VacuumPub Date : 2025-04-29DOI: 10.1016/j.vacuum.2025.114350
Sandeep Kumar Maurya , Eun Ji Yang , Sang Yeol Lee
{"title":"High-performance full-swing a-HfInZnO inverter and advanced integrated logic circuits","authors":"Sandeep Kumar Maurya , Eun Ji Yang , Sang Yeol Lee","doi":"10.1016/j.vacuum.2025.114350","DOIUrl":"10.1016/j.vacuum.2025.114350","url":null,"abstract":"<div><div>We report the fabrication and characterization of high-performance, full-swing inverter and logic circuits based on amorphous hafnium-indium-zinc-oxide (a-HIZO) thin film transistors (TFTs) with varying channel layer thicknesses. Structural and compositional analyses were performed to validate the amorphous nature and chemical uniformity of the HIZO matrix. High-resolution transmission electron microscopy (HRTEM) confirmed the absence of crystallinity. Energy-dispersive X-ray spectroscopy (STEM-EDX) elemental mapping revealed homogeneous distribution of Hf, In, Zn, and O, supporting the multicomponent oxide system. X-ray photoelectron spectroscopy (XPS) analysis was conducted to investigate the elemental composition and oxidation states of Hf, In, Zn, and O. The transmission line method (TLM) was utilized to ensure ohmic contact between the electrodes and the channel layer, and to calculate total resistance, sheet resistance, and contact resistance. The TFTs demonstrated excellent electrical performance, including a maximum field-effect mobility of 13.5 <span><math><mrow><msup><mrow><mi>cm</mi></mrow><mrow><mn>2</mn></mrow></msup><mspace></mspace><msup><mrow><mi>V</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup><mspace></mspace><msup><mrow><mi>s</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math></span>, an on/off current ratio of 10<span><math><msup><mrow></mrow><mrow><mn>8</mn></mrow></msup></math></span>, and stable operation under temperature stress. The a-HIZO-based inverters achieved a maximum voltage gain of 32.38 at a supply voltage of 16 V. In addition, logic circuits, such as NOR and NAND gates, were fabricated, showcasing sharp transfer characteristics. These results highlight the potential of a-HIZO TFTs for advanced electronic applications.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"239 ","pages":"Article 114350"},"PeriodicalIF":3.8,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143887054","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 : 2025-04-28DOI: 10.1016/j.vacuum.2025.114376
Kaidi Hu , Xiantao Yan , Degao Qiao , Xin Du , Guotang Zhang , Xiaolong Zhao , Jian Li , Yuanli Xu , Peng Peng
{"title":"Spangle formation on surface of Galvalume steel sheets: Study of microstructure control through cooling dynamics and titanium addition","authors":"Kaidi Hu , Xiantao Yan , Degao Qiao , Xin Du , Guotang Zhang , Xiaolong Zhao , Jian Li , Yuanli Xu , Peng Peng","doi":"10.1016/j.vacuum.2025.114376","DOIUrl":"10.1016/j.vacuum.2025.114376","url":null,"abstract":"<div><div>The spangle formation of Galvalume steel sheets under different cooling rates (5 °C/s and 15 °C/s) and titanium additions (0.1–0.5 wt%) are investigated. The SEM results show that the increased cooling rate can lead to the increase of the number of surface spangles and decrease of the spangle size. The XRD results show that the TiAl<sub>3</sub> phases are located in the center of the spangle on surface of Galvalume steel sheet, indicating that the TiAl<sub>3</sub> phases can act as a heterogeneous nucleus. The TEM analysis of spangle center is presented with Ti additions, The planar disregistries of TiAl<sub>3</sub> phase and Al-rich phase are calculated. The planar disregistries are considered to be small enough in terms of lattice coherency except (100)TiAl<sub>3</sub>//(001)Al. It is possible for Al-rich phase growth from TiAl<sub>3</sub> nuclei. Since the TiAl<sub>3</sub> phase acts as heterogeneous nucleation sites, increasing the density of nucleation sizes, the spangles size decreases. With 0.5 wt% Ti additions under 15 °C/s, the spangles reach their minimum size. Besides, the oxygen and hydrogen content of Galvalume are explored and calculated. The EBSD results show that the Al-rich phase texture changes from <320> without Ti addition to <111> with 0.5 wt% Ti additions.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"239 ","pages":"Article 114376"},"PeriodicalIF":3.8,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143895636","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 : 2025-04-28DOI: 10.1016/j.vacuum.2025.114375
Guohui Dou , Jiantao Liu , Qiang Zhang , Tianhao Zhang , Hao Wang
