Pub Date : 2025-01-19DOI: 10.1016/j.vacuum.2025.114051
Yanming He , Suqing Yao , Jialong Nie , Jiabing Liang , Huaxin Li , Lei Shi , Yuan Sun , Shengxuan Yang , Weijiang Guo , Chuanyang Lu , Jianguo Yang , Yafei Li
The Mo-14Re/Inconel 625 alloy joint brazed using traditional BNi-2 or Cu interlayers generally exhibited unsatisfactory bonding strength and cracks due to a large mismatch of coefficient of thermal expansion (CTE) between the base materials. In this study, Mo-14Re and Inconel 625 were brazed using two routes: 1) One-step brazing with Au-Ni paste achieved a shear strength up to 547.9 MPa, due to the predominance of high-strength and ductile Au(s,s) in the brazed joint; 2) Two-step brazing with Ti-Zr-Cu-Ni filler and Nb interlayer, which regulated the formation of the brittle intermetallic compounds and residual stress, produced a crack-free brazed joint.
{"title":"Two routes to produce robust Mo-14Re/inconel 625 brazed joint: Microstructure and mechanical performance","authors":"Yanming He , Suqing Yao , Jialong Nie , Jiabing Liang , Huaxin Li , Lei Shi , Yuan Sun , Shengxuan Yang , Weijiang Guo , Chuanyang Lu , Jianguo Yang , Yafei Li","doi":"10.1016/j.vacuum.2025.114051","DOIUrl":"10.1016/j.vacuum.2025.114051","url":null,"abstract":"<div><div>The Mo-14Re/Inconel 625 alloy joint brazed using traditional BNi-2 or Cu interlayers generally exhibited unsatisfactory bonding strength and cracks due to a large mismatch of coefficient of thermal expansion (CTE) between the base materials. In this study, Mo-14Re and Inconel 625 were brazed using two routes: 1) One-step brazing with Au-Ni paste achieved a shear strength up to 547.9 MPa, due to the predominance of high-strength and ductile Au(s,s) in the brazed joint; 2) Two-step brazing with Ti-Zr-Cu-Ni filler and Nb interlayer, which regulated the formation of the brittle intermetallic compounds and residual stress, produced a crack-free brazed joint.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"234 ","pages":"Article 114051"},"PeriodicalIF":3.8,"publicationDate":"2025-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143205540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-18DOI: 10.1016/j.vacuum.2025.114038
Masanari Namie , Jun-ichi Saito , Ryotaro Oka , Jae-Ho Kim
Wettability of titanium (Ti) and surface-modified (Oxidized or Fluorinated) Ti with liquid sodium (Na) were investigated via experiments and theoretical calculations. From the experimental results, a sliding angle of Na droplet on oxidized Ti was smaller than that on untreated Ti, indicating the worsening of wettability by oxidation. In contrast, the sliding angle of Na droplet on fluoridated Ti was larger than that on untreated Ti, indicating an improvement in wettability by fluorination. Additionally, the cluster models for the interface between Na droplets and treated or untreated Ti were constructed for theoretical calculations of electronic states at the interface, covalent and ionic bonds at the interface were evaluated from the calculation results. The sliding angles obtained in the wettability tests and the strength of covalent bonding at the interface showed no correlation, but good correlation was observed between the sliding angles and ionic bonding at the interface. Thus, the wettability of surface-modified Ti with liquid Na can be theoretically understood based on the atomic interactions at the interface.
