VacuumPub Date : 2025-10-01DOI: 10.1016/j.vacuum.2025.114789
Yonghong Cao , Zhenghao Ren , Liwei Zheng , Ganggang Wang , Hao Lin , Zhenlin Yang , Fengchun Jiang , Shusheng Xu
{"title":"Effect of pressure driven energy transfer on the microstructure and tribological properties of CrN coatings: A multi-scale modeling and experimental study","authors":"Yonghong Cao , Zhenghao Ren , Liwei Zheng , Ganggang Wang , Hao Lin , Zhenlin Yang , Fengchun Jiang , Shusheng Xu","doi":"10.1016/j.vacuum.2025.114789","DOIUrl":"10.1016/j.vacuum.2025.114789","url":null,"abstract":"<div><div>A comprehensive multi-scale simulation and experimental study was conducted to elucidate the influence of sputtering pressure on the growth mechanism and performance of CrN coatings deposited by magnetron sputtering. Experimental characterizations revealed that higher sputtering pressures lead to reduced grain density, increased surface roughness, a preferred orientation shift from (200) to (111), and degraded mechanical and tribological properties. The multi-scale simulation framework was used to simulate energy transfer from plasma to atomic deposition and to quantify the energy per arriving atom (EPA) by integrating plasma discharge, sputtering and transport of target atoms, and atomic deposition. Simulations demonstrated that under high pressure the reduced EPA induced by the increased collision effect suppresses adatom mobility, resulting in the island-like growth mode and coarse microstructures. Under low pressure, higher energy transfer facilitates densification and (200)-oriented growth through layer-by-layer growth mode. It was further revealed that ion bombardment plays a critical role in coating densification under low pressure, while the degradation in coating quality was primarily attributed to the decreased energy contribution from energetic neutrals under high pressure. This study provides atomistic insight into the pressure-driven microstructure evolution and offers predictive guidance for optimizing process parameters in plasma-assisted deposition technologies.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"243 ","pages":"Article 114789"},"PeriodicalIF":3.9,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145270012","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}
VacuumPub Date : 2025-09-30DOI: 10.1016/j.vacuum.2025.114785
Hsuan-Ling Kao , Li-Chun Chang , Min-Hsuan Lu , Chun-Bing Chen , Wen-Hung Chung , Chia-Hsuan Tsai , Hsien-Chin Chiu
{"title":"Inkjet printing of silver film on polydimethylsiloxane for soft electronics","authors":"Hsuan-Ling Kao , Li-Chun Chang , Min-Hsuan Lu , Chun-Bing Chen , Wen-Hung Chung , Chia-Hsuan Tsai , Hsien-Chin Chiu","doi":"10.1016/j.vacuum.2025.114785","DOIUrl":"10.1016/j.vacuum.2025.114785","url":null,"abstract":"<div><div>This study reports an optimized inkjet printing strategy for creating conductive patterns on polydimethylsiloxane (PDMS) substrates, addressing limitations in previous methods such as poor film uniformity, low conductivity, and limited mechanical resilience. Surface modification using dielectric barrier discharge plasma at 30 W for 1 s achieved a uniform water contact angle of 50°, enhancing surface uniformity without damaging the substrate. Optimized printing parameters—including droplet spacing (23 μm), jetting voltage (27 V), substrate temperature (60 °C), and multilayer deposition—resulted in silver films with a thickness of 3.1 μm and conductivity of 2.89 × 10<sup>6</sup> S/m. High-frequency performance was validated using a printed transmission line with a 200 μm line width, showing an insertion loss of −0.98 ± 0.03 dB at 9.5 GHz. Mechanical durability was confirmed through 5000 bending cycles, with only a 1.13-fold increase in sheet resistance. Compared to previous PDMS-based inkjet systems, this method offers improved electrical, RF, and mechanical stability. While the process uses commercially available materials and low-energy steps for cost-effectiveness, challenges remain in scalability and environmental sensitivity. These results demonstrate a significant advancement in printed electronics on flexible substrates, supporting future integration into wearable, biomedical, and high-frequency applications.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"243 ","pages":"Article 114785"},"PeriodicalIF":3.9,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145270006","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}
