy for individual Eu atoms in simulated focal series. Critical spatial resolution limits for multiple dopant detection have been established, as individual dopants become indistinguishable due to overlapping channeling effects. Experimental implementation has revealed fundamental practical constraints limiting through-focus analysis of SrF₂:Eu NPs. Beam damage and specimen instability (such as rigid-body motion or beam-induced atomic displacement), pronounced in NPs, critically compromise localization precision. Despite unachieved 3D dopant characterization for these NPs, this investigation establishes quantitative frameworks for understanding through-focus HAADF-STEM capabilities and limitations in beam-sensitive crystalline systems. Developed correction methodologies guide future implementations in more stable materials, while systematic characterization of damage and stability defines realistic boundaries for NP depth sectioning.</div></div>","PeriodicalId":18501,"journal":{"name":"Micron","volume":"203 ","pages":"Article 103998"},"PeriodicalIF":2.2,"publicationDate":"2026-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146078242","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}
Pub Date : 2026-01-20DOI: 10.1016/j.micron.2026.103997
Daniela Predoi , Simona Liliana Iconaru , Steluţa Carmen Ciobanu , Krzysztof Rokosz , Steinar Raaen , Damien Leduc , Mounsif Ech Cherif El Kettani , Philippe Zelmar , Coralia Bleotu , Mihai-Valentin Predoi , Ştefan Ţălu
The present study, presents for the first time the development and characterization of innovative bioceramic samples based on magnesium doped hydroxyapatite (xMg = 0.015 and xMg = 0.05) obtained by a modified co-precipitation method and the lyophilization of the final precipitate (1.5MgHAp-LF and 5MgHAp-LF). The lyophilized powders were thoroughly investigated, obtaining valuable information regarding stability through non-destructive ultrasound measurements, structure, chemical composition, bonding states, surface properties and biological evaluations. The X-ray diffraction (XRD) patterns of the samples revealed peaks characteristic of pure hexagonal hydroxyapatite (P63/m). When calcium ions were substituted with magnesium ions, a reduction in peak intensity and a slight broadening of the peaks were observed as the magnesium concentration increased. Fourier transform infrared spectroscopy (FTIR) was used to investigate the structural and compositional characteristics of the studied samples. Information regarding the surface topography of 1.5MgHAp-LF and 5MgHAp-LF pellets was obtained using scanning electron microcopy (SEM) and atomic force microscopy (AFM) studies. Additionally, AFM topographies and SEM images provided useful insights into the roughness of the samples. A complementary analysis was performed on a larger surface area using a Scanning Acoustic Microscope (SAM). The biological performance of 1.5MgHAp-LF and 5MgHAp-LF pellets was evaluated using the MG63 osteoblast-like cell line. Surface analyses—including furrow morphology, texture orientation, fractal dimensionality, and frequency spectrum—revealed that increased magnesium content induces greater topographical order and complexity, enhancing the material’s potential for osteoconductive applications. The cytotoxicity of the pellets was assessed by determining the cell viability through the MTT assay after an incubation period of 24 h. Also, fluorescence microscopy (FM) visualization was used to determine the cytotoxicity of the pellets. The results demonstrated that both 1.5MgHApLF and 5MgHApLF pellets exhibited good biocompatibility for both tested samples. Furthermore, the interaction of the MG63 cells with the surface of the 1.5MgHAp-LF and 5MgHAp-LF pellets was assessed by metallographic microscopy (MM) and atomic force microscopy (AFM). MM and AFM analyses revealed that the surface morphology of both materials effectively supported cellular attachment and growth. These findings suggest that both 1.5MgHAp-LF and 5MgHAp-LF pellets have a significant potential for being used in the development of advanced biomaterials for biomedical use.