{"title":"Electronic approach to understand the wettability of surface treated titanium with liquid sodium","authors":"Masanari Namie , Jun-ichi Saito , Ryotaro Oka , Jae-Ho Kim","doi":"10.1016/j.vacuum.2025.114038","DOIUrl":"10.1016/j.vacuum.2025.114038","url":null,"abstract":"<div><div>Wettability of titanium (Ti) and surface-modified (Oxidized or Fluorinated) Ti with liquid sodium (Na) were investigated via experiments and theoretical calculations. From the experimental results, a sliding angle of Na droplet on oxidized Ti was smaller than that on untreated Ti, indicating the worsening of wettability by oxidation. In contrast, the sliding angle of Na droplet on fluoridated Ti was larger than that on untreated Ti, indicating an improvement in wettability by fluorination. Additionally, the cluster models for the interface between Na droplets and treated or untreated Ti were constructed for theoretical calculations of electronic states at the interface, covalent and ionic bonds at the interface were evaluated from the calculation results. The sliding angles obtained in the wettability tests and the strength of covalent bonding at the interface showed no correlation, but good correlation was observed between the sliding angles and ionic bonding at the interface. Thus, the wettability of surface-modified Ti with liquid Na can be theoretically understood based on the atomic interactions at the interface.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"234 ","pages":"Article 114038"},"PeriodicalIF":3.8,"publicationDate":"2025-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143351619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-18DOI: 10.1016/j.vacuum.2025.114050
Shen Yang, Zhiyong Hu, Jinkai Xu, Xuewen Sun, Yan Wang
In present study, the Zircaloy-4 was subjected to a composite surface modification induced by a micro electrical discharge machining (μEDM) device and a high current pulsed electron beam (HCPEB) device. The results showed that after μEDM-HCPEB composite action (using the μEDM device for main cutting and 7 times of trimming, followed by 25 times surface irradiation with the HCPEB device), the sample surface became extremely flat and compact, and Cu alloying was successfully achieved. The alloying layer featured significant refinement of grains and martensites, along with the formation of extensive areas consisting of nanocrystalline grains. Also in this layer, except for most Cu atoms that being uniformly dissolved in the matrix, some others together with Fe and Cr atoms formed a few Zr(Fe, Cr, Cu)2 second phase particles (SPPs) which sizes were smaller than 20 nm. On the contrary, large-sized Zr(Fe, Cr)2 SPPs with a size range of 100–250 nm that originally existed in the matrix dissolved throughout the remelted layer and the heat-affected zone. Corrosion behavior test was conducted in 500 °C/10.3 MPa superheated steam, and the results indicated that the aforementioned surface microstructural changes endowed the 7-trimmed+25-pulsed sample with extremely excellent corrosion resistance.
{"title":"Surface microstructures and corrosion behavior of Zircaloy-4 induced by the composite action of micro electrical discharge machining and high current pulsed electron beam","authors":"Shen Yang, Zhiyong Hu, Jinkai Xu, Xuewen Sun, Yan Wang","doi":"10.1016/j.vacuum.2025.114050","DOIUrl":"10.1016/j.vacuum.2025.114050","url":null,"abstract":"<div><div>In present study, the Zircaloy-4 was subjected to a composite surface modification induced by a micro electrical discharge machining (μEDM) device and a high current pulsed electron beam (HCPEB) device. The results showed that after μEDM-HCPEB composite action (using the μEDM device for main cutting and 7 times of trimming, followed by 25 times surface irradiation with the HCPEB device), the sample surface became extremely flat and compact, and Cu alloying was successfully achieved. The alloying layer featured significant refinement of grains and martensites, along with the formation of extensive areas consisting of nanocrystalline grains. Also in this layer, except for most Cu atoms that being uniformly dissolved in the matrix, some others together with Fe and Cr atoms formed a few Zr(Fe, Cr, Cu)<sub>2</sub> second phase particles (SPPs) which sizes were smaller than 20 nm. On the contrary, large-sized Zr(Fe, Cr)<sub>2</sub> SPPs with a size range of 100–250 nm that originally existed in the matrix dissolved throughout the remelted layer and the heat-affected zone. Corrosion behavior test was conducted in 500 °C/10.3 MPa superheated steam, and the results indicated that the aforementioned surface microstructural changes endowed the 7-trimmed+25-pulsed sample with extremely excellent corrosion resistance.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"234 ","pages":"Article 114050"},"PeriodicalIF":3.8,"publicationDate":"2025-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143205669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-18DOI: 10.1016/j.vacuum.2025.114045
S. Misdanitis, N. Vasileiadis , D. Valougeorgis
Gas distribution systems operating under any vacuum conditions are critical in technologies such as semiconductor manufacturing, microfluidics, vacuum metallurgy and nuclear fusion. Typical hydrodynamic models fail to predict gas behavior accurately across the wide range of rarefaction conditions encountered in these systems, necessitating computationally intensive mesoscale kinetic modeling. This type of networks may be efficiently simulated by in-house codes, such as ARIADNE, which combines a network solver with a kinetic database of the flow rates of rarefied gas flow through capillaries.
