Ultramicroscopy最新文献

{"title":"Ultrastructure of antennal sensilla of Anastatus orientalis (Hymenoptera: Eupelmidae), an egg parasitoid of the invasive spotted lanternfly, Lycorma delicatula (Hemiptera: Fulgoridae)","authors":"Le Liu,&nbsp;Ke Wei,&nbsp;Ke-Xin Bao,&nbsp;Ji-Yu Xie,&nbsp;Xiao-Yi Wang","doi":"10.1016/j.ultramic.2025.114179","DOIUrl":"10.1016/j.ultramic.2025.114179","url":null,"abstract":"<div><div><em>Anastatus orientalis</em> (Hymenoptera: Eupelmidae) is an egg parasitoid of the internationally quarantined pest <em>Lycorma delicatula</em>, and can be used as a potential biological control agent in practice. Antennae are the important olfactory organs that play a key role in host-parasitoid chemical communication. Therefore, recognition of morphological features is crucial for investigating the olfactory behavior mechanism of parasitic wasps. Here, we observed the ultrastructure of sensilla on the antennae in male and female wasps of <em>A. orientalis</em> using scanning electron microscope. Our results revealed that the antennae of <em>A. orientalis</em> are geniculate, with 13 segments in female wasps and 10 segments in males. The average length of female antennae (1761.17 ± 60.77) μm was shorter than that of males (1883.06 ± 95.68) μm. Ten morphological types of antennal sensilla were found on <em>A. orientalis</em> antennae, including sensilla trichodea (ST), sensilla chaetica (SC), sensilla basiconica (SB), i-type sensilla (IS), corneous sensilla (CS), sensilla campaniformia (Ca), sensilla placodea (Pl), lance sensilla (LS), sensilla coeloconica (Co), and böhm bristles (BBs). Among these, ST had two subtypes (ST I and ST II). SC and Pl were the most abundant sensilla on the antennae of <em>A. orientalis</em>, with wide distribution and large number. Sexual dimorphism was observed in the length, width, abundance, and distribution of sensilla on the antennae. IS were unique to female wasps, suggesting their important role in the recognition and acceptance of host eggs.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"276 ","pages":"Article 114179"},"PeriodicalIF":2.1,"publicationDate":"2025-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144196496","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":"Multimode objective lens for momentum microscopy and XPEEM: Theory","authors":"Olena Tkach,&nbsp;Gerd Schönhense","doi":"10.1016/j.ultramic.2025.114167","DOIUrl":"10.1016/j.ultramic.2025.114167","url":null,"abstract":"<div><div>The strong electric field between the sample and the extractor is at the heart of cathode lenses and a crucial factor for high resolution. However, fields in the range of 3-10 kV/mm can be a source of complications. Local field enhancement at sharp edges or microscopic protrusions of cleaved samples can lead to field emission or flashovers. In addition, slow background electrons drawn into the microscope column contribute to space charge effects. A novel objective configuration, optimized by ray-tracing simulations at energies from a few eV to 6 keV, significantly reduces the field at the sample. One or more annular electrodes concentric to the extractor can shape the electric field in front of the sample. The formation of a ‘gaplens’ reduces the field to values below the 1 kV/mm range. Tuning the field to zero is advantageous for 3D structured samples. Retarding fields repel slow electrons, suppressing space charge effects. The properties of the different lens modes are investigated using ray tracing and determination of aberration coefficients. Despite its much lower electric field, the gaplens mode exhibits smaller aberrations and enables larger fields of view for both momentum and real space imaging. At electric fields as low as 1200 and 880 V/mm, the accessible solid angle interval in the gaplens mode is three times larger than in the extractor mode (with a start energy of 100 eV and a <em>k</em>-resolution of 10^-2 Å^-1). Due to the elimination of space charge effects in the retarding field mode, XPEEM resolutions in the range of 25 nm are predicted. The ray tracing results are confirmed by the spherical and chromatic aberration coefficients of the real-space and <em>k</em>-space images.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"276 ","pages":"Article 114167"},"PeriodicalIF":2.1,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144205668","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":"Momentum microscopy with combined hemispherical and time-of-flight electron analyzers at the soft X-ray beamline I09 of the diamond light source","authors":"Matthias Schmitt ,&nbsp;Deepnarayan Biswas ,&nbsp;Olena Tkach ,&nbsp;Olena Fedchenko ,&nbsp;Jieyi Liu ,&nbsp;Hans-Joachim Elmers ,&nbsp;Michael Sing ,&nbsp;Ralph Claessen ,&nbsp;Tien-Lin Lee ,&nbsp;Gerd Schönhense","doi":"10.1016/j.ultramic.2025.114169","DOIUrl":"10.1016/j.ultramic.2025.114169","url":null,"abstract":"<div><div>The three-dimensional recording scheme of time-of-flight momentum microscopes (ToF-MMs) is advantageous for