{"title":"Freeze-dried magnesium doped hydroxyapatite for biomedical applications","authors":"Daniela Predoi , Simona Liliana Iconaru , Steluţa Carmen Ciobanu , Krzysztof Rokosz , Steinar Raaen , Damien Leduc , Mounsif Ech Cherif El Kettani , Philippe Zelmar , Coralia Bleotu , Mihai-Valentin Predoi , Ştefan Ţălu","doi":"10.1016/j.micron.2026.103997","DOIUrl":"10.1016/j.micron.2026.103997","url":null,"abstract":"<div><div>The present study, presents for the first time the development and characterization of innovative bioceramic samples based on magnesium doped hydroxyapatite (x<sub>Mg</sub> = 0.015 and x<sub>Mg</sub> = 0.05) obtained by a modified co-precipitation method and the lyophilization of the final precipitate (1.5MgHAp-LF and 5MgHAp-LF). The lyophilized powders were thoroughly investigated, obtaining valuable information regarding stability through non-destructive ultrasound measurements, structure, chemical composition, bonding states, surface properties and biological evaluations. The X-ray diffraction (XRD) patterns of the samples revealed peaks characteristic of pure hexagonal hydroxyapatite (P63/m). When calcium ions were substituted with magnesium ions, a reduction in peak intensity and a slight broadening of the peaks were observed as the magnesium concentration increased. Fourier transform infrared spectroscopy (FTIR) was used to investigate the structural and compositional characteristics of the studied samples. Information regarding the surface topography of 1.5MgHAp-LF and 5MgHAp-LF pellets was obtained using scanning electron microcopy (SEM) and atomic force microscopy (AFM) studies. Additionally, AFM topographies and SEM images provided useful insights into the roughness of the samples. A complementary analysis was performed on a larger surface area using a Scanning Acoustic Microscope (SAM). The biological performance of 1.5MgHAp-LF and 5MgHAp-LF pellets was evaluated using the MG63 osteoblast-like cell line. Surface analyses—including furrow morphology, texture orientation, fractal dimensionality, and frequency spectrum—revealed that increased magnesium content induces greater topographical order and complexity, enhancing the material’s potential for osteoconductive applications. The cytotoxicity of the pellets was assessed by determining the cell viability through the MTT assay after an incubation period of 24 h. Also, fluorescence microscopy (FM) visualization was used to determine the cytotoxicity of the pellets. The results demonstrated that both 1.5MgHApLF and 5MgHApLF pellets exhibited good biocompatibility for both tested samples. Furthermore, the interaction of the MG63 cells with the surface of the 1.5MgHAp-LF and 5MgHAp-LF pellets was assessed by metallographic microscopy (MM) and atomic force microscopy (AFM). MM and AFM analyses revealed that the surface morphology of both materials effectively supported cellular attachment and growth. These findings suggest that both 1.5MgHAp-LF and 5MgHAp-LF pellets have a significant potential for being used in the development of advanced biomaterials for biomedical use.</div></div>","PeriodicalId":18501,"journal":{"name":"Micron","volume":"203 ","pages":"Article 103997"},"PeriodicalIF":2.2,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024183","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}
Pub Date : 2026-01-17DOI: 10.1016/j.micron.2026.103994
Runqi Yan , Yonggui Zhai , Hongguang Wang , Yongdong Li , Meng Cao
This study develops a Monte Carlo simulation framework for secondary electron emission, leveraging first-principles-derived energy loss functions to model inelastic scattering processes. The simulation incorporates distinct energy-loss mechanisms associated with different excitation regions in the momentum-energy plane. Furthermore, an experimentally parameterized surface excitation probability is integrated to differentiate between surface and bulk scattering events. By applying this model to TixNy compounds, the work clarifies how the differential inelastic scattering cross section governs the stoichiometry-dependent variation of secondary electron yields in TixNy systems.
