IF 3.9 2区材料科学

Vacuum Pub Date : 2025-09-12 DOI: 10.1016/j.vacuum.2025.114736

Karna Wijaya , Devi Ariningtyas , Aldino Javier Saviola , Sri Sudiono , Moh. Adhib Ulil Absor , Won-Chun Oh , Kharistya Rozana , Wahyu Dita Saputri , Dita Adi Saputra , Mahendra Anggaravidya , Riska Astin Fitria , Eduard Christria Sambara

{"title":"Oxidative desulfurization of dibenzothiophene in model fuel using spray impregnated-biogenic silica-supported molybdenum oxide catalyst","authors":"Karna Wijaya , Devi Ariningtyas , Aldino Javier Saviola , Sri Sudiono , Moh. Adhib Ulil Absor , Won-Chun Oh , Kharistya Rozana , Wahyu Dita Saputri , Dita Adi Saputra , Mahendra Anggaravidya , Riska Astin Fitria , Eduard Christria Sambara","doi":"10.1016/j.vacuum.2025.114736","DOIUrl":"10.1016/j.vacuum.2025.114736","url":null,"abstract":"<div><div>The growing dependence on fossil fuels contributes to environmental degradation, particularly through sulfur-based emissions from compounds such as dibenzothiophene (DBT). This study presents an eco-friendly and cost-effective catalyst synthesized from agricultural waste. Silica derived from rice husk ash, induced with NaHCO<sub>3</sub>, was impregnated with molybdenum oxide (MoO<sub>3</sub>/SiO<sub>2</sub>) using a spray impregnation technique and applied in the oxidative desulfurization (ODS) of DBT using <em>n</em>-hexane as a model fuel. The dispersion of molybdenum oxide improved total acidity and DBT removal efficiency. Process optimization through response surface methodology with a central composite design (RSM–CCD) identified the optimal conditions as a reaction time of 32.12 min, an O/S molar ratio of 11.79, and a catalyst dosage of 3.20 wt%, yielding 96.71 % DBT removal. The catalyst also showed good reusability, maintaining 91.98 % efficiency after five cycles. These findings highlight the potential of MoO<sub>3</sub>/SiO<sub>2</sub> as a sustainable catalyst for cleaner industrial fuel production.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"242 ","pages":"Article 114736"},"PeriodicalIF":3.9,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145061063","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

High performance ring-type p-GaN AlGaN/GaN HEMTs using reactively sputtered NiNx gate 采用反应溅射NiNx栅的高性能环型p-GaN AlGaN/GaN hemt

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-09-12 DOI: 10.1016/j.vacuum.2025.114735

Mao Jia, Bin Hou, Ling Yang, Qian Xiao, Zhiqiang Xue, Meng Zhang, Mei Wu, Hao Lu, Xiaohua Ma, Yue Hao

{"title":"High performance ring-type p-GaN AlGaN/GaN HEMTs using reactively sputtered NiNx gate","authors":"Mao Jia, Bin Hou, Ling Yang, Qian Xiao, Zhiqiang Xue, Meng Zhang, Mei Wu, Hao Lu, Xiaohua Ma, Yue Hao","doi":"10.1016/j.vacuum.2025.114735","DOIUrl":"10.1016/j.vacuum.2025.114735","url":null,"abstract":"<div><div>This study demonstrates the superior performance of NiN<sub>x</sub>-gate <em>p</em>-GaN HEMTs fabricated through reactive magnetron sputtering of Ni in an Ar/N<sub>2</sub> atmosphere, achieving enhanced electrical characteristics and exceptional threshold voltage stability. The formation of NiN<sub>x</sub> was conclusively demonstrated through combined X-ray photoelectron spectroscopy and X-ray diffraction analyses. The cross-sectional STEM/EDX results for the NiN<sub>x</sub> gate metallization are also analyzed. The fabricated ring-type NiN<sub>x</sub>/<em>p</em>-GaN HEMTs exhibit excellent properties including a low on-resistance of 45.1 Ω mm and high gate breakdown voltage of 11 V at room temperature, significantly outperforming their Ni-gate counterparts (47.1 Ω mm and 8.6 V, respectively). Remarkable stability is evidenced by a minimal threshold voltage shift of just −0.94 mV during 5 V DC gate bias stress tests and an ultra-low Δ<em>V</em><sub>th</sub> of −0.1 V under 5 V pulsed gate stress. These results including maintained on-resistance, improved breakdown voltage, and outstanding <em>V</em><sub>th</sub> stability conclusively show that nitrogen incorporation during Ni sputtering represents an effective strategy for developing high-performance <em>p</em>-GaN HEMTs.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"242 ","pages":"Article 114735"},"PeriodicalIF":3.9,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145061064","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