Here, ARIADNE is further enhanced by substituting the flow rates kinetic database with corresponding closed-form expressions, obtained by machine learning techniques, namely symbolic regression (SR). SR expressions, which have been deduced for flows through single pipe elements, are directly incorporated into the network solver and the need of the kinetic database is eliminated. The upgraded code is successfully validated by solving three benchmark gas distribution systems: two moderate scale networks and a very large one representing the primary vacuum system of the ITER fusion reactor. The presented results demonstrate the capability and robustness of the enhanced ARIADΝE code, named ARIADNE-ML, to accurately simulate vacuum systems of arbitrary size and complexity. Since there is no data dependency, the solver becomes more flexible, applicable and scalable across more complex systems without worrying about query bottlenecks, broadening its use in engineering and industrial applications.
{"title":"Machine learning aided simulation of gas distribution systems operating under any vacuum conditions","authors":"S. Misdanitis, N. Vasileiadis , D. Valougeorgis","doi":"10.1016/j.vacuum.2025.114045","DOIUrl":"10.1016/j.vacuum.2025.114045","url":null,"abstract":"<div><div>Gas distribution systems operating under any vacuum conditions are critical in technologies such as semiconductor manufacturing, microfluidics, vacuum metallurgy and nuclear fusion. Typical hydrodynamic models fail to predict gas behavior accurately across the wide range of rarefaction conditions encountered in these systems, necessitating computationally intensive mesoscale kinetic modeling. This type of networks may be efficiently simulated by in-house codes, such as ARIADNE, which combines a network solver with a kinetic database of the flow rates of rarefied gas flow through capillaries.</div><div>Here, ARIADNE is further enhanced by substituting the flow rates kinetic database with corresponding closed-form expressions, obtained by machine learning techniques, namely symbolic regression (SR). SR expressions, which have been deduced for flows through single pipe elements, are directly incorporated into the network solver and the need of the kinetic database is eliminated. The upgraded code is successfully validated by solving three benchmark gas distribution systems: two moderate scale networks and a very large one representing the primary vacuum system of the ITER fusion reactor. The presented results demonstrate the capability and robustness of the enhanced ARIADΝE code, named ARIADNE-ML, to accurately simulate vacuum systems of arbitrary size and complexity. Since there is no data dependency, the solver becomes more flexible, applicable and scalable across more complex systems without worrying about query bottlenecks, broadening its use in engineering and industrial applications.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"234 ","pages":"Article 114045"},"PeriodicalIF":3.8,"publicationDate":"2025-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143351621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The high Nb-TiAl alloy is subjected to lower temperature and shorter time hot compression treatment in this study, and it is found that the B2 phase precipitated from the metastable phase. The analysis shows that under the action of stress and temperature, due to the different diffusion velocity of Ti, Al and Nb atoms, the diffusion of Ti and Nb atoms is slower and the diffusion of Al atom is faster, which leads to the enrichment of Ti and Nb atoms and formation B2 phase. In the whole process, stress can promote the movement of dislocations, thereby accelerating the diffusion of atoms.
{"title":"B2 phase precipitation behavior in high-Nb TiAl alloy under lower temperature and shorter time with compression stress","authors":"Yiyuan Chang , Shulin Dong , Shibing Liu , Yingdong Qu , Ruirun Chen , Guanglong Li , Wei Zhang , Siruo Zhang","doi":"10.1016/j.vacuum.2025.114046","DOIUrl":"10.1016/j.vacuum.2025.114046","url":null,"abstract":"<div><div>The high Nb-TiAl alloy is subjected to lower temperature and shorter time hot compression treatment in this study, and it is found that the B2 phase precipitated from the metastable phase. The analysis shows that under the action of stress and temperature, due to the different diffusion velocity of Ti, Al and Nb atoms, the diffusion of Ti and Nb atoms is slower and the diffusion of Al atom is faster, which leads to the enrichment of Ti and Nb atoms and formation B2 phase. In the whole process, stress can promote the movement of dislocations, thereby accelerating the diffusion of atoms.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"233 ","pages":"Article 114046"},"PeriodicalIF":3.8,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143158257","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-13DOI: 10.1016/j.vacuum.2025.114036
Liwang Zhang , Caiju Li , Zunyan Xu , Liyuan Liu , Li Fu , Peng Gao , Qiong Lu , Jingmei Tao , Rui Bao , Jianhong Yi
The CrMnFeCoNi high-entropy alloy faces limitations in engineering applications due to insufficient room-temperature strength and a suboptimal strength-ductility synergy. This research tackles these limitations by incorporating nano-SiC particles and refining the processing techniques to create a bimodal grain structure. This approach facilitates micro-nano reinforcements and successfully prevents the development of brittle phases. Consequently, the alloy exhibits a yield strength of 595.89 MPa, tensile strength of 891.92 MPa, and an elongation of 10.34 %. Dynamic Hall-Petch effects and twinning-induced plasticity are activated during deformation, facilitating concurrent enhancement of strength and ductility.