{"title":"Monte Carlo simulation of secondary electron emission in TixNy based on first principle calculation","authors":"Runqi Yan , Yonggui Zhai , Hongguang Wang , Yongdong Li , Meng Cao","doi":"10.1016/j.micron.2026.103994","DOIUrl":"10.1016/j.micron.2026.103994","url":null,"abstract":"<div><div>This study develops a Monte Carlo simulation framework for secondary electron emission, leveraging first-principles-derived energy loss functions to model inelastic scattering processes. The simulation incorporates distinct energy-loss mechanisms associated with different excitation regions in the momentum-energy plane. Furthermore, an experimentally parameterized surface excitation probability is integrated to differentiate between surface and bulk scattering events. By applying this model to Ti<sub>x</sub>N<sub>y</sub> compounds, the work clarifies how the differential inelastic scattering cross section governs the stoichiometry-dependent variation of secondary electron yields in Ti<sub>x</sub>N<sub>y</sub> systems.</div></div>","PeriodicalId":18501,"journal":{"name":"Micron","volume":"203 ","pages":"Article 103994"},"PeriodicalIF":2.2,"publicationDate":"2026-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146023836","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}
Pub Date : 2026-01-14DOI: 10.1016/j.micron.2026.103995
Bo Zhu , Entuo Liu , Wei Long , Lingxi Hu , Shang Zhou , Shixin Ye-Lehmann , Linhua Jiang , Yao-Wang Li
Cryo-electron microscopy (cryo-EM) has become an essential technique for resolving the three-dimensional structures of biological macromolecules, where accurate particle picking is a critical prerequisite for high-resolution reconstruction. Despite recent advances with convolutional neural networks (CNNs) and Transformer-based models, existing automated methods often encounter difficulties under low signal-to-noise ratio (SNR) conditions and heterogeneous backgrounds. CNNs are constrained in capturing long-range dependencies, whereas Transformers, although effective in modeling global context, tend to underperform in preserving fine structural details and require substantial computational resources. Here, we present VMPicker, a framework integrating Vision Mamba and the Segment Anything Model (SAM). At its core is CryoVMUNet, which extends the standard U-Net by incorporating high-order visual state space (H-VSS) modules alongside convolutional operations and attention mechanisms. This design enables the simultaneous extraction of global dependencies and fine-grained local features while reducing redundant information. By combining CryoVMUNet’s high-fidelity predictions with SAM-based automated segmentation, VMPicker achieves precise and robust identification of protein particles in complex cryo-EM micrographs. Benchmarking on ten publicly available cryo-EM datasets shows that VMPicker consistently outperforms state-of-the-art approaches, achieving average improvements of 8.1 % in Precision, 11.2 % in F1 score, and 12.3 % in Dice coefficient, while maintaining competitive Recall. It also produces the highest and most consistent reconstructed density map resolutions across multiple CryoPPP datasets, demonstrating its ability to generate high-quality 3D structures. Furthermore, VMPicker delivers higher computational efficiency with a more compact model design. To our knowledge, this study represents the first application of Vision Mamba to cryo-EM image analysis, underscoring its potential to advance reliable particle picking across diverse experimental conditions.
{"title":"VMPicker: A novel cryo-EM particle picker leveraging vision mamba and the segment anything model","authors":"Bo Zhu , Entuo Liu , Wei Long , Lingxi Hu , Shang Zhou , Shixin Ye-Lehmann , Linhua Jiang , Yao-Wang Li","doi":"10.1016/j.micron.2026.103995","DOIUrl":"10.1016/j.micron.2026.103995","url":null,"abstract":"<div><div>Cryo-electron microscopy (cryo-EM) has become an essential technique for resolving the three-dimensional structures of biological macromolecules, where accurate particle picking is a critical prerequisite for high-resolution reconstruction. Despite recent advances with convolutional neural networks (CNNs) and Transformer-based models, existing automated methods often encounter difficulties under low signal-to-noise ratio (SNR) conditions and heterogeneous backgrounds. CNNs are constrained in capturing long-range dependencies, whereas Transformers, although effective in modeling global context, tend to underperform in preserving fine structural details and require substantial computational resources. Here, we present VMPicker, a framework integrating Vision Mamba and the Segment Anything Model (SAM). At its core is CryoVMUNet, which extends the standard U-Net by incorporating high-order visual state space (H-VSS) modules alongside convolutional operations and attention mechanisms. This design enables the simultaneous extraction of global dependencies and fine-grained local features while reducing redundant information. By combining CryoVMUNet’s high-fidelity predictions with SAM-based automated segmentation, VMPicker achieves precise and robust identification of protein particles in complex cryo-EM micrographs. Benchmarking on ten publicly available cryo-EM datasets shows that VMPicker consistently outperforms state-of-the-art approaches, achieving average improvements of 8.1 % in Precision, 11.2 % in F1 score, and 12.3 % in Dice coefficient, while maintaining competitive Recall. It also produces the highest and most consistent reconstructed density map resolutions across multiple CryoPPP datasets, demonstrating its ability to generate high-quality 3D structures. Furthermore, VMPicker delivers higher computational efficiency with a more compact model design. To our knowledge, this study represents the first application of Vision Mamba to cryo-EM image analysis, underscoring its potential to advance reliable particle picking across diverse experimental conditions.</div></div>","PeriodicalId":18501,"journal":{"name":"Micron","volume":"203 ","pages":"Article 103995"},"PeriodicalIF":2.2,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145979334","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}
Pub Date : 2026-01-14DOI: 10.1016/j.micron.2026.103996
Toshihiko Ogura, Tomoko Okada
Optical microscopes are essential equipment for observing and analysing cultured cells. In observations using a normal optical microscope, as the contrast of cells is rather low, phase contrast and differential interference microscopes are commonly used. In some cases, specific proteins in cells are fluorescently labelled and observed using a fluorescence microscope. In such observations, cells are generally cultured on a glass surface and observed through the glass. Therefore, spherical aberration occurs due to the refraction of light on the glass surface. This spherical aberration becomes larger when using an objective lens with higher magnification and higher numerical aperture, resulting in a decrease of spatial resolution and contrast. Here, we found that by observing cells cultured on an extremely thin silicon nitride (SiN) film (50 nm thick) under a conventional optical microscope, we could directly observe the cells at high resolution without spherical aberration. This improvement of spatial resolution was confirmed with both inverted and upright optical microscopes. Using a normal 100 × objective lens without oil immersion, we were able to directly observe melanosomes in melanoma cells and analyse their dynamic movement. We believe that using our original sample holder with thin SiN film will make it easy to observe live cells at high resolution and that this method will contribute to a wide range of biological research.