{"title":"Structure-enhanced ultra-high EMI shielding in corrugated recycled carbon fiber felts","authors":"Daxing Cai, Yue Feng, Jiajun He, Xiaoying Wang, Wei Yu, Qiaole Hu, Zhenzhen Xu","doi":"10.1016/j.vacuum.2025.114790","DOIUrl":"10.1016/j.vacuum.2025.114790","url":null,"abstract":"<div><div>The rapid advancement of electronic information technology has led to a significant increase in electromagnetic radiation from electronic devices, posing potential threats to human health. Developing lightweight, high-performance, and green electromagnetic interference (EMI) shielding materials is crucial for mitigating electromagnetic pollution. Herein, uniformly dispersed recycled carbon fiber corrugated felt (rCCFF) was fabricated via wet-laid technology combined with structural design. Results demonstrate that the corrugated structure significantly enhances the shielding effectiveness (EMI SE). Optimal EMI SE of 46 dB was achieved when the corrugation direction was parallel (0°) to the polarization direction of the electromagnetic field, representing a 29.6 % improvement over the planar structure. Reducing the corrugation diameter to 1.2 mm enhanced multiple reflections and interfacial polarization, further increasing the EMI SE to 55.26 dB. Moreover, the double-layer stacked structure forms numerous miniature air cavities, effectively exciting multiple reflections and creating multi-scale resonant coupling, thereby achieving an excellent EMI SE of up to 68.5 dB.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"243 ","pages":"Article 114790"},"PeriodicalIF":3.9,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145223115","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}
{"title":"Influence of substrate temperature on the structural, morphological, and piezocatalytic performance of Ba2TiO4 films deposited by magnetron sputtering","authors":"J.R. Li, C.Y. Ma, J.F. Gao, H.S. Liu, Y.R. Wang, X.Q. Jin, N. Zhou, Q.Y. Zhang","doi":"10.1016/j.vacuum.2025.114787","DOIUrl":"10.1016/j.vacuum.2025.114787","url":null,"abstract":"<div><div>Thin films of Ba<sub>x</sub>TiO<sub>4</sub> (1.59 ≤ x ≤ 1.83) were fabricated via magnetron sputtering, and the influence of substrate temperature (<em>T</em><sub>s</sub>: 400–800 °C) on their structural, compositional, optical, and piezocatalytic properties was systematically investigated by various techniques including XRD, XPS, AFM, EDS, SEM, UV–vis DRS and PL. XRD analysis confirmed that films grown at 400 °C exhibit an amorphous phase, whereas well-crystallized Ba<sub>2</sub>TiO<sub>4</sub> films with a monoclinic β phase are obtained at <em>T</em><sub>s</sub> above 550 °C. As <em>T</em><sub>s</sub> rises from 400 °C to 800 °C, there is a decrease in <em>E</em><sub>g</sub> from 3.84 eV to 3.58 eV. The piezocatalytic performance of the films was evaluated using methylene blue (MB) dye degradation as an indicator. The rate constant <em>k</em> is estimated to be in the range of 0.060–0.045 min<sup>−1</sup> for well-crystallized films grown at <em>T</em><sub>s</sub> values ranging from 700 to 800 °C, which is 5 to 3.75 times higher than that of amorphous films grown at 400 °C (k∼0.012 min<sup>−1</sup>). The results show that by altering the substrate temperature during reactive sputtering, it is feasible to grow Ba<sub>2</sub>TiO<sub>4</sub> thin films with some advantageous properties such as a higher Ba/Ti ratio, good crystallinity, low defect states and narrowed band gap, offering promising applications for piezocatalyzed degradation of organic pollutants in wastewater treatment.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"243 ","pages":"Article 114787"},"PeriodicalIF":3.9,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145270010","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}
VacuumPub Date : 2025-09-30DOI: 10.1016/j.vacuum.2025.114788
Haitao Xu , Junyi Pan , Jiao Shi , Duo Dong , Dongdong Zhu , Yongde Huang , Liu Zhu , Chuanyang Lu , Yanming He
{"title":"Relieving the residual stresses in diamond/copper combination using the Y2W3O12 NTE particles doped Ag-based filler alloys","authors":"Haitao Xu , Junyi Pan , Jiao Shi , Duo Dong , Dongdong Zhu , Yongde Huang , Liu Zhu , Chuanyang Lu , Yanming He","doi":"10.1016/j.vacuum.2025.114788","DOIUrl":"10.1016/j.vacuum.2025.114788","url":null,"abstract":"<div><div>Fabrication of the diamond microwave windows faced challenges due to the pernicious residual stresses within the diamond/copper brazing joint. In this work, the Y<sub>2</sub>W<sub>3</sub>O<sub>12</sub> (YWO) with negative coefficient of thermal expansion were introduced into AgCuSnTi filler to mitigate the residual stresses of the diamond/copper joint. The effect of the YWO content on the microstructure, shear strength, and the residual stresses of the joints were investigated. Furthermore, the joint formation mechanism and the reliving mechanism of the residual stresses was unveiled. The microstructure of the joints brazed with AgCuSnTi+1 vol% was mainly composed of Ag(s,s), Cu(s,s), CuSn<sub>3</sub>Ti<sub>5</sub>, CuTi, and YWO particles. The TiO<sub>2</sub>+Ti<sub>4</sub>Cu<sub>2</sub>O double layers formed surrounding the YWO particles facilitated the bonding between the metallic filler and non-metallic YWO particles. The residual stresses detected are relieved by 15.8 %, and the corresponding shear strength of the joints reached 253.7 MPa. When increasing the content of YWO (3 and 5 vol%), the number of the CuSn<sub>3</sub>Ti<sub>5</sub>, and CuTi was reduced, however, the YWO aggregation defects formed wreaked the bonding strength of the joints severely. To conclude, a small amount of YWO addition could relive the residual stresses within the diamond/copper joints and provide guidance for fabrication of the diamond microwave windows.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"243 ","pages":"Article 114788"},"PeriodicalIF":3.9,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145223542","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}
