Ultramicroscopy最新文献_第10页

Ultra-low-noise transimpedance amplifier with a single HEMT in pre-amplifier for measuring shot noise in cryogenic STM 超低噪声互阻抗放大器，前置放大器采用单 HEMT，用于测量低温 STM 中的射出噪声

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2024-09-19 DOI: 10.1016/j.ultramic.2024.114051

Ying-Xin Liang

{"title":"Ultra-low-noise transimpedance amplifier with a single HEMT in pre-amplifier for measuring shot noise in cryogenic STM","authors":"Ying-Xin Liang","doi":"10.1016/j.ultramic.2024.114051","DOIUrl":"10.1016/j.ultramic.2024.114051","url":null,"abstract":"<div><div>In this work, a design of transimpedance amplifier (TIA) for cryogenic scanning tunneling microscope (CryoSTM) is proposed. TIA with the tip-sample component in CryoSTM is called as CryoSTM-TIA. With transimpedance gain of 1 G<span><math><mi>Ω</mi></math></span>, the bandwidth of the CryoSTM-TIA is larger than 200 kHz. The distinctive feature of the proposed CryoSTM-TIA is that its pre-amplifier is made of a single cryogenic high electron mobility transistor (HEMT), so the apparatus equivalent input noise current power spectral density at 100 kHz is lower than 6 (fA)<span><math><msup><mrow></mrow><mrow><mn>2</mn></mrow></msup></math></span>/Hz. In addition, “bias-cooling method” can be used to in-situ control the density of the frozen DX<span><math><msup><mrow></mrow><mrow><mo>−</mo></mrow></msup></math></span> centers in the HEMT doping area, changing its structure to reduce the device noises. With this apparatus, fast scanning tunneling spectra measurements with high-energy-resolution are capable to be performed. And, it is capable to measure scanning tunneling shot noise spectra (STSNS) at the atomic scale for various quantum systems, even if the shot noise is very low. It provides a powerful tool to investigate novel quantum states by measuring STSNS, such as detecting the existence of Majorana bound states in the topological quantum systems.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"267 ","pages":"Article 114051"},"PeriodicalIF":2.1,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142328350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

On the temporal transfer function in STEM imaging from finite detector response time 从有限探测器响应时间看 STEM 成像中的时间传递函数

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2024-09-19 DOI: 10.1016/j.ultramic.2024.114056

Jonathan J.P. Peters , Tiarnan Mullarkey , Julie Marie Bekkevold , Matthew Geever , Ryo Ishikawa , Naoya Shibata , Lewys Jones

引用次数: 0

Characterization of strongly coupled quartz tuning fork sensors for precision force measurement in atomic force microscopy 用于原子力显微镜精确测力的强耦合石英音叉传感器的特性分析

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2024-09-18 DOI: 10.1016/j.ultramic.2024.114052

Cedric Shaskey , Amun Jarzembski , Andrew Jue , Keunhan Park

{"title":"Characterization of strongly coupled quartz tuning fork sensors for precision force measurement in atomic force microscopy","authors":"Cedric Shaskey , Amun Jarzembski , Andrew Jue , Keunhan Park","doi":"10.1016/j.ultramic.2024.114052","DOIUrl":"10.1016/j.ultramic.2024.114052","url":null,"abstract":"<div><p>Miniaturized quartz tuning forks (QTFs) have been adopted as force sensors for non-contact atomic force microscopy (AFM). However, the coupled oscillation behaviors of the QTF prongs are not well understood, preventing quantitative measurement of the nanoscale tip-sample interaction forces. This article presents a lumped model that accurately delineates the coupled mechanical oscillations of QTF prongs, establishing rigorous relationships between experimental observables and tip-sample interaction forces. The first-order resonance spectra of a commercial QTF were fully characterized by correlating its piezoelectric response with the actual mechanical oscillation measured with a Fabry-Pérot interferometer. In order to uniquely determine the modeling parameters (i.e., the effective masses, spring constants, and damping constants), the experimental results were compared with the lumped model predictions while masses were added to one prong. The results reveal that the QTF’s center of mass is highly damped, preventing the observation of a symmetric resonance mode. In addition, the mass loading experiment demonstrates that the mechanical oscillations of the QTF prongs are strongly coupled, accounting for 59% (84%) of the effective stiffness at the in-plane (out-of-plane), antisymmetric resonance mode. We believe that the obtained QTF characterization results will pave the way for quantitative measurements of non-contact interaction forces in QTF-based AFM platforms, significantly improving the precision and reliability of nanoscale force measurements.</p></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"267 ","pages":"Article 114052"},"PeriodicalIF":2.1,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142271112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effective removal of global tilt from atomically-resolved topography images of vicinal surfaces with narrow terraces 从具有窄梯田的邻接表面的原子分辨地形图像中有效去除全局倾斜