fast mapping of the photoelectron distribution in (<em>E</em>,<strong><em>k</em></strong>) parameter space over the entire Brillouin zone. However, the 2 ns pulse period of most synchrotrons is too short for pure ToF photoelectron spectroscopy. The use of a hemispherical analyzer (HSA) as a pre-filter allows ToF-MM at such high pulse rates. The first HSA &amp; ToF hybrid MM is operated at the soft X-ray branch of beamline I09 at the Diamond Light Source, UK. The photon energy ranges from 105 eV to 2 keV, with circular polarization available for hν ≥ 145 eV. The HSA reduces the transmitted energy band to typically 0.5 eV, which is then further analyzed by ToF recording. In initial experiments, the overall efficiency gain when switching from the standard 2D (<em>k</em>_x,<em>k</em>_y) mode to the 3D (<em>k</em>_x,<em>k</em>_y,<em>E</em>_kin) hybrid mode was about 24. This value is determined by the number of resolved kinetic energies (here 12) and the transmission gain of the electron optics due to the high pass energy of the HSA in hybrid mode (<em>E</em>_pass up to 500 eV). The transmission gain depends on the size of the photon footprint on the sample. Under <em>k</em>-imaging conditions, the energy and momentum resolution are 10.2 meV (FWHM) (4.2 meV with 200 μm slits and <em>E</em>_pass = 8 eV) and 0.010 Å^-1. The energy filtered X-PEEM mode showed a spatial resolution of 250 nm. As examples, we show 2D band mapping of bilayer graphene, 3D mapping of the Fermi surface of Cu, circular dichroic ARPES for intercalated indenene layers, and the <em>sp</em> valence band of Au. Full-field photoelectron diffraction patterns of Ge show rich structure in <em>k</em>-field diameters of up to 6 Å^-1.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"276 ","pages":"Article 114169"},"PeriodicalIF":2.1,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144205702","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":"An unbiased ADMM-TGV algorithm for the deconvolution of STEM-EELS maps","authors":"Christian Zietlow,&nbsp;Jörg K.N. Lindner","doi":"10.1016/j.ultramic.2025.114159","DOIUrl":"10.1016/j.ultramic.2025.114159","url":null,"abstract":"<div><div>Electron-energy-loss-spectroscopy (EELS) spectra in the scanning transmission electron microscope (STEM) are affected by various types of noise. Additionally, they are convolved with the detector point spread function and the energy distribution of the electron source. Often, iterative deconvolution is employed to sharpen peaks and improve the data. However, since the Richardson–Lucy algorithm (RLA) has become the standard deconvolution algorithm in EELS, little progress has been made in terms of technique. In this paper, the authors aim to provide an update to STEM-EELS deconvolution and demonstrate how to significantly improve results compared to those achievable with the RLA. The major limitation of the RLA is that it does not guarantee convergence. Furthermore, the RLA is restricted to pure Poisson noise and lacks adaptability due to limitations in its general structure, particularly when compared to more modern algorithms. A new and versatile approach is the Alternating Direction Method of Multipliers (ADMM), which is based on Lagrangian methods and enables to overcome these restrictions. The generality of ADMM allows us to develop a deconvolution algorithm tailored to EELS maps and incorporate a recent noise model. We extend the standard Bayesian maximum likelihood of the RLA to a maximum a-posteriori approach in ADMM, which enables us to leverage the principles of total general variation (TGV) to enforce convergence. Furthermore, we define the algorithm such that it operates unbiased of the user. To demonstrate the superiority of the ADMM, it is tested against the RLA using simulated data. Eventually, our algorithm is successfully applied to experimental data as well.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"275 ","pages":"Article 114159"},"PeriodicalIF":2.1,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144088772","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":"Laser-driven cold field emission source for ultrafast transmission electron microscopy","authors":"Alexander Schröder ,&nbsp;Andreas Wendeln ,&nbsp;Jonathan T. Weber ,&nbsp;Masaki Mukai ,&nbsp;Yuji Kohno ,&nbsp;Sascha Schäfer","doi":"10.1016/j.ultramic.2025.114158","DOIUrl":"10.1016/j.ultramic.2025.114158","url":null,"abstract":"<div><div>Ultrafast transmission electron microscopy (UTEM) has emerged as a versatile technique for the time-resolved imaging of nanoscale dynamics on timescales down to few-hundred attoseconds but the temporal and spatial resolutions are still limited by the coherence properties of pulsed electron sources. Here, we report the development of a novel laser-driven linear cold field electron emitter integrated in a state-of-the-art UTEM system. Tuning the emitter’s workfunction via an applied extraction field and illuminating the sharp tungsten emitter tip with UV light pulses generates ultrashort femtosecond electron pulses of 220 fs pulse duration at 200 keV electron energy, with energy widths as low as 360 meV. The photoelectron emitter demonstrates exceptional spatial coherence, achieving focal spot sizes down to 2 Å and a peak normalized brightness exceeding 6.7 <span><math><mrow><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>13</mn></mrow></msup></mrow></math></span> A/m<span><math><msup><mrow></mrow><mrow><mn>2</mn></mrow></msup></math></span>sr. With an order-of-magnitude improvement compared to previously employed laser-driven Schottky field emitters, the present development opens up the field of ultrafast atomic-scale electron probing.