VacuumPub Date : 2025-09-29DOI: 10.1016/j.vacuum.2025.114784
Philipp Alizadeh, Rainer Dahlmann
{"title":"Evaluation of a novel PECVD reactor for the intended continuous coating of flexible web material","authors":"Philipp Alizadeh, Rainer Dahlmann","doi":"10.1016/j.vacuum.2025.114784","DOIUrl":"10.1016/j.vacuum.2025.114784","url":null,"abstract":"<div><div>PET film samples were coated on a novel Plasma-Enhanced Chemical Vapor Deposition (PECVD) reactor. The reactor represents a pioneering development as the first of its kind to be designed for the continuous coating of plastic film. The reactor is equipped with sequentially arranged airlocks, that facilitate a gradual reduction in pressure from ambient pressure to process pressure levels of a few pascals. The airlocks are equipped with slits that facilitate the uninterrupted introduction and extraction of the web material. In the experiments presented however, the film was positioned manually in the reactor to eliminate any potential influence from sliding contacts or similar mechanical stresses associated with film transport. The leakage flows associated with the airlocks were present in a manner consistent with subsequent automated operation. An investigation of the leakages was published earlier.</div><div>In the study presented here, the utilization of OTR measurements was instrumental in demonstrating the potential to align the coating process with the airlock system. Depending on the position inside the coating area, barrier against oxygen was improved by factors of up to 29. Furthermore, coating thickness measurements were utilized to show that the coating of the reactor walls was significantly reduced by using a process envelope.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"243 ","pages":"Article 114784"},"PeriodicalIF":3.9,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145270002","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}
{"title":"Design of pulsed DC magnetron sputtering power supply with adjustable igniting voltage","authors":"Wenguang Chen, Xiaofeng Wang, Ke Tan, Tianyi Duan, Ruixuan Zhou, Pengcheng Zhang","doi":"10.1016/j.vacuum.2025.114778","DOIUrl":"10.1016/j.vacuum.2025.114778","url":null,"abstract":"<div><div>Plasma sputtering technology is widely used in high-end manufacturing industries, such as material surface treatment. Pulsed DC plasma sputtering technology is preferred over continuous DC power supplies due to its greater process control flexibility and improved energy utilization efficiency. The sputtering power supply operates in a pulse mode, where the main challenge to ensure rapid ignition of each pulse and maintain a constant root-mean-square (RMS) pulse current. This paper proposes a novel pulsed DC sputtering power supply topology. By utilizing the dead time of the full bridge converter and the control sequence of the pulse generator, a pulsed output is achieved. This approach significantly reduces the current and voltage stress limit on the switching devices within the pulse generator. Furthermore, the pulse generation circuit is designed to achieve fast and stable pulse current, with an adjustable and controllable ignition voltage at the leading edge of the pulse. A 20 kW prototype was developed to validate the design. The output repetition frequency reaches up to 100 kHz, the duty cycle is adjustable between 10 % and 100 %, and the maximum ignition voltage reaches 2 kV, making it suitable for a wide range of sputtering load requirements.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"243 ","pages":"Article 114778"},"PeriodicalIF":3.9,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145183783","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}
VacuumPub Date : 2025-09-28DOI: 10.1016/j.vacuum.2025.114783
Shi Li , Xian-wen Ran , Wei-feng Cui , Duo Zhang , Wen-hui Tang
{"title":"Flow field of sonic underexpansion transient jet: Research on the characteristics of transient jet velocity and vortex ring translate velocity","authors":"Shi Li , Xian-wen Ran , Wei-feng Cui , Duo Zhang , Wen-hui Tang","doi":"10.1016/j.vacuum.2025.114783","DOIUrl":"10.1016/j.vacuum.2025.114783","url":null,"abstract":"<div><div>This research aims to further investigate the motion law of the sonic underexpansion transient jet and vortex ring. The functional relationship between the dimensionless peak velocity (<em>U∗</em>) of the jet at the center of the nozzle and the incident shock wave Mach number (<em>Ms</em>) is constructed. The vortex ring translate velocity (<em>U</em>) equation is also optimized. Three <em>Ms</em> including <em>Ms</em> = 1.414, 1.479, 1.547 are set to generate sonic underexpansion transient jet and vortex