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2024-09-18 DOI: 10.1016/j.ultramic.2024.114053

A.Yu. Aladyshkin , A.N. Chaika , V.N. Semenov , A.M. Ionov , S.I. Bozhko

引用次数: 0

Automated detection and mapping of crystal tilt using thermal diffuse scattering in transmission electron microscopy 在透射电子显微镜中利用热漫散射自动检测和绘制晶体倾斜图

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2024-09-18 DOI: 10.1016/j.ultramic.2024.114050

Mauricio Cattaneo , Knut Müller-Caspary , Juri Barthel , Katherine E. MacArthur , Nicolas Gauquelin , Marta Lipinska-Chwalek , Johan Verbeeck , Leslie J. Allen , Rafal E. Dunin-Borkowski

{"title":"Automated detection and mapping of crystal tilt using thermal diffuse scattering in transmission electron microscopy","authors":"Mauricio Cattaneo , Knut Müller-Caspary , Juri Barthel , Katherine E. MacArthur , Nicolas Gauquelin , Marta Lipinska-Chwalek , Johan Verbeeck , Leslie J. Allen , Rafal E. Dunin-Borkowski","doi":"10.1016/j.ultramic.2024.114050","DOIUrl":"10.1016/j.ultramic.2024.114050","url":null,"abstract":"<div><p>Quantitative interpretation of transmission electron microscopy (TEM) data of crystalline specimens often requires the accurate knowledge of the local crystal orientation. A method is presented which exploits momentum-resolved scanning TEM (STEM) data to determine the local mistilt from a major zone axis. It is based on a geometric analysis of Kikuchi bands within a single diffraction pattern, yielding the center of the Laue circle. Whereas the approach is not limited to convergent illumination, it is here developed using unit-cell averaged diffraction patterns corresponding to high-resolution STEM settings. In simulation studies, an accuracy of approximately 0.1 mrad is found. The method is implemented in automated software and applied to crystallographic tilt and in-plane rotation mapping in two experimental cases. In particular, orientation maps of high-Mn steel and an epitaxially grown La<span><math><msub><mrow></mrow><mrow><mtext>0.7</mtext></mrow></msub></math></span>Sr<span><math><msub><mrow></mrow><mrow><mtext>0.3</mtext></mrow></msub></math></span>MnO<span><math><msub><mrow></mrow><mrow><mtext>3</mtext></mrow></msub></math></span>-SrTiO<span><math><msub><mrow></mrow><mrow><mtext>3</mtext></mrow></msub></math></span> interface are presented. The results confirm the estimates of the simulation study and indicate that tilt mapping can be performed consistently over a wide field of view with diameters well above 100 nm at unit cell real space sampling.</p></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"267 ","pages":"Article 114050"},"PeriodicalIF":2.1,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142271111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A new method for estimating nanoparticle deposition coverage from a set of weak-contrast SEM images 从一组弱对比 SEM 图像中估算纳米粒子沉积覆盖率的新方法

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2024-09-14 DOI: 10.1016/j.ultramic.2024.114048

Bchara Sidnawi , Liang Zhao , Bo Li , Qianhong Wu

{"title":"A new method for estimating nanoparticle deposition coverage from a set of weak-contrast SEM images","authors":"Bchara Sidnawi , Liang Zhao , Bo Li , Qianhong Wu","doi":"10.1016/j.ultramic.2024.114048","DOIUrl":"10.1016/j.ultramic.2024.114048","url":null,"abstract":"<div><p>Imaging nanomaterials in hybrid systems is critical to understanding the structure and functionality of these systems. However, current technologies such as scanning electron microscopy (SEM) may obtain high resolution/contrast images at the cost of damaging or contaminating the sample. For example, to prevent the charging of organic substrate/matrix, a very thin layer of metal is coated on the surface, which will permanently contaminate the sample and eliminate the possibility of reusing it for following processes. Conversely, examining the sample without any modifications, in pursuit of high-fidelity digital images of its unperturbed state, can come at the cost of low-quality images that are challenging to process. Here, a solution is proposed for the case where no brightness threshold is available to reliably judge whether a region is covered with nanomaterials. The method examines local brightness variability to detect nanomaterial deposits. Very good agreement with manually obtained values of the coverage is observed, and a strong case is made for the method's automatability. Although the developed methodology is showcased in the context of SEM images of Polydimethylsiloxane (PDMS) substrates on which silicone dioxide (SiO<sub>2</sub>) nanoparticles are assembled, the underlying concepts may be extended to situations where straightforward brightness thresholding is not viable.</p></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"267 ","pages":"Article 114048"},"PeriodicalIF":2.1,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142271110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Theoretical study on the effect of temperature gradient on contact-free scanning for scanning ion conductance microscopy 关于温度梯度对扫描离子电导显微镜非接触扫描影响的理论研究