Fabrication of flexible ZnO/TiC heterojunction composites and their field emission applications 柔性ZnO/TiC异质结复合材料的制备及其场发射应用

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-09-12 DOI: 10.1016/j.vacuum.2025.114733

Lei Sun , Zihao Lin , Changxiao Wang , Xin Chen , Lian Ma , Yongai Zhang

{"title":"Fabrication of flexible ZnO/TiC heterojunction composites and their field emission applications","authors":"Lei Sun , Zihao Lin , Changxiao Wang , Xin Chen , Lian Ma , Yongai Zhang","doi":"10.1016/j.vacuum.2025.114733","DOIUrl":"10.1016/j.vacuum.2025.114733","url":null,"abstract":"<div><div>Field emission holds significant promise for diverse applications in the field of vacuum microelectronic devices, and the development of flexible materials for high-performance field emission electron sources is of great value. In this study, ZnO/TiC nanorod arrays with the shell-core structure were constructed on the surface of flexible carbon fibers via magnetron sputtering. The composition and microstructure of the TiC film were precisely regulated by varying the carbon target power (50–80 W). Various characterization methods, such as XRD, SEM, EDS, and XPS, were applied to investigate the phase composition and morphology of ZnO/TiC composite structures. The results showed that the carbon target power had an important effect on the composition and microstructure of the TiC shell layer. The results show that the samples prepared with a carbon target power of 60 W exhibit optimal field emission performance, with low turn-on field strength (∼3.6 V/μm) and high field enhancement factors (∼2831), which are ascribed to the synergistic effects of the TiC shell layer's high crystallinity and good electrical conductivity, as well as the uniform diameters, optimized aspect ratios, and perpendicular orientations of the ZnO nanorods. This study provides a new idea for surface optimization of shell-chore nanostructured materials and lays the technical foundation for the development of high-performance flexible field emission microelectronic devices.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"242 ","pages":"Article 114733"},"PeriodicalIF":3.9,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145061061","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

A multi-stage temperature controlled vacuum distillation process for preparation of 4N selenium 多级温控真空精馏工艺制备4N硒

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-09-12 DOI: 10.1016/j.vacuum.2025.114727

Xuan Cui , Zhipeng Xu , Shuang Qiao , Shengnan Tang , Xueyi Guo , Qinghua Tian

{"title":"A multi-stage temperature controlled vacuum distillation process for preparation of 4N selenium","authors":"Xuan Cui , Zhipeng Xu , Shuang Qiao , Shengnan Tang , Xueyi Guo , Qinghua Tian","doi":"10.1016/j.vacuum.2025.114727","DOIUrl":"10.1016/j.vacuum.2025.114727","url":null,"abstract":"<div><div>High purity selenium serves as a critical functional material in semiconductor manufacturing, biomedicine, and optoelectronic applications, where its purity directly governs material performance and value. Herein, we report an eco-friendly multi-stage gradient temperature-controlled vacuum distillation process for high-purity selenium production. Crude selenium (99.52 % purity) underwent three-stage vacuum distillation under optimized conditions (distillation temperature: 743 K, condensation temperature: 423 K, holding time: 120 min, vacuum: 1–10 Pa), achieving a total impurity content of 45.51 ppmw and 4N5 selenium (99.995 % purity) with a total yield of 92.34 %. By manipulating impurity behaviors through segmented temperature gradients, the process selectively exploited sulfur's high volatility for preferential removal, suppressed tellurium's co-distillation via kinetic control, constrained arsenic's removal through dynamic equilibrium limitations, and retained low-volatility metals (Cu/Fe/Ni) in the residue, demonstrating impurity-specific removal efficiencies of 99.98 % (As), 99.93 % (Cu), 95.58 % (Te), 98.21 % (Fe), 77.45 % (S), and 95.56 % (Ni). This zero-chemical-reagent process eliminates resource consumption and pollution, outperforms conventional chemical-assisted methods in scalability and sustainability, and establishes a new pathway for green, high-throughput selenium purification with industrial-grade economic viability and environmental compliance.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"242 ","pages":"Article 114727"},"PeriodicalIF":3.9,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145105857","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

Research on design method of a novel axial vane pump based on structural innovation and its dynamic performance analysis 基于结构创新和动态性能分析的新型轴向叶片泵设计方法研究

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-09-11 DOI: 10.1016/j.vacuum.2025.114705

Zeling Zhao, Xinhua Wang, Zhen Zhang, Xinbo Yu, Shichao Fu, Tao Sun, Zisheng Guo, Shabir Ali