{"title":"Balancing the strength and ductility of nano-SiC reinforced CrMnFeCoNi high-entropy alloy through designing bimodal grains and micro-nano reinforcements","authors":"Liwang Zhang , Caiju Li , Zunyan Xu , Liyuan Liu , Li Fu , Peng Gao , Qiong Lu , Jingmei Tao , Rui Bao , Jianhong Yi","doi":"10.1016/j.vacuum.2025.114036","DOIUrl":"10.1016/j.vacuum.2025.114036","url":null,"abstract":"<div><div>The CrMnFeCoNi high-entropy alloy faces limitations in engineering applications due to insufficient room-temperature strength and a suboptimal strength-ductility synergy. This research tackles these limitations by incorporating nano-SiC particles and refining the processing techniques to create a bimodal grain structure. This approach facilitates micro-nano reinforcements and successfully prevents the development of brittle phases. Consequently, the alloy exhibits a yield strength of 595.89 MPa, tensile strength of 891.92 MPa, and an elongation of 10.34 %. Dynamic Hall-Petch effects and twinning-induced plasticity are activated during deformation, facilitating concurrent enhancement of strength and ductility.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"233 ","pages":"Article 114036"},"PeriodicalIF":3.8,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143158258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-12DOI: 10.1016/j.vacuum.2025.114033
Evan T. Ostrowski, Zihan Lin, Bruce E. Koel
The thermal stability of thin Li films (≤7 nm) on a polycrystalline W substrate is reported in the temperature range of 300–1800 K to advance understanding of Li plasma-facing components (PFCs) in fusion devices. High steady-state and transient heat loads on the PFCs of fusion devices can yield surface temperatures exceeding 2200 K, so the thermal stability of Li in proposed Li-W hybrid PFCs requires testing for potential “dry-out” conditions at such high temperatures. Li films were deposited on a polycrystalline W foil in ultrahigh vacuum conditions, and their thermal stability was probed with a combination of temperature programmed desorption (TPD), low-energy ion scattering (LEIS), and X-ray photoelectron spectroscopy (XPS). With TPD, Li desorption became measurable starting at 460 K, and Li did not fully desorb from the W substrate until 1125–1200 K. LEIS and XPS results agreed with the findings from TPD. At 455 K, increased surface diffusion of Li was indicated by the XPS results before the onset of Li multilayer desorption. This investigation of the thermal stability of high-purity Li thin films on a clean, W-based substrate will inform design, operation, and performance of future hybrid PFC systems with liquid Li on a solid W substrate.
