Vacuum最新文献 - Book学术

Significantly improved crystallinity in Cu2O films enabled by heteroepitaxy on abnormally-grown Ag templates 通过异质外延在异常生长的Ag模板上，显著提高了Cu2O薄膜的结晶度

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-10-09 DOI: 10.1016/j.vacuum.2025.114815

Peisen Liu, Jiangyiming Jiang, Yun Tian

{"title":"Significantly improved crystallinity in Cu2O films enabled by heteroepitaxy on abnormally-grown Ag templates","authors":"Peisen Liu, Jiangyiming Jiang, Yun Tian","doi":"10.1016/j.vacuum.2025.114815","DOIUrl":"10.1016/j.vacuum.2025.114815","url":null,"abstract":"<div><div>Cuprous oxide (Cu<sub>2</sub>O) is a promising p-type absorber in thin film heterojunction solar cells due to its non-toxic, low-cost processing and high theoretical power conversion efficiency (PCE). However, conventional synthesis methods yield Cu<sub>2</sub>O films with small grains and numerous grain boundaries that act as charge recombination centers, severely limiting device performance. Strategies to enlarge grains require high-temperature processes (>600 °C) with increased production costs, or involve complex epitaxial growth of Cu<sub>2</sub>O films on non-conductive substrates. In this work, abnormally-grown Ag films with large grains were used as the templates for epitaxial growth of Cu<sub>2</sub>O films. Grain size as large as ∼10 μm can be obtained in Cu<sub>2</sub>O films epitaxially deposited on Ag templates. It is revealed that a composition-transition buffer layer formed at the Cu<sub>2</sub>O/Ag interface reduces lattice mismatch and facilitates epitaxy. The photoluminescence spectra (PL) of epitaxially grown Cu<sub>2</sub>O films showed extremely high near band-edge luminescence intensity, demonstrating the significantly improved crystallinity for epitaxially grown Cu<sub>2</sub>O films on Ag templates. This work suggests that epitaxial growth of Cu<sub>2</sub>O films on abnormally-grown Ag templates is an effective method to improve the crystallinity of Cu<sub>2</sub>O thin films with a low thermal budget.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"243 ","pages":"Article 114815"},"PeriodicalIF":3.9,"publicationDate":"2025-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145270011","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}

引用次数: 0

Editorial Board and Vacuum units 编辑委员会和真空单位

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-10-09 DOI: 10.1016/S0042-207X(25)00790-0

引用次数: 0

Catalytic mechanisms and contamination effects of metal catalysts in the direct growth of graphene on silicon substrates 石墨烯在硅衬底上直接生长的金属催化剂的催化机理和污染效应

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-10-06 DOI: 10.1016/j.vacuum.2025.114810

Ning Hou , Ruiqi Zhang , Shenghui Hou , Huawen Wang , Hao Jiang , Xu Chen , Jie Yu , Xin Xu , Xin Li

{"title":"Catalytic mechanisms and contamination effects of metal catalysts in the direct growth of graphene on silicon substrates","authors":"Ning Hou , Ruiqi Zhang , Shenghui Hou , Huawen Wang , Hao Jiang , Xu Chen , Jie Yu , Xin Xu , Xin Li","doi":"10.1016/j.vacuum.2025.114810","DOIUrl":"10.1016/j.vacuum.2025.114810","url":null,"abstract":"<div><div>Direct growth of graphene films on non-catalytic substrates, such as silicon (Si), remains challenging due to the absence of catalytic activity for carbon source decomposition. The additional metal catalysts were introduced to overcome this limitation, their vapor pressure and catalytic ability could strongly affect the catalytic efficiency and impurity level of fabricated graphene films. In this study, the catalytic mechanisms and contamination effects of different catalysts in the direct growth of graphene on Si substrates by CVD were investigated. Methane decomposition process occurred on the catalysis surface was calculated with volumetric methane concentration model, while carbon radical diffusion process in the CVD chamber was simulated by FEA Multiphysics Modelling. The predicted methane decomposition efficiencies were approximately 100 %, 0.48 %, and 0.08 % for Ni, Cu, and Ga foils under 300 sccm carrier gas at atmosphere, respectively. The results indicated Ni catalyst exhibited the highest methane decomposition efficiency. Graphene synthesized with the Ni catalyst exhibited good crystallinity, low defect density, and low sheet resistance. XPS analysis indicated the absence of catalyst contamination under Ni catalyzation, while SEM-EDS re-confirmed no detectable Ni contamination in the fabricated graphene. In contrast graphene grown with Cu or Ga catalysts exhibited obvious metal contamination. Our work suggested that metal with high catalytic ability and low vapor pressure will be more favourable for uniform, good crystallinity and non-contamination graphene films directly growth on silicon substrate.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"243 ","pages":"Article 114810"},"PeriodicalIF":3.9,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145270003","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}