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2024-09-14 DOI: 10.1016/j.ultramic.2024.114054

Zhiwu Wang , Jian Zhuang , Lidong Zhou , Hongjuan Li , Shaohui Ning , Xiaobo Liao

{"title":"Theoretical study on the effect of temperature gradient on contact-free scanning for scanning ion conductance microscopy","authors":"Zhiwu Wang , Jian Zhuang , Lidong Zhou , Hongjuan Li , Shaohui Ning , Xiaobo Liao","doi":"10.1016/j.ultramic.2024.114054","DOIUrl":"10.1016/j.ultramic.2024.114054","url":null,"abstract":"<div><p>Scanning ion-conductance microscopy (SICM) is a non-contact, high-resolution, and <em>in-situ</em> scanning probe microscope technique, it can be operated in probing the physical and chemical properties of biological samples such as living cells. Recently, using SICM to study the effects of microenvironment changes such as temperature changes on response of the biological samples has attracted significant attention. However, in this temperature gradient condition, one of the crucial but still unclear issues is the scanning feedback types and safe threshold. In this paper, a theoretical study of effect of the temperature gradient in electrolyte or sample surface on the SICM safe ion-current threshold is conducted using three-dimensional Poisson-Nernst-Planck, Navier-Stokes and energy equations. Two temperature gradient types, sample surface and two types of pipettes with different ratio of inner and outer radii are included, respectively. The results demonstrate that the local temperature of the electrolyte and then sample surface significantly affect the ion flow, shape of the approach curves and thus safe threshold in SICM pipette probe for contact-free scanning. There is a current-increased and decreased phases for approaching the surface with higher temperature and two current-decreased phases for surface with lower temperature. Based on this shape feature of approach curves, the change rate of current is analysis to illustrate the possibility for contact-free scanning of slope object. The results indicate that with the decrease of the normalized tip-surface distance, the coupling effect of large slope angle and local high temperature makes the increase in change rate of ion current not significant and then it challenging to realize contact-free scanning especially for higher surface temperature.</p></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"267 ","pages":"Article 114054"},"PeriodicalIF":2.1,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142238089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Maximizing the notional area in single tip field emitters 最大化单尖端场发射器的名义面积

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2024-09-13 DOI: 10.1016/j.ultramic.2024.114049

Sergey V. Filippov , Fernando F. Dall’Agnol , Eugeni O. Popov , Anatoly G. Kolosko , Thiago A. de Assis

{"title":"Maximizing the notional area in single tip field emitters","authors":"Sergey V. Filippov , Fernando F. Dall’Agnol , Eugeni O. Popov , Anatoly G. Kolosko , Thiago A. de Assis","doi":"10.1016/j.ultramic.2024.114049","DOIUrl":"10.1016/j.ultramic.2024.114049","url":null,"abstract":"<div><p>One of the critical aspects in advancing high-brightness field emitter devices is determining the conditions under which single-tip emitters should be constructed to optimize their emission area. Recent experiments have explored varying the axis ratio <span><math><mi>ξ</mi></math></span> of the cap of a single-tip emitter, ranging from an oblate semi-spheroid to a prolate shape, mounted on a nearly cylindrical conducting body. In this work, we present a strategy, based on high-accuracy computer simulations using the finite element technique, to maximize the emission area of those single-tip emitters. Importantly, our findings indicate that the notional emission area achieves its maximum when the emitter’s cap is adjusted to an oblate semi-spheroid with a characteristic axis ratio <span><math><mrow><msub><mrow><mi>ξ</mi></mrow><mrow><mi>C</mi></mrow></msub><mo>≈</mo><mn>0</mn><mo>.</mo><mn>85</mn></mrow></math></span>. We do a comparison of notional emission area as a function of <span><math><mi>ξ</mi></math></span> for an ellipsoidal emitter on a post and compare these results from other emitter configurations, which are feasible to fabricate.</p></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"267 ","pages":"Article 114049"},"PeriodicalIF":2.1,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142238088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Atomic resolution scanning transmission electron microscopy at liquid helium temperatures for quantum materials 液氦温度下用于量子材料的原子分辨率扫描透射电子显微镜