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"275 ","pages":"Article 114158"},"PeriodicalIF":2.1,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144155180","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":"Data-driven control in atomic force microscopy using a genetic algorithm","authors":"Navid Asmari ,&nbsp;Lukas Neuner ,&nbsp;Richard Weiss ,&nbsp;Amin Mazloumian ,&nbsp;Matthias Rosenthal ,&nbsp;Alireza Karimi ,&nbsp;Georg Ernest Fantner","doi":"10.1016/j.ultramic.2025.114156","DOIUrl":"10.1016/j.ultramic.2025.114156","url":null,"abstract":"<div><div>Increasing the scanning speed in Atomic Force Microscopy (AFM) relies on improving the tracking performance in the vertical direction of motion. The lightly damped resonances of piezo-actuators utilized in AFM nano-positioning stages hinder the maximum achievable bandwidth in tracking sample topographies. A high-order linear controller is proposed as solution. This controller is placed in series with the conventional proportional-integral (PI) controller in AFM to cancel the resonances and push the bandwidth limits to higher values. An optimization problem is formed based on the frequency response of the actuator and the desired performance characteristics for the system. The controller is shaped by solving this problem with a genetic algorithm. Implementing the proposed controller on several AFM scanners shows its effectiveness in improving the tracking bandwidth and hence, increasing the achievable scan speed.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"275 ","pages":"Article 114156"},"PeriodicalIF":2.1,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144088773","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":"Quantitative magnetic mapping in TEM through accurate 2D thickness determination","authors":"Joseph Vimal Vas ,&nbsp;Hasan Ali ,&nbsp;Wen Shi ,&nbsp;Thibaud Denneulin ,&nbsp;Ayush K Gupta ,&nbsp;Rohit Medwal ,&nbsp;Rafal E. Dunin-Borkowski","doi":"10.1016/j.ultramic.2025.114140","DOIUrl":"10.1016/j.ultramic.2025.114140","url":null,"abstract":"<div><div>Off-axis Electron Holography and Electron Magnetic Circular Dichroism are powerful Transmission Electron Microscopy (TEM) techniques capable of mapping magnetic information with near-atomic spatial resolution. However, the magnetic signals obtained is semi-quantitative due to factors such as thickness variations and local crystallographic changes. Precise determination of spatial thickness variations can make these techniques more quantitative. Electron Energy Loss Spectroscopy (EELS) provides a method to measure thickness variations within a region of interest. The absolute thickness depends on reliable estimates of the inelastic mean free path (<span><math><mi>λ</mi></math></span>), which is often unknown for many materials. Alternative techniques, such as Scanning Electron Microscopy (SEM) and Convergent Beam Electron Diffraction (CBED), either lack spatial resolution in thickness mapping or are accurate only within a limited thickness range. Here, we present a straightforward approach to precisely determine the inelastic mean free path (<span><math><mi>λ</mi></math></span>), enabling accurate thickness measurements from EELS maps. We compare these thickness measurements with CBED- and SEM-based methods, identifying discrepancies, particularly in thinner samples (<span><math><mrow><mo>&lt;</mo><mn>100</mn><mspace></mspace><mi>nm</mi></mrow></math></span>). Finally, we demonstrate how this calibrated thickness measurement can provide quantitative magnetic maps using TEM-based magnetic measurements.