{"title":"Thermal stability of Li films on a polycrystalline W substrate","authors":"Evan T. Ostrowski, Zihan Lin, Bruce E. Koel","doi":"10.1016/j.vacuum.2025.114033","DOIUrl":"10.1016/j.vacuum.2025.114033","url":null,"abstract":"<div><div>The thermal stability of thin Li films (≤7 nm) on a polycrystalline W substrate is reported in the temperature range of 300–1800 K to advance understanding of Li plasma-facing components (PFCs) in fusion devices. High steady-state and transient heat loads on the PFCs of fusion devices can yield surface temperatures exceeding 2200 K, so the thermal stability of Li in proposed Li-W hybrid PFCs requires testing for potential “dry-out” conditions at such high temperatures. Li films were deposited on a polycrystalline W foil in ultrahigh vacuum conditions, and their thermal stability was probed with a combination of temperature programmed desorption (TPD), low-energy ion scattering (LEIS), and X-ray photoelectron spectroscopy (XPS). With TPD, Li desorption became measurable starting at 460 K, and Li did not fully desorb from the W substrate until 1125–1200 K. LEIS and XPS results agreed with the findings from TPD. At 455 K, increased surface diffusion of Li was indicated by the XPS results before the onset of Li multilayer desorption. This investigation of the thermal stability of high-purity Li thin films on a clean, W-based substrate will inform design, operation, and performance of future hybrid PFC systems with liquid Li on a solid W substrate.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"234 ","pages":"Article 114033"},"PeriodicalIF":3.8,"publicationDate":"2025-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143206014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-10DOI: 10.1016/j.vacuum.2025.114028
Hao Wang, Yihao Tang, Hongpu Yue, Zibo Zhao, Tianxiang Gao, Fengchao An, Xinyu Zhang, Riping Liu
In this work, a typical heterostructure for a Fe-Mn-Al-C-based austenitic steel is processed by a simple cold-rolling process. As cold-rolling strain increasing (20 %→80 %), the steel exhibits an increasing in the dislocations and shear bands, accompanied by a reduction in the fraction of the region with low dislocation density. This suggests that a heterogeneous structure characterized by dislocation density, i.e., hard regions with high dislocation density (24 % in area) and soft regions with low dislocation density (76 % in area), was designed in the steel with a reduction of ∼20 %. This heterogeneity triggers additional strengthening and strain hardening mechanisms, thereby enhancing the strength-ductility synergy (yield strength: 1266 MPa, ultimate tensile strength: 1415 MPa, and fracture elongation: 29 %). This cold-rolling strain-induced heterostructure offers a promising and cost-effective avenue for the development of Fe-Mn-Al-C steels with superior strength-ductility balance.
{"title":"Improvement of strength-ductility balance of Fe-Mn-Al-C-based austenitic steel via tuning rolling strain","authors":"Hao Wang, Yihao Tang, Hongpu Yue, Zibo Zhao, Tianxiang Gao, Fengchao An, Xinyu Zhang, Riping Liu","doi":"10.1016/j.vacuum.2025.114028","DOIUrl":"10.1016/j.vacuum.2025.114028","url":null,"abstract":"<div><div>In this work, a typical heterostructure for a Fe-Mn-Al-C-based austenitic steel is processed by a simple cold-rolling process. As cold-rolling strain increasing (20 %→80 %), the steel exhibits an increasing in the dislocations and shear bands, accompanied by a reduction in the fraction of the region with low dislocation density. This suggests that a heterogeneous structure characterized by dislocation density, i.e., hard regions with high dislocation density (24 % in area) and soft regions with low dislocation density (76 % in area), was designed in the steel with a reduction of ∼20 %. This heterogeneity triggers additional strengthening and strain hardening mechanisms, thereby enhancing the strength-ductility synergy (yield strength: 1266 MPa, ultimate tensile strength: 1415 MPa, and fracture elongation: 29 %). This cold-rolling strain-induced heterostructure offers a promising and cost-effective avenue for the development of Fe-Mn-Al-C steels with superior strength-ductility balance.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"233 ","pages":"Article 114028"},"PeriodicalIF":3.8,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143158851","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-10DOI: 10.1016/j.vacuum.2024.114006
C. Zhao , S.M. Lambrick , N.A. von Jeinsen , Y. Yuan , X. Zhang , A. Radić , D.J. Ward , J. Ellis , A.P. Jardine
Scanning helium microscopy (SHeM) is an emerging technique that uses a beam of neutral atoms to image and analyse surfaces. The low energies (64 meV) and completely non-destructive nature of the probe particles provide exceptional sensitivity for studying delicate samples and thin devices, including 2D materials. To date, around five such instruments have been constructed and are described in the literature. All represent the first attempts at SHeM construction in different laboratories, and use a single detection device. Here, we describe our second generation microscope, which is the first to offer multi-detector capabilities. The new instrument builds on recent research into SHeM optimisation and incorporates many improved design features over our previous instrument. We present measurements that highlight some of the unique capabilities the instrument provides, including 3D surface profiling, alternative imaging modes, and simultaneous acquisition of images from a mixed species beam.