引用次数: 0

Influence of opening velocity on interruption capacity of intermediate-frequency vacuum switches with consideration of metal vapor density 考虑金属蒸气密度时开启速度对中频真空开关中断能力的影响

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-10-06 DOI: 10.1016/j.vacuum.2025.114809

Shangwen Xia , Jianwen Wu , Jingyi Lin , Ruang Chen , Yuan Jiang

{"title":"Influence of opening velocity on interruption capacity of intermediate-frequency vacuum switches with consideration of metal vapor density","authors":"Shangwen Xia , Jianwen Wu , Jingyi Lin , Ruang Chen , Yuan Jiang","doi":"10.1016/j.vacuum.2025.114809","DOIUrl":"10.1016/j.vacuum.2025.114809","url":null,"abstract":"<div><div>The interruption capacity of intermediate-frequency (IF) vacuum switches is significantly affected by contact opening velocity and metal vapor density. However, systematic experimental validation of their interaction mechanisms remains limited. In this study, a dedicated IF drawn-arc platform is developed, and interruption experiments are conducted at 4–14 kA RMS under three distinct opening speeds. A transient numerical model is established to compute the metal vapor density at the current zero point (CZP). Based on experimental measurements and numerical modeling, the metal vapor density at CZP is quantitatively analyzes as a function of opening speed and frequency, and critical opening speed configurations are proposed to ensure safe interruption in IF systems. A map of opening speed, current, and frequency was constructed using the critical vapor density criterion, and the calculated safety margins were in good agreement with experimental results. For a 20 mm diameter CuCr25 flat contact, the required speed increases from 0.44 m/s at 360 Hz to approximately 2.20 m/s at 800 Hz for 10 kA RMS interruption. This study establishes that opening velocity governs interruption performance by controlling metal vapor density, thereby providing both a predictive framework for contact velocity design and a quantitative basis for optimizing aviation IF vacuum switches.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"243 ","pages":"Article 114809"},"PeriodicalIF":3.9,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145270007","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}

引用次数: 0

First-principles investigation of structural stability, mechanical and thermal properties of TiRM3 (RM = Cr, Mo, and W) compounds TiRM3 （RM = Cr， Mo和W）化合物结构稳定性、力学和热性能的第一性原理研究

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-10-06 DOI: 10.1016/j.vacuum.2025.114808