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"275 ","pages":"Article 114140"},"PeriodicalIF":2.1,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144069971","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":"An improved soft-thresholding exit wave reconstruction for imaging beam-sensitive materials","authors":"Hongsheng Shi ,&nbsp;Yuan Lu ,&nbsp;Zeyu Wang ,&nbsp;Shuchen Zhang ,&nbsp;Yi Yu","doi":"10.1016/j.ultramic.2025.114154","DOIUrl":"10.1016/j.ultramic.2025.114154","url":null,"abstract":"<div><div>High-resolution transmission electron microscopy (HRTEM) is a widely-used technique for atomic-scale characterization. However, the conventional dose of HRTEM can destroy beam-sensitive materials such as organic-inorganic halide perovskites. CH₃NH₃PbI₃ (MAPbI₃), a typical perovskite, will be easily damaged after irradiated with the dose of ∼10² e-/Ų. Low-dose imaging techniques can protect the specimen but it is difficult to achieve an image which is both directly interpreted and atomically clear. Exit wave reconstruction (EWR), as one of phase retrieval methods, can recover an interpretable phase image at the atomic scale but its signal-to-noise ratio (SNR) is limited by low electron doses. Here, we improve the iterative wave function reconstruction (IWFR) method and present a soft-thresholding L₁-IWFR. Results from both simulated and experimental focal-series dataset at the extremely low dose show that L₁-IWFR improves the SNR effectively and has better performance on low-dose datasets than IWFR. Combined with low-dose imaging techniques and various alignment strategies, an atomically clear image of CH₃NH₃PbI₃ (MAPbI₃) is successfully achieved at the total dose of ∼45 e^-/Ų.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"274 ","pages":"Article 114154"},"PeriodicalIF":2.1,"publicationDate":"2025-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143928576","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":"Compact design, construction, and evaluation of an in situ ±90° rotatable magnetic force microscope in a 12 T superconducting magnet","authors":"Min Zhang ,&nbsp;Shuai Dong ,&nbsp;Zihao Li ,&nbsp;Kesen Zhao ,&nbsp;Aile Wang ,&nbsp;Wenjie Meng ,&nbsp;Qiyuan Feng ,&nbsp;Jing Zhang ,&nbsp;Jihao Wang ,&nbsp;Yalin Lu ,&nbsp;Yubin Hou ,&nbsp;Qingyou Lu","doi":"10.1016/j.ultramic.2025.114155","DOIUrl":"10.1016/j.ultramic.2025.114155","url":null,"abstract":"<div><div>Cryogenic magnetic force microscopy (MFM) is a powerful technique capable of resolving exotic magnetic textures with nanoscale resolution in real-space. We introduce a cryogenic rotatable MFM (CRMFM) that enables the visualization of in situ evolution of magnetic domains by rotating magnetic samples between −90° and +90° within a 12 T superconducting magnet. By continuously rotating the sample under an external magnetic field, the direction of the magnetic field can be varied from out-of-plane to in-plane, enabling microscopic analysis experiments that require vector magnetic fields within the CRMFM system. By using CRMFM measurements, we successfully transformed long magnetic stripe domains into isolated magnetic bubble domains and proposed a novel strategy for visualizing stripe-bubble transitions in magnetic domains. Additionally, we demonstrated that the CRMFM system can generate high-quality MFM images under in-plane magnetic fields up to 12 T. Our research provides a framework for visualizing the interaction between ferromagnetism and magnetic field direction, facilitating the study of magnetic crystal anisotropy.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"274 ","pages":"Article 114155"},"PeriodicalIF":2.1,"publicationDate":"2025-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143931517","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":"High-precision atomic imaging using an innovative vibration-isolated scanning tunneling microscope","authors":"Behnam Esmaeilzadeh ,&nbsp;Muhammad Touqeer ,&nbsp;Syed Asad Maqbool ,&nbsp;Jihao Wang ,&nbsp;Wenjie Meng ,&nbsp;Yubin Hou ,&nbsp;Yalin Lu ,&nbsp;Qingyou Lu","doi":"10.1016/j.ultramic.2025.114157","DOIUrl":"10.1016/j.ultramic.2025.114157","url":null,"abstract":"<div><div>The stability of the scanning unit in a scanning tunneling microscope (STM) is essential for achieving high-resolution imaging. In this study, we present a non-metallic STM with a mechanically isolated scanning unit, ensuring long-term drift stability, low backlash, and high repeatability. By decoupling the piezoelectric scanning tube (PST) from the piezoelectric motor tube (PMT), the design effectively minimizes motor-induced instabilities and vibrations, significantly improving STM performance. The use of non-metallic materials for key components prevents eddy current interference and ensures long-term reliability. A sapphire-based frame provides high stiffness and compactness, with an eigenfrequency of 16.2 kHz in bending mode, reducing vibration noise during atomic imaging. The system exhibits excellent stability, maintaining low drift rates in both the X-Y plane and Z direction, ensuring precise tip-sample alignment. The performance of the home-built STM was validated through high-resolution atomic imaging of graphite and TaS₂ surfaces. The simple, compact, and high-precision stepping mechanism, along with its ability to operate at low voltage, reduces experimental complexity. These features facilitate advanced material studies in constrained environments, such as high magnetic fields and low temperatures.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"274 ","pages":"Article 114157"},"PeriodicalIF":2.1,"publicationDate":"2025-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143924223","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}