{"title":"Effect of preheating treatment on FGH4108 superalloy powder","authors":"Guohui Dou , Jiantao Liu , Qiang Zhang , Tianhao Zhang , Hao Wang","doi":"10.1016/j.vacuum.2025.114375","DOIUrl":"10.1016/j.vacuum.2025.114375","url":null,"abstract":"<div><div>FGH4108 is a newly designed fourth generation powder metallurgy superalloy. In this paper, the microstructure, precipitate and element distribution of FGH4108 powder prepared by argon atomization after preheating treatment at different temperatures were characterized and analyzed. The effect of preheating temperature on the carbide evolution and surface state of FGH4108 powder was systematically studied. The results show that the carbide forming elements (Ta, Nb, Ti, Hf, Cr, W, Mo) and C of the powder are enriched towards the interior during preheating treatment. As preheating temperature increases, the degree of elemental enrichment increases, the oxidation degree of the powder surface and the oxygen content in the precipitated phase increase. The metastable MC' carbides in the powder transform into stable MC carbides, and the contents of Ta, Nb, Ti and Hf in the carbides increase with the increase of preheating temperature. At the same time, M<sub>23</sub>C<sub>6</sub> and M<sub>6</sub>C carbides are formed. When preheating temperature is less than 1050 °C, the two coexist, and M<sub>23</sub>C<sub>6</sub> carbides are not observed after 1100 °C. In addition, γ′ phase is also precipitated in the powder. As preheating temperature increases, the morphology changes from round to square and the size increases. The increase of preheating temperature promotes the homogenization of the powder microstructure, and precipitates changes from continuous intergranular distribution to dispersed distribution. More C elements are fixed in carbides by strong carbide forming elements. This improves the stability and distribution of carbides in the powder, which is beneficial to reduce the continuous precipitation of carbides on the surface of the powder during hot isostatic pressing.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"239 ","pages":"Article 114375"},"PeriodicalIF":3.8,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143898559","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 : 2025-04-26DOI: 10.1016/j.vacuum.2025.114372
Gengbiao Chen , Can Mo
{"title":"Design and performance analysis of the vacuum system for ion beam sputtering coating machine","authors":"Gengbiao Chen , Can Mo","doi":"10.1016/j.vacuum.2025.114372","DOIUrl":"10.1016/j.vacuum.2025.114372","url":null,"abstract":"<div><div>A high-performance vacuum system is a critical component of an ion beam sputtering (IBS) coating machine, as a clean, high-vacuum environment is essential for ensuring the quality and uniformity of sputtered coatings. This paper presents the design and performance analysis of a vacuum system tailored for IBS processes. A dual-chamber structure optimized for sputtering operations is proposed, and simulation results confirm stable gas flow and the absence of dead zones during main pump operation. Appropriate pump types are selected, and a vacuum system layout is developed to meet the stringent vacuum requirements of the coating process. To achieve accurate prediction of the system's evacuation time, a segmented pumping speed correction factor is introduced, enabling the construction of a sectional vacuum pumping model. Furthermore, a set of synchronized equipment operation commands is devised to realize efficient and automated vacuum pumping. The experimental results of the automated process closely match the model predictions. Compared to existing machines of the same type, the proposed system achieves ultimate vacuum nearly 2 h faster.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"239 ","pages":"Article 114372"},"PeriodicalIF":3.8,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143891285","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 : 2025-04-26DOI: 10.1016/j.vacuum.2025.114369
Ning Zhang , Xiufang Chen , Zheyang Li , Xuejian Xie , Xianglong Yang , Wancheng Yu , Xiaobo Hu , Guanglei Zhong , Le Yu , Rui Jin , Xiangang Xu
{"title":"Suppressing SiC crystal edge decomposition through pore-type crucible","authors":"Ning Zhang , Xiufang Chen , Zheyang Li , Xuejian Xie , Xianglong Yang , Wancheng Yu , Xiaobo Hu , Guanglei Zhong , Le Yu , Rui Jin , Xiangang Xu","doi":"10.1016/j.vacuum.2025.114369","DOIUrl":"10.1016/j.vacuum.2025.114369","url":null,"abstract":"<div><div>As a wide bandgap semiconductor material, silicon carbide (SiC) has promising prospects for application. However, the current commercial production size is limited to six inches, and the challenge of producing larger single crystals increases exponentially as the size grows. The growth of large single crystals is significantly hindered by deteriorating radial growth conditions. This paper proposed a modified crucible structure to improve crystal edge degradation, thereby facilitating the expansion of the crystal diameter. By observing the crystal and the