{"title":"Research on design method of a novel axial vane pump based on structural innovation and its dynamic performance analysis","authors":"Zeling Zhao, Xinhua Wang, Zhen Zhang, Xinbo Yu, Shichao Fu, Tao Sun, Zisheng Guo, Shabir Ali","doi":"10.1016/j.vacuum.2025.114705","DOIUrl":"10.1016/j.vacuum.2025.114705","url":null,"abstract":"<div><div>Vane pumps, characterized by high-efficiency, compact size, and high-pressure resistance, are widely utilized in petrochemical, aerospace, and other high-technology sectors. However, conventional radial vane pumps rely on centrifugal force to maintain vane-cam ring engagement, which inherently limits their performance under low rotational speeds. To address these limitations, this study proposes a novel axial vane pump design. Based on structural and dynamic analyses, a sinusoidal curve was selected as the reference profile for the stator's spiral. Three-dimensional (3D)-modeled key components were analyzed to validate the structural rationality of the proposed design. A prototype of the axial vane pump was fabricated, and an operational performance test system was established. Experimental results demonstrate that the pump maintains stable flow output across varying speeds, with a distinct linear relationship between flow rate and rotational speed. Wear analysis further reveals that enhancing the filtration system's purification capacity and maintaining lubricant medium stability are critical for extending equipment service life and improving operational reliability. This study provides a promising approach for the structural innovation and performance enhancement of vane pumps, offering valuable insights for future research and engineering applications.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"242 ","pages":"Article 114705"},"PeriodicalIF":3.9,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145061057","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

A novel method for visualizing vacuum black box: Simulation and experimental analyses on flow field of Pb-Ag alloy in vacuum distillation 真空黑箱可视化的新方法：真空蒸馏过程中铅银合金流场的模拟与实验分析

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-09-11 DOI: 10.1016/j.vacuum.2025.114734

Jiahao Dong , Jiapeng Zhang , Meiying Zhang , Lingxin Kong , Baoqiang Xu , Bin Yang , Yuxu Bao

{"title":"A novel method for visualizing vacuum black box: Simulation and experimental analyses on flow field of Pb-Ag alloy in vacuum distillation","authors":"Jiahao Dong , Jiapeng Zhang , Meiying Zhang , Lingxin Kong , Baoqiang Xu , Bin Yang , Yuxu Bao","doi":"10.1016/j.vacuum.2025.114734","DOIUrl":"10.1016/j.vacuum.2025.114734","url":null,"abstract":"<div><div>With the continuous reduction of mineral resources, it is imperative to recover Ag and Pb from secondary resources. Vacuum metallurgy is an important metal recovery method. The vacuum furnace is a ' black box ', and the flow field is blurred, which hinders the efficient extraction of metals. This study investigates Pb-Ag alloy distillation (1073–1273 K) through coupled simulations and experiments. The results show that the volatilization and condensation of metal vapor can be effectively simulated in the temperature range of this study. Simulations demonstrated strong agreement with experimental data, showing ≤12 % deviation in volatilization rates. The position of the condensation tray for collecting Pb can be quickly determined based on the simulation results, so as to collect more and purer Pb. The simulation model for flow field of alloy system established in this study is reliable and can be used to visualize vacuum furnace and guide the vacuum separation of alloys, thereby improving metal direct yield and purity. This method can be used to guide the development of new vacuum metallurgy technologies and equipment in industry, greatly reducing the number of experimental explorations, saving time, and reducing costs.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"242 ","pages":"Article 114734"},"PeriodicalIF":3.9,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145061060","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

A highly stretchable strain sensor fabricated based on freeze-thaw polymerized MXenes-doped hydrogel for monitoring human joint movement 基于冻融聚合掺mxenes水凝胶制备的高拉伸应变传感器用于监测人体关节运动

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-09-11 DOI: 10.1016/j.vacuum.2025.114738

Jie Zhang, Shaohui Zhang

引用次数: 0

Molecular dynamics simulation study on microscopic plastic deformation behavior of FCC AlCuMg alloy under laser shock peening FCC AlCuMg合金激光冲击强化微观塑性变形行为的分子动力学模拟研究

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-09-11 DOI: 10.1016/j.vacuum.2025.114737

H.T. Yang , W.N. Lu , J. Li

引用次数: 0

Investigation of ion instability exhibiting a broadband continuous spectrum in electron cyclotron resonance magnetic nozzle 电子回旋共振磁喷嘴中宽带连续谱离子不稳定性的研究

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-09-11 DOI: 10.1016/j.vacuum.2025.114717