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2024-09-07 DOI: 10.1016/j.ultramic.2024.114039

Junsik Mun , Daniel Potemkin , Houk Jang , Suji Park , Stephen Mick , Cedomir Petrovic , Sang-Wook Cheong , Myung-Geun Han , Yimei Zhu

{"title":"Atomic resolution scanning transmission electron microscopy at liquid helium temperatures for quantum materials","authors":"Junsik Mun , Daniel Potemkin , Houk Jang , Suji Park , Stephen Mick , Cedomir Petrovic , Sang-Wook Cheong , Myung-Geun Han , Yimei Zhu","doi":"10.1016/j.ultramic.2024.114039","DOIUrl":"10.1016/j.ultramic.2024.114039","url":null,"abstract":"<div><p>Fundamental quantum phenomena in condensed matter, ranging from correlated electron systems to quantum information processors, manifest their emergent characteristics and behaviors predominantly at low temperatures. This necessitates the use of liquid helium (LHe) cooling for experimental observation. Atomic resolution scanning transmission electron microscopy combined with LHe cooling (cryo-STEM) provides a powerful characterization technique to probe local atomic structural modulations and their coupling with charge, spin and orbital degrees-of-freedom in quantum materials. However, achieving atomic resolution in cryo-STEM is exceptionally challenging, primarily due to sample drifts arising from temperature changes and noises associated with LHe bubbling, turbulent gas flow, etc. In this work, we demonstrate atomic resolution cryo-STEM imaging at LHe temperatures using a commercial side-entry LHe cooling holder. Firstly, we examine STEM imaging performance as a function of He gas flow rate, identifying two primary noise sources: He-gas pulsing and He-gas bubbling. Secondly, we propose two strategies to achieve low noise conditions for atomic resolution STEM imaging: either by temporarily suppressing He gas flow rate using the needle valve or by acquiring images during the natural warming process. Lastly, we show the applications of image acquisition methods and image processing techniques in investigating structural phase transitions in Cr<sub>2</sub>Ge<sub>2</sub>Te<sub>6</sub>, CuIr<sub>2</sub>S<sub>4</sub>, and CrCl<sub>3</sub>. Our findings represent an advance in the field of atomic resolution electron microscopy imaging for quantum materials and devices at LHe temperatures, which can be applied to other commercial side-entry LHe cooling TEM holders.</p></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"267 ","pages":"Article 114039"},"PeriodicalIF":2.1,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142230370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Development of a liquid-helium free cryogenic sample holder with mK temperature control for autonomous electron microscopy 开发用于自主电子显微镜的 mK 温度控制无液氦低温样品支架。

IF 2.1 3区工程技术

Ultramicroscopy Pub Date : 2024-09-07 DOI: 10.1016/j.ultramic.2024.114037

X. He , R. Kostin , E. Knight , M.G. Han , J. Mun , I. Bozovic , C. Jing , Y. Zhu

{"title":"Development of a liquid-helium free cryogenic sample holder with mK temperature control for autonomous electron microscopy","authors":"X. He , R. Kostin , E. Knight , M.G. Han , J. Mun , I. Bozovic , C. Jing , Y. Zhu","doi":"10.1016/j.ultramic.2024.114037","DOIUrl":"10.1016/j.ultramic.2024.114037","url":null,"abstract":"<div><div>The automated and autonomous cryogenic transmission electron microscopy (Cryo-EM) demands a sample holder capable of maintaining temperatures below 10 K with precise control, long holding times, and minimal helium use. Rising to this challenge, we initiated an ambitious project to develop a novel closed-cycle cryocooler-based cryogenic sample holder that operates without the use of liquid helium and the consumption of gaseous helium. This article presents the design, construction, and experimental testing of the initial prototype, which achieves an ultimate temperature of 5.6 K with exceptional stability close to 1mK, while providing a wide temperature control range from 295 K to 5.6 K, marking a clear advancement in cryo-EM holder development. While the prototype was not designed for atomic resolution imaging and thus lacks a sturdy support system to mitigate mechanical vibrations from the cryocooler's pulsed tube, this innovative approach successfully demonstrates proof of concept. It offers unprecedented capabilities for state-of-the-art cryogenic microscopy and microanalysis in materials and biological sciences.</div></div>","PeriodicalId":23439,"journal":{"name":"Ultramicroscopy","volume":"267 ","pages":"Article 114037"},"PeriodicalIF":2.1,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142393722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0