{"title":"High-resolution observation of live cells on silicon nitride film using a conventional optical microscope","authors":"Toshihiko Ogura, Tomoko Okada","doi":"10.1016/j.micron.2026.103996","DOIUrl":"10.1016/j.micron.2026.103996","url":null,"abstract":"<div><div>Optical microscopes are essential equipment for observing and analysing cultured cells. In observations using a normal optical microscope, as the contrast of cells is rather low, phase contrast and differential interference microscopes are commonly used. In some cases, specific proteins in cells are fluorescently labelled and observed using a fluorescence microscope. In such observations, cells are generally cultured on a glass surface and observed through the glass. Therefore, spherical aberration occurs due to the refraction of light on the glass surface. This spherical aberration becomes larger when using an objective lens with higher magnification and higher numerical aperture, resulting in a decrease of spatial resolution and contrast. Here, we found that by observing cells cultured on an extremely thin silicon nitride (SiN) film (50 nm thick) under a conventional optical microscope, we could directly observe the cells at high resolution without spherical aberration. This improvement of spatial resolution was confirmed with both inverted and upright optical microscopes. Using a normal 100 × objective lens without oil immersion, we were able to directly observe melanosomes in melanoma cells and analyse their dynamic movement. We believe that using our original sample holder with thin SiN film will make it easy to observe live cells at high resolution and that this method will contribute to a wide range of biological research.</div></div>","PeriodicalId":18501,"journal":{"name":"Micron","volume":"203 ","pages":"Article 103996"},"PeriodicalIF":2.2,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145998472","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}
Pub Date : 2026-01-02DOI: 10.1016/j.micron.2025.103984
Mitchell Mika, Paul McIntyre, Mary Sevart, Megan E. Hurley, Victoria M. Miller, Assel Aitkaliyeva
Measuring the volume fraction of a constituent is a frequent requirement for materials characterization. One method for doing so is measuring the area fraction of the constituent captured in digital micrographs as an approximation of the volume fraction. Area fraction measurements are often automated using computer algorithms. These algorithms can be sensitive to imaging conditions, such as the feature-background contrast, which can introduce significant uncertainty into reported values. In this work, we developed a point-counting algorithm that can measure area fraction to a user-specified degree of precision, ensuring an efficient sample size selection based on the needs of the characterization effort. The algorithm is then implemented into an open-source software, Robust Area Fraction Tool (RAFT), that facilitates sample size calculation and point-counting. Performance of the algorithm was quantified on both simulated and real digital micrographs, and the results showed the algorithm met or exceeded desired precision values in almost all test cases.