Taimin Cheng, Yanwen Liu, Xinxin Zhang, Guoliang Yu

{"title":"First-principles investigation of structural stability, mechanical and thermal properties of TiRM3 (RM = Cr, Mo, and W) compounds","authors":"Taimin Cheng, Yanwen Liu, Xinxin Zhang, Guoliang Yu","doi":"10.1016/j.vacuum.2025.114808","DOIUrl":"10.1016/j.vacuum.2025.114808","url":null,"abstract":"<div><div>This work presents first-principles calculations of the physical properties of cubic (<em>Fm</em> <span><math><mrow><mover><mn>3</mn><mo>‾</mo></mover></mrow></math></span> <em>m</em>) and orthorhombic (<em>Immm</em>) TiRM<sub>3</sub> (RM = Cr, Mo and W) compounds, with a particular focus on their mechanical and thermal properties. The structural stability is assessed by the enthalpy of formation Δ<em>H</em>, elastic constants, and phonon spectrum. The TiCr<sub>3</sub>, with positive Δ<em>H</em> greater than 0.01 eV/atom, may be metastable, while the TiMo<sub>3</sub> and TiW<sub>3</sub> compounds, with negative Δ<em>H</em> less than −0.05 eV/atom, are ground-state stable. From TiCr<sub>3</sub>, TiMo<sub>3</sub> to TiW<sub>3</sub>, the elastic modulus as well as the isothermal bulk modulus at finite temperature is enhanced, while the volumetric thermal expansion coefficient, elastic/thermal-expansion anisotropy are weakened. Furthermore, a comparative analysis with pure <em>bcc</em>-RM is conducted. All TiRM<sub>3</sub> compounds exhibit excellent ductility, which is superior to that of their <em>bcc</em>-RM counterparts, however, the elastic modulus is inferior. The volumetric thermal expansion coefficients of the TiRM<sub>3</sub> compounds are higher than that of the pure <em>bcc</em>-RM metal. The selection and evaluation of materials for use in nuclear fusion should benefit from these theoretical insights.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"243 ","pages":"Article 114808"},"PeriodicalIF":3.9,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145270004","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}

引用次数: 0

Green synthesis of CaO-modified sulfonated biochar via ball milling method 球磨法绿色合成cao改性磺化生物炭

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-10-06 DOI: 10.1016/j.vacuum.2025.114795

Sarah Pratiwi , Latifah Hauli , Dieni Mansur , Vivi Sisca , Arief Budiman

{"title":"Green synthesis of CaO-modified sulfonated biochar via ball milling method","authors":"Sarah Pratiwi , Latifah Hauli , Dieni Mansur , Vivi Sisca , Arief Budiman","doi":"10.1016/j.vacuum.2025.114795","DOIUrl":"10.1016/j.vacuum.2025.114795","url":null,"abstract":"<div><div>The main objective of this research was to produce the sulfonated biochar (SB) modified by CaO using the ball milling method and investigate the physical and chemical properties of the obtained material (SB/CaO). In this study, p-Toluene sulfonic acid (p-TSA) was utilized as the sulfonating agent. The sulfonation process was conducted on activated biochar (B) with various weight ratios of B to p-TSA (1:3; 3:1; and 1:1) to observe the acidity of the resulting SB. The SB/CaO was synthesized through the ball milling method with different proportions of CaO (30, 50, and 70 wt%), utilizing the formulation that yielded the highest acidity value of SB. The obtained material was characterized using NH<sub>3</sub>-TPD, CO<sub>2</sub>-TPD, XRF, FTIR, XPS, XRD, SEM-EDX, HRTEM and surface area analyzer. The results indicated that the highest acidity value of 4.08 mmol/g was achieved with the SB (1:3) ratio. The addition of CaO to SB resulted in an increase in basicity value and a decrease in acidity value. XRD analysis indicated a reduction in the crystallinity index % at the highest variations of CaO weight. Furthermore, the presence of CaO significantly influenced on the morphology of SB/CaO. The specific surface area of SB/CaO was observed to decrease with the increasing weight of CaO used. The study of the characteristics and properties of SB/CaO indicates its potential use in catalytic applications.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"243 ","pages":"Article 114795"},"PeriodicalIF":3.9,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145270009","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}

引用次数: 0

Evaluation of microstructural evolution of glassy carbon induced by helium implantation and annealing 氦注入退火诱导玻璃碳微观组织演变的评价

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-10-03 DOI: 10.1016/j.vacuum.2025.114796