{"title":"A multi-detector neutral helium atom microscope","authors":"C. Zhao , S.M. Lambrick , N.A. von Jeinsen , Y. Yuan , X. Zhang , A. Radić , D.J. Ward , J. Ellis , A.P. Jardine","doi":"10.1016/j.vacuum.2024.114006","DOIUrl":"10.1016/j.vacuum.2024.114006","url":null,"abstract":"<div><div>Scanning helium microscopy (SHeM) is an emerging technique that uses a beam of neutral atoms to image and analyse surfaces. The low energies (<span><math><mo>∼</mo></math></span>64 meV) and completely non-destructive nature of the probe particles provide exceptional sensitivity for studying delicate samples and thin devices, including 2D materials. To date, around five such instruments have been constructed and are described in the literature. All represent the first attempts at SHeM construction in different laboratories, and use a single detection device. Here, we describe our second generation microscope, which is the first to offer multi-detector capabilities. The new instrument builds on recent research into SHeM optimisation and incorporates many improved design features over our previous instrument. We present measurements that highlight some of the unique capabilities the instrument provides, including 3D surface profiling, alternative imaging modes, and simultaneous acquisition of images from a mixed species beam.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"234 ","pages":"Article 114006"},"PeriodicalIF":3.8,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143205563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-07DOI: 10.1016/j.vacuum.2025.114023
Dian Ayu Setyorini , Muhamad Allan Serunting , Wa Ode Sri Rizki , Nandang Mufti , Vienna Saraswaty , Muhammad Aziz , Risa Suryana , Wilman Septina , Zulhadjri , Henry Setiyanto
Carbon quantum dots (CQD) have been acknowledged as novel carbon-based materials with distinctive optical properties and excellent performance for detecting cadmium ion (Cd2+). Herein we report a facile synthesis of CQD from a natural source that is Archidendron bubalinum pods (CQDAb) and its application for an electroanalysis of Cd2+. The synthesized CQDAb was found emitting a strong blue fluorescence. Moreover, the synthesized CQDAb showed lower band gap (4.04 eV) than that of CQD synthesized from graphite (6.09 eV). For electroanalysis purposes, the CQDAb was used as a modifier for carbon paste electrode-based reduced-graphene oxide (CPE/r-GO/CQDAb). The composite of rGO/CQDAb could enhance the performance of CPE/CQDAb and CPE/rGO. The prepared CPE/rGO/CQDAb shows a greater linearity for Cd2+ detection when tested using a square wave voltammetry method. These findings clearly show promising results for preparing CQD-based natural source, specifically A. bubalinum pods, and its application for a Cd2+ sensor.
{"title":"Synthesis of carbon quantum dots (CQD) from Archidendron bubalinum pods and its compatibility for voltammetric detection of cadmium ion","authors":"Dian Ayu Setyorini , Muhamad Allan Serunting , Wa Ode Sri Rizki , Nandang Mufti , Vienna Saraswaty , Muhammad Aziz , Risa Suryana , Wilman Septina , Zulhadjri , Henry Setiyanto","doi":"10.1016/j.vacuum.2025.114023","DOIUrl":"10.1016/j.vacuum.2025.114023","url":null,"abstract":"<div><div>Carbon quantum dots (CQD) have been acknowledged as novel carbon-based materials with distinctive optical properties and excellent performance for detecting cadmium ion (Cd<sup>2+</sup>). Herein we report a facile synthesis of CQD from a natural source that is <em>Archidendron bubalinum</em> pods (CQD<em>Ab</em>) and its application for an electroanalysis of Cd<sup>2+</sup>. The synthesized CQD<em>Ab</em> was found emitting a strong blue fluorescence. Moreover, the synthesized CQD<em>Ab</em> showed lower band gap (4.04 eV) than that of CQD synthesized from graphite (6.09 eV). For electroanalysis purposes, the CQD<em>Ab</em> was used as a modifier for carbon paste electrode-based reduced-graphene oxide (CPE/r-GO/CQD<em>Ab</em>). The composite of rGO/CQD<em>Ab</em> could enhance the performance of CPE/CQD<em>Ab</em> and CPE/rGO. The prepared CPE/rGO/CQD<em>Ab</em> shows a greater linearity for Cd<sup>2+</sup> detection when tested using a square wave voltammetry method. These findings clearly show promising results for preparing CQD-based natural source, specifically <em>A. bubalinum</em> pods, and its application for a Cd<sup>2+</sup> sensor.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"233 ","pages":"Article 114023"},"PeriodicalIF":3.8,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143158260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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