crystallization at the crystal edge and crucible cover, classical nucleation theory was applied to calculate the nucleation process at three potential nucleation sites during the early growth stage: the seed crystal edge, the graphite paper, and the diversion ring. The results indicated that a higher supersaturation ratio facilitated nucleation at the graphite paper, thereby suggesting a potential mechanism for the formation of crystal edge decomposition. To reduce the supersaturation ratio during the early growth stage, a method involving making holes in the crucible cover was proposed. Comparative schemes were conducted with three openings and six openings. The results showed that the six openings crucible effectively reduces the supersaturation ratio during the early growth stage, resulting in the crystal without edge decomposition. Raman and HRXRD-RC results indicated that the crystal had better crystal structure uniformity and higher crystallinity.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"239 ","pages":"Article 114369"},"PeriodicalIF":3.8,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143887052","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 : 2025-04-24DOI: 10.1016/j.vacuum.2025.114358
Zhe Mao , Huan Wang , Chunxia Zhang , Bin Wang , Longxiang Liu
{"title":"Influence of sulfate-reducing bacteria on the corrosion mechanism of Zn-Al-Al2O3 composite coatings in artificial seawater","authors":"Zhe Mao , Huan Wang , Chunxia Zhang , Bin Wang , Longxiang Liu","doi":"10.1016/j.vacuum.2025.114358","DOIUrl":"10.1016/j.vacuum.2025.114358","url":null,"abstract":"<div><div>The impact of sulfate-reducing bacteria (SRB) on the corrosion behavior and mechanism of Zn-Al-Al<sub>2</sub>O<sub>3</sub> composite coating has been studied in artificial seawater solutions. The Zn-Al-Al<sub>2</sub>O<sub>3</sub> composite coating immersed in sterile artificial seawater solution is also tested for comparison. The Zn-Al-Al<sub>2</sub>O<sub>3</sub> composite coating exhibits excellent corrosion resistance and the Zn phase as sacrificing cathodic is corroded first due to its more negative corrosion potential. Surface oxides including ZnO and Al<sub>2</sub>O<sub>3</sub> play a significant role in initial-stage corrosion protection. The <em>I</em><sub><em>corr</em></sub> value increased from 4.623 μA/cm<sup>2</sup> to 8.428 μA/cm<sup>2</sup>, indicating that the presence of SRB affects corrosion products, corrosion rate and corrosion behavior. The corrosion mechanism of the Zn-Al-Al<sub>2</sub>O<sub>3</sub> composite coating in SRB-containing artificial seawater solution is deduced by a detailed analysis of scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XRD) and electrochemistry.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"239 ","pages":"Article 114358"},"PeriodicalIF":3.8,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143878467","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 : 2025-04-24DOI: 10.1016/j.vacuum.2025.114368
Yu Wu , Ling Dong , Zhengyang Qiao , Hongchuan Jiang , Xiaohui Zhao , Yang Li , Jiawei Tian
{"title":"Lattice structure evolution mechanism of carbon and hydrogen co-doped AlN thin films with temperature","authors":"Yu Wu , Ling Dong , Zhengyang Qiao , Hongchuan Jiang , Xiaohui Zhao , Yang Li , Jiawei Tian","doi":"10.1016/j.vacuum.2025.114368","DOIUrl":"10.1016/j.vacuum.2025.114368","url":null,"abstract":"<div><div>Carbon and hydrogen co-doped AlN thin films (AlN&C-H) are deposited on quartz glass with different N<sub>2</sub>/CH<sub>4</sub> gas flow ratios. The influence of N<sub>2</sub>/CH<sub>4</sub> ratio on the lattice structure of AlN&C-H samples is studied. X-ray diffraction peak of AlN&C-H samples shifts to the left obviously, which illustrates that C and H co-doping lead to lattice expansion of AlN thin films. XPS results indicate the interstitial C-H and the substitutional C-H on the lattice sites of Al. High-resolution TEM images exhibit that carbon and hydrogen co-doping causes mass dislocations. High-temperature annealing is used to repair the defects of AlN&C-H samples. The lattice structure evolution law of AlN&C-H samples with temperature is clarified. X-ray diffraction angle (2<em>θ</em>) is carried out to indicate the lattice structure repair degree. In the temperature range of 700∼1100 °C, the 2<em>θ</em> value increases linearly with temperature. The linear variation relation of 2<em>θ</em> with temperature can be used as a criterion for temperature measurement.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"239 ","pages":"Article 114368"},"PeriodicalIF":3.8,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143878468","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 : 2025-04-23DOI: 10.1016/j.vacuum.2025.114366
Yajing Qiao , Decai Li , Yao Ge , Sijia Liu , Xiancai Li