ring, and the corresponding simulations and experiments are carried out. The results show that the theoretical calculations of <em>U∗</em> and <em>U</em> are in good agreement with the simulations. The increase in <em>Ms</em> results in an increase in the diameter, circulation, vortex ring translate velocity and transient jet velocity (<em>u</em>). The vortex ring motion process is divided into growth, pinch-off, and decay stages. In the growth stage, the vortex ring circulation grows rapidly, but its growth rate gradually decreases. The vortex ring exhibits a higher circulation growth rate at higher <em>Ms</em>. At the decay stage, the decay rate of vortex ring circulation is very slow compared to the growth rate during the growth stage. This indicates that the vortex ring has a strong anti-decay ability.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"243 ","pages":"Article 114783"},"PeriodicalIF":3.9,"publicationDate":"2025-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145223113","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}
VacuumPub Date : 2025-09-28DOI: 10.1016/j.vacuum.2025.114782
A.O. Amisi, R. Garza-Hernández, F. Ambriz-Vargas
{"title":"Deposition pressure-driven evolution of composition, structure, optical, and electrochemical properties in LiNixMnyCozO2 thin films","authors":"A.O. Amisi, R. Garza-Hernández, F. Ambriz-Vargas","doi":"10.1016/j.vacuum.2025.114782","DOIUrl":"10.1016/j.vacuum.2025.114782","url":null,"abstract":"<div><div>The development of high-performance LiNi<sub>x</sub>Mn<sub>y</sub>Co<sub>z</sub>O<sub>2</sub> (NMC) thin-film cathodes for advanced lithium-ion micro-batteries requires precise control over deposition conditions to optimize structural and electrochemical properties. This study investigates the influence of Ar working pressure (4, 8, 12, 16, and 20 mTorr) during RF magnetron sputtering on the physicochemical characteristics of NMC thin-film, focusing on potential effects from residual gas contamination. Structural analysis reveals that intermediate pressures (8 mTorr) enhance crystallinity, reduce lattice spacing (4.68 Å), and induce compressive stress (−0.811 GPa). SEM demonstrated pressure-dependent morphological evolution, with higher pressures (20 mTorr) yielding thinner films (66.6 nm) and finer grains (21.4 nm) due to reduced adatom mobility. XPS highlighted elemental modulation, showing lithium depletion (32.57–18.04 %) at elevated pressures, alongside increased Mn<sup>2+</sup>/Mn<sup>3+</sup> and Co<sup>2+</sup>/Co<sup>3+</sup> oxidation states, indicative of oxygen vacancy generation. Optical bandgap narrowing (3.22–2.91 eV) with pressure highlights defect-induced electronic modifications. Electrochemical testing of the 8 mTorr film reveals an initial discharge capacity of 65.21 mAh/g, but with rapid capacity fade (9.29 % retention after 60 cycles), accompanied by charge transfer resistance (R<sub>ct</sub> = 779.30 Ω) and microstructural degradation. These findings serve as proof-of-concept data, highlighting the influence of sputtering pressure on film properties and guiding future optimization for integrated microbattery development.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"242 ","pages":"Article 114782"},"PeriodicalIF":3.9,"publicationDate":"2025-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145220699","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}
VacuumPub Date : 2025-09-27DOI: 10.1016/j.vacuum.2025.114769
Nikita Pavlushin, Jie Wang, Fangyu Liu, Muchen Zhou
{"title":"Pressure prediction under the condition of vacuum gauge failure in ultra high vacuum systems using regression model","authors":"Nikita Pavlushin, Jie Wang, Fangyu Liu, Muchen Zhou","doi":"10.1016/j.vacuum.2025.114769","DOIUrl":"10.1016/j.vacuum.2025.114769","url":null,"abstract":"<div><div>Particle accelerators are complex and large facilities requiring appropriate maintenance and operation condition control. Despite accelerator facility staff following all necessary operation regulations and the high-quality equipment usage, it is impossible to avoid some minor faults causing the pressure to arise inside the facility vacuum vessel. However, it is possible that during particle accelerator operation there is a gauge fault but vacuum pipeline pressure does not exceed the estimated critical value. In this case, operation should not be stopped, and the gauge can be easily replaced at the next planned maintenance session. In this article, the combination of Monte Carlo pressure simulation and a linear regression model to predict the pressure profile along the pipeline axis is shown. As a result, a trained AI-model based on a linear regression algorithm is able to predict the maximal pressure in the vacuum pipeline and define the pressure on a broken gauge according to other gauges’ measurements.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"242 ","pages":"Article 114769"},"PeriodicalIF":3.9,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145220701","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}