Honghui Guo , Zhi Yang , Hongtao Liu , Yong Cao , Jinwei Bai , Yuan Hu

{"title":"Investigation of ion instability exhibiting a broadband continuous spectrum in electron cyclotron resonance magnetic nozzle","authors":"Honghui Guo , Zhi Yang , Hongtao Liu , Yong Cao , Jinwei Bai , Yuan Hu","doi":"10.1016/j.vacuum.2025.114717","DOIUrl":"10.1016/j.vacuum.2025.114717","url":null,"abstract":"<div><div>Instabilities in electron cyclotron resonance (ECR) magnetic nozzles are investigated through both theoretical analysis and experimental observation. An analytical dispersion relation for instabilities is derived using a two-fluid model. Experimentally, an instability measurement system employing fixed probe pairs is utilized to detect the presence of instabilities within the magnetic nozzle. Additionally, time-averaged plasma parameters inside the magnetic nozzle are measured for theoretical analysis of instabilities. By integrating the theoretical dispersion analysis with experimental instability measurements and plasma diagnostics, the influence of electromagnetic fields on the observed azimuthal instabilities is examined. The results reveal that the maximum growth rate (<span><math><msub><mrow><mi>γ</mi></mrow><mrow><mi>max</mi></mrow></msub></math></span>) of the azimuthal instability decreases while the corresponding wavelength increases with the divergence angle of the magnetic field, defined as tan<sup>−1</sup>(<span><math><mrow><msub><mrow><mi>B</mi></mrow><mrow><mi>x</mi></mrow></msub><mo>/</mo><msub><mrow><mi>B</mi></mrow><mrow><mi>z</mi></mrow></msub></mrow></math></span>). As for the electric field effects, <span><math><msub><mrow><mi>γ</mi></mrow><mrow><mi>max</mi></mrow></msub></math></span> increases with a stronger parallel electric field <span><math><msub><mrow><mi>E</mi></mrow><mrow><mo>∥</mo></mrow></msub></math></span> along the magnetic field lines, whereas the corresponding wavelength becomes shorter. In contrast, the perpendicular electric field <span><math><msub><mrow><mi>E</mi></mrow><mrow><mo>⊥</mo></mrow></msub></math></span> shows negligible influence on the instability. These findings suggest that maintaining the magnetic field divergence angle between 30°and 45°, along with reducing the magnetic field gradient, can effectively suppress azimuthal instabilities in ECR magnetic nozzles.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"242 ","pages":"Article 114717"},"PeriodicalIF":3.9,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145106397","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

Numerical study of RF DBD in atmospheric argon: Effect induced by dielectric thickness on symmetry and characteristics of discharges 大气氩气中射频DBD的数值研究：介质厚度对放电对称性和特性的影响

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-09-11 DOI: 10.1016/j.vacuum.2025.114726

Ze-Hui Zhang , Ke-Xin Zhong , Na Gao , Yue Liu , Wei Wang , Yi-Nan Wang , De-Zheng Yang

{"title":"Numerical study of RF DBD in atmospheric argon: Effect induced by dielectric thickness on symmetry and characteristics of discharges","authors":"Ze-Hui Zhang , Ke-Xin Zhong , Na Gao , Yue Liu , Wei Wang , Yi-Nan Wang , De-Zheng Yang","doi":"10.1016/j.vacuum.2025.114726","DOIUrl":"10.1016/j.vacuum.2025.114726","url":null,"abstract":"<div><div>We develop a self-consistent one-dimensional model based on plasma fluid theory and the drift-diffusion approximation to investigate how the discharge characteristics, as well as the symmetry, in atmospheric argon RF DBD, are affected when there are differences in the dielectric thickness. The simulation results show that as the dielectric thickness increases, the produced plasma density decreases. The thicker dielectric hinders the ionization process, leading to a significant decrease in the overall ionization rate and electron power absorption of the discharge and a change in their distribution, which characterizes the transition of the discharge from the <em>α-γ</em> mode to the <em>α</em>-mode. Moreover, the asymmetric dielectric thickness allows the variation of the electric field to accrue to the thinner side of the dielectric thickness, which in turn deflects the distribution of the plasma towards this side. Also, it behaves as an <em>α-γ</em> mode on the thinner side of the dielectric and an <em>α</em>-mode on the other side, resulting in different discharge modes occurring simultaneously on both sides of the same discharge gap. The asymmetric effect of the dielectric thickness on the energy produced is more evident in electron pressure heating and less in electron Ohmic heating.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"242 ","pages":"Article 114726"},"PeriodicalIF":3.9,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145046014","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

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