{"title":"Numerical and experimental investigation of magnetic fluid sealing under high-speed conditions","authors":"Yajing Qiao , Decai Li , Yao Ge , Sijia Liu , Xiancai Li","doi":"10.1016/j.vacuum.2025.114366","DOIUrl":"10.1016/j.vacuum.2025.114366","url":null,"abstract":"<div><div>To address the issue of traditional magnetic fluid sealing failing under high-speed conditions, which makes them unsuitable for vacuum sealing applications, a high-speed-resistant magnetic fluid sealing structure was designed and compared with the conventional magnetic fluid sealing structure. The magnetization and rheological properties of two ester-based magnetic fluids were investigated to assess their suitability for high-speed magnetic fluid sealing. The effects of single and dual magnetic sources, pole teeth position, and rotational shaft speed on the sealing performance were compared, providing valuable insights for the design of high-speed-resistant magnetic fluid sealing. A high-speed-resistant magnetic fluid sealing was designed, manufactured, and tested, demonstrating long-term stable operation under high-speed conditions with a 45 mm diameter rotational shaft at 30,000 rpm (surface linear velocity of 70.65 m/s). The results of this study are of significant importance for the design of magnetic fluid sealing capable of meeting the demands of high-speed operating conditions.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"239 ","pages":"Article 114366"},"PeriodicalIF":3.8,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143887051","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 : 2025-04-23DOI: 10.1016/j.vacuum.2025.114365
Haolan Zhang , Zhongwei Chen , Weijiang Song , Yijun Wu , Bo An
{"title":"Precipitation behavior of the secondary L12-Al3(Sc, Zr) phase in the SLM fabricated Al-4Cu-2Mg-0.3Sc-0.7Zr alloy during aging process","authors":"Haolan Zhang , Zhongwei Chen , Weijiang Song , Yijun Wu , Bo An","doi":"10.1016/j.vacuum.2025.114365","DOIUrl":"10.1016/j.vacuum.2025.114365","url":null,"abstract":"<div><div>The precipitation behavior of the secondary L1<sub>2</sub>-Al<sub>3</sub>(Sc, Zr) precipitates in the selective laser melting (SLM) fabricated Al-4Cu-2Mg-0.3Sc-0.7Zr alloy is investigated. And the distribution of Sc and Zr atoms in the secondary Al<sub>3</sub>(Sc, Zr) precipitates at different aging temperatures was studied by HAADF-STEM. The secondary L1<sub>2</sub>-Al<sub>3</sub>(Sc, Zr) precipitates are predominantly comprise Al and Sc atoms after direct aging at 225 °C for 2.5 h, and this indicating that Sc elements primarily control the nucleation and the growth of the L1<sub>2</sub>-Al<sub>3</sub>(Sc, Zr) phase at 225 °C. The distinct Al<sub>3</sub>Sc-rich core and Al<sub>3</sub>Zr-rich shell structure were observed when the aging temperature increases to 440 °C, and both Sc atoms and Zr atoms actively participate in the nucleation and growth of Al<sub>3</sub>(Sc, Zr) particles at 440 °C. Furthermore, Cu element enriched at the interface between Al<sub>3</sub>(Sc, Zr) precipitate and Al matrix following direct aging treatment at 440 °C for 0.5 h. And during non-isothermal aging process, the oxidation was observed occurs at the grain boundary mainly when the aging temperatures were higher than 440 °C.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"239 ","pages":"Article 114365"},"PeriodicalIF":3.8,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143874022","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":"Simulation of yttria hot cathode and radiative emissivity impact on its performances and the work function measurement","authors":"Audrey Mayrat , Quentin Rafhay , Claire Verrier , Jean-Luc Deschanvres","doi":"10.1016/j.vacuum.2025.114363","DOIUrl":"10.1016/j.vacuum.2025.114363","url":null,"abstract":"<div><div>—Despite the decline in their use after the advent of semiconductor devices, hot cathodes still find applications in specialized detectors and high-power systems. This paper focuses on the simulation of the thermal behavior of an oxide cathode (Y<sub>2</sub>O<sub>3</sub>), considering the variation in emissivity as a function of both material and temperature. Most previous studies on hot cathodes have overlooked the importance of radiative emissivity, a parameter that significantly affects thermal exchange, electronic emission and hence the measurement of the work function with a Richardson plot. Our results emphasize the need for a precise measurement of material emissivity to accurately assess cathode performance and enable fair comparisons between different cathode types.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"239 ","pages":"Article 114363"},"PeriodicalIF":3.8,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143874023","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}