{"title":"RAFT: A program for area fraction measurement of digital micrographs","authors":"Mitchell Mika, Paul McIntyre, Mary Sevart, Megan E. Hurley, Victoria M. Miller, Assel Aitkaliyeva","doi":"10.1016/j.micron.2025.103984","DOIUrl":"10.1016/j.micron.2025.103984","url":null,"abstract":"<div><div>Measuring the volume fraction of a constituent is a frequent requirement for materials characterization. One method for doing so is measuring the area fraction of the constituent captured in digital micrographs as an approximation of the volume fraction. Area fraction measurements are often automated using computer algorithms. These algorithms can be sensitive to imaging conditions, such as the feature-background contrast, which can introduce significant uncertainty into reported values. In this work, we developed a point-counting algorithm that can measure area fraction to a user-specified degree of precision, ensuring an efficient sample size selection based on the needs of the characterization effort. The algorithm is then implemented into an open-source software, Robust Area Fraction Tool (RAFT), that facilitates sample size calculation and point-counting. Performance of the algorithm was quantified on both simulated and real digital micrographs, and the results showed the algorithm met or exceeded desired precision values in almost all test cases.</div></div>","PeriodicalId":18501,"journal":{"name":"Micron","volume":"203 ","pages":"Article 103984"},"PeriodicalIF":2.2,"publicationDate":"2026-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145897975","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}
Pub Date : 2026-01-01DOI: 10.1016/j.micron.2025.103986
Ruth Birch , Shuheng Li , Sharang Sharang , Warren J. Poole , Ben Britton
Characterization of the structure and properties of materials in three dimensions, including grains and the residual pattern of deformation, provides necessary information required to guide materials design as well as support materials modelling efforts. In this work, we present an overview of site-specific large volume ‘chunk’ lift out and 3D serial sectioning of substantive volumes (e.g. 200 ×200 x 400 μm3), where sectioning is optimized for 3D electron backscatter diffraction (EBSD) based crystallographic analysis, using a plasma (Xe) focussed ion beam scanning electron microscope (plasma FIB-SEM) equipped to perform EBSD using a ‘static’ configuration (i.e. slicing and EBSD-mapping are performed without moving the sample). This workflow is demonstrated through the 3D plasma FIB-SEM based EBSD analysis of an indent made within a polycrystal of pure magnesium. The lift out approach is suitable for a wide range of materials, and we offer a step-by-step guide within the present work to provide opportunity for others to more easily enter this field and collect valuable data.
三维表征材料的结构和性能，包括颗粒和变形的残余模式，为指导材料设计和支持材料建模工作提供了必要的信息。在这项工作中，我们概述了特定位置的大体积“块”提升和实质性体积的3D连续切片（例如200 ×200 x 400 μm3），其中切片针对基于3D电子后向散射衍射（EBSD）的晶体学分析进行了优化，使用等离子体（Xe）聚焦离子束扫描电子显微镜（等离子体FIB-SEM），该显微镜配备了使用“静态”配置执行EBSD（即切片和EBSD映射在不移动样品的情况下执行）。该流程通过基于3D等离子体FIB-SEM的EBSD分析纯镁多晶内的压痕来演示。提升方法适用于广泛的材料，我们在目前的工作中提供一步一步的指导，为其他人更容易进入这一领域并收集有价值的数据提供机会。
{"title":"Large volume ‘chunk’ lift out for 3D tomographic analysis using analytical plasma focussed ion beam – scanning electron microscopy","authors":"Ruth Birch , Shuheng Li , Sharang Sharang , Warren J. Poole , Ben Britton","doi":"10.1016/j.micron.2025.103986","DOIUrl":"10.1016/j.micron.2025.103986","url":null,"abstract":"<div><div>Characterization of the structure and properties of materials in three dimensions, including grains and the residual pattern of deformation, provides necessary information required to guide materials design as well as support materials modelling efforts. In this work, we present an overview of site-specific large volume ‘chunk’ lift out and 3D serial sectioning of substantive volumes (e.g. 200 ×200 x 400 μm<sup>3</sup>), where sectioning is optimized for 3D electron backscatter diffraction (EBSD) based crystallographic analysis, using a plasma (Xe) focussed ion beam scanning electron microscope (plasma FIB-SEM) equipped to perform EBSD using a ‘static’ configuration (i.e. slicing and EBSD-mapping are performed without moving the sample). This workflow is demonstrated through the 3D plasma FIB-SEM based EBSD analysis of an indent made within a polycrystal of pure magnesium. The lift out approach is suitable for a wide range of materials, and we offer a step-by-step guide within the present work to provide opportunity for others to more easily enter this field and collect valuable data.</div></div>","PeriodicalId":18501,"journal":{"name":"Micron","volume":"203 ","pages":"Article 103986"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145917775","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}
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