C.E. Maepa , E.G. Njoroge , M.Y.A. Ismail , C. Dickinson , Z.A.Y. Abdalla , H.A.A. Abdelbagi , S.S. Ngongo , V. Maphiri , B.S. Li , T.T. Hlatshwayo

{"title":"Evaluation of microstructural evolution of glassy carbon induced by helium implantation and annealing","authors":"C.E. Maepa , E.G. Njoroge , M.Y.A. Ismail , C. Dickinson , Z.A.Y. Abdalla , H.A.A. Abdelbagi , S.S. Ngongo , V. Maphiri , B.S. Li , T.T. Hlatshwayo","doi":"10.1016/j.vacuum.2025.114796","DOIUrl":"10.1016/j.vacuum.2025.114796","url":null,"abstract":"<div><div>The effects of helium ion (He<sup>+2</sup>) implantation into glassy carbon (GC) were systematically investigated. He<sup>+2</sup> ions with an energy range of 17 keV were implanted into GC to fluences of 10<sup>16</sup>, 10<sup>17</sup> and 10<sup>18</sup> cm<sup>−2</sup> at room temperature (RT). The as-implanted GC samples were subsequently vacuum annealed at 300 °C, 500 °C, and 800 °C for 1 h. Structural evolution of GC was characterized using Raman spectroscopy and transmission electron microscopy (TEM). A fluence-dependent trend in displacement per atom (dpa) and He concentration was observed. Raman spectroscopy revealed progressive structural disorder and amorphization at fluences 10<sup>17</sup> and 10<sup>18</sup> cm<sup>−2</sup>, marked by merging and redshifts of the D and G peaks, indicating tensile strain in the carbon matrix. Partial recovery of D/G peak separation and crystalline order was observed, especially at 800 °C for the 10<sup>16</sup> cm<sup>−2</sup> fluence. TEM micrographs showed a confined damaged region of about 130 nm, with distinct defect aggregation towards the bulk for fluences of 10<sup>16</sup> cm<sup>−2</sup> and 10<sup>17</sup> cm<sup>−2</sup>, whereas the defect aggregation appeared in two regions for the fluences of 10<sup>18</sup> cm<sup>−2</sup>. At this high fluence, bubble-like structures were observed upon annealing, indicating He accumulation and pressurisation within the carbon matrix. This observation reveals a nonlinear dispersion and saturation effect. The bubbles contributed to the localized distribution of the lattice structure. Overall, annealing at 800 °C facilitated partial microstructural recovery, particularly for samples implanted to fluences of 10<sup>16</sup> cm<sup>−2</sup> and 10<sup>17</sup> cm<sup>−2</sup>.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"243 ","pages":"Article 114796"},"PeriodicalIF":3.9,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145270008","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}

引用次数: 0

Electrospun carbon nanofiber membranes for reinforcing YG8-GH3536 vacuum brazed joints 电纺碳纳米纤维膜增强YG8-GH3536真空钎焊接头

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-10-03 DOI: 10.1016/j.vacuum.2025.114793

Yiru Wang , Xinxin Feng , Hassaan Ahmad Butt , Zhi Qu , Manni Li , Zeyu Wang

{"title":"Electrospun carbon nanofiber membranes for reinforcing YG8-GH3536 vacuum brazed joints","authors":"Yiru Wang , Xinxin Feng , Hassaan Ahmad Butt , Zhi Qu , Manni Li , Zeyu Wang","doi":"10.1016/j.vacuum.2025.114793","DOIUrl":"10.1016/j.vacuum.2025.114793","url":null,"abstract":"<div><div>YG8 cemented carbide and GH3536 alloy vacuum brazed joints always suffer from high residual stress and poor toughness. To tackle this, we innovatively combined and employed electrospinning and carbonization to produce a carbon nanofiber (CNF) intermediate brazing interlayer membrane. The CNF interlayer effectively alleviated residual stresses and improved the overall mechanical performance of the joint. The morphology and crystallinity of the CNF membrane were characterized and correlated to effects on the microstructure and mechanical performance of the joint. Findings demonstrate that the CNF interlayer significantly reduced the amount of brittle intermetallic compounds in the braze seam, while increasing the proportion of Ag-Cu eutectic composition. The CNF framework remained intact after the brazing procedure and enhanced joint strength and toughness through load transfer and stress relief due to the fine and uniformly distributed porous microstructure. Compared to direct brazing without the CNF interlayer, the interlayer caused remarkable improvements: at room temperature, shear strength and fracture toughness increased by 43 % and 82 %, respectively, while at elevated temperature (400 °C), the corresponding enhancements reached 79 % and 263 %. In addition, finite-element analyses show that the residual stress in the joint could be markedly relieved after the introduction of an CNF interlayer due to its low coefficient of thermal expansion. This work provides an effective strategy for optimizing dissimilar material joints in extreme environments, particularly for space exploration applications.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"243 ","pages":"Article 114793"},"PeriodicalIF":3.9,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145270013","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}

引用次数: 0

Enhanced magnetic properties of grain-oriented Fe-3 wt.% Si steel sheet through water-jet guided laser processing 水射流激光加工增强晶粒取向fe - 3wt .% Si钢板的磁性能

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-10-02 DOI: 10.1016/j.vacuum.2025.114794

Rufan Chang , Zhen Wang , Hairui Zhao , Binbin Liu , Xiangju Shi , Shengzhi Sun , Feng Ye

引用次数: 0

Source tracing and diagnostic analysis of carbon erosion contaminants in hall thrusters based on spatiotemporal matrix-synchronized spectroscopy technology 基于时空矩阵同步光谱技术的霍尔推进器碳侵蚀污染物溯源与诊断分析

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-10-01 DOI: 10.1016/j.vacuum.2025.114779

Bo-Wen Zheng , Xi-Ming Zhu , Ren-Wei Zheng , Yang Zhao , Yong-Qi Kang , Da-Ren Yu

{"title":"Source tracing and diagnostic analysis of carbon erosion contaminants in hall thrusters based on spatiotemporal matrix-synchronized spectroscopy technology","authors":"Bo-Wen Zheng , Xi-Ming Zhu , Ren-Wei Zheng , Yang Zhao , Yong-Qi Kang , Da-Ren Yu","doi":"10.1016/j.vacuum.2025.114779","DOIUrl":"10.1016/j.vacuum.2025.114779","url":null,"abstract":"<div><div>Current research based on quartz crystal microbalance (QCM) measurements and theoretical simulations suggests that the carbon erosion contaminants observed in Hall thruster ground testing originates from the vacuum system walls and the magnetic poles of the Hall thruster. However, since QCM lack species discrimination capability, preventing direct validation of simulations and creating a gap in carbon source identification. To address this, this work employs optical emission spectroscopy, and develops a spatiotemporal matrix-synchronized spectroscopy technique. By acquiring real-time spatial distribution of carbon atoms, four distinct spatial distribution patterns were observed, indicating that the carbon source cannot be determined solely by spatial orientation. Further comparative analysis of carbon and boron spatial distributions revealed that carbon and boron share the same origin, confirming that the carbon stem from inner magnetic pole sputtering rather than vacuum system walls in this work. Using spatiotemporal matrix-synchronized spectroscopy monitoring system, this work obtained carbon atom spatial distribution data with temporal sequencing. This approach facilitates the online monitoring of erosion and transport evolution trends during Hall thruster wearing tests. By developing spatiotemporal matrix-synchronized spectroscopy, this work achieves source tracing of carbon erosion products, offering direct experimental data for analyzing wall effects in Hall thrusters and refining erosion-transport models.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"243 ","pages":"Article 114779"},"PeriodicalIF":3.9,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145270005","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}

引用次数: 0