Pub Date : 2025-02-13DOI: 10.1016/j.vacuum.2025.114131
Huan W. Zhu , Jian W. Du , Jie Zhang , Li Chen
In this study, the effect of oxygen content on the structure and properties of (Ti1-xSix)(OyN1-y)z coating is investigated. In (Ti1-xSix)(OyN1-y)z coatings, oxygen substitutes nitrogen atoms in TiSiN, forming a single-phase cubic solid solution structure. A small amount of oxygen addition has slight effect on the compressive stress of the coating from −8.35 ± 0.05 GPa for Ti0.83Si0.17N1.02 to −8.61 ± 0.02 GPa for (Ti0.83Si0.17)(O0.10N0.90)1.28, while further increasing oxygen leads to a drop in the compressive stress to −7.76 ± 0.05 GPa for (Ti0.82Si0.18)(O0.21N0.79)1.44 and −4.55 ± 0.01 GPa for (Ti0.82Si0.18)(O0.52N0.48)1.71. The hardness of Ti0.83Si0.17N1.02, (Ti0.83Si0.17)(O0.10N0.90)1.28, (Ti0.82Si0.18)(O0.21N0.79)1.44 and (Ti0.82Si0.18)(O0.52N0.48)1.71 coatings are 39.5 ± 0.9, 38.1 ± 0.6, 36.9 ± 1.0 and 30.5 ± 0.9 GPa, respectively, which can be maintained up to ∼ 1100 °C due to the suppressed grain growth. However, the addition of oxygen reduces the oxidation resistance of TiSiN coatings.
{"title":"Influence of oxygen addition on the structure, mechanical and thermal properties of TiSiN coating","authors":"Huan W. Zhu , Jian W. Du , Jie Zhang , Li Chen","doi":"10.1016/j.vacuum.2025.114131","DOIUrl":"10.1016/j.vacuum.2025.114131","url":null,"abstract":"<div><div>In this study, the effect of oxygen content on the structure and properties of (Ti<sub>1-x</sub>Si<sub>x</sub>)(O<sub>y</sub>N<sub>1-y</sub>)<sub>z</sub> coating is investigated. In (Ti<sub>1-x</sub>Si<sub>x</sub>)(O<sub>y</sub>N<sub>1-y</sub>)<sub>z</sub> coatings, oxygen substitutes nitrogen atoms in TiSiN, forming a single-phase cubic solid solution structure. A small amount of oxygen addition has slight effect on the compressive stress of the coating from −8.35 ± 0.05 GPa for Ti<sub>0.83</sub>Si<sub>0.17</sub>N<sub>1.02</sub> to −8.61 ± 0.02 GPa for (Ti<sub>0.83</sub>Si<sub>0.17</sub>)(O<sub>0.10</sub>N<sub>0.90</sub>)<sub>1.28</sub>, while further increasing oxygen leads to a drop in the compressive stress to −7.76 ± 0.05 GPa for (Ti<sub>0.82</sub>Si<sub>0.18</sub>)(O<sub>0.21</sub>N<sub>0.79</sub>)<sub>1.44</sub> and −4.55 ± 0.01 GPa for (Ti<sub>0.82</sub>Si<sub>0.18</sub>)(O<sub>0.52</sub>N<sub>0.48</sub>)<sub>1.71</sub>. The hardness of Ti<sub>0.83</sub>Si<sub>0.17</sub>N<sub>1.02</sub>, (Ti<sub>0.83</sub>Si<sub>0.17</sub>)(O<sub>0.10</sub>N<sub>0.90</sub>)<sub>1.28</sub>, (Ti<sub>0.82</sub>Si<sub>0.18</sub>)(O<sub>0.21</sub>N<sub>0.79</sub>)<sub>1.44</sub> and (Ti<sub>0.82</sub>Si<sub>0.18</sub>)(O<sub>0.52</sub>N<sub>0.48</sub>)<sub>1.71</sub> coatings are 39.5 ± 0.9, 38.1 ± 0.6, 36.9 ± 1.0 and 30.5 ± 0.9 GPa, respectively, which can be maintained up to ∼ 1100 °C due to the suppressed grain growth. However, the addition of oxygen reduces the oxidation resistance of TiSiN coatings.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"235 ","pages":"Article 114131"},"PeriodicalIF":3.8,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143422367","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 : 2025-02-12DOI: 10.1016/j.vacuum.2025.114127
Huidong Yu , Guodong Wang , Shouzhi Wang , Lei Liu , Jiaoxian Yu , Qiubo Li , Zhongxin Wang , Zhanguo Qi , Xiangang Xu , Lei Zhang
The yellow luminescence (YL) band is commonly observed in gallium nitride (GaN) crystals grown through various methods, and its presence can have detrimental effects on the electronic and optical properties of devices, leading to device degradation. However, the intensity of YL emission exhibits significant variations among different samples. Therefore, it is crucial to investigate the causes of YL generation and these differences in order to mitigate YL formation. In this paper, we present an analysis of four GaN samples grown by hydride vapor phase epitaxy (HVPE) and Ammonothermal method using photoluminescence (PL) spectroscopy and demonstrate that carbon plays a significant role in enhancing YL emission. Additionally, we explore the differential impact of various YL bands on total emission (YL1>YL3>YL2, they correspond to the YL emissions at 2.17 eV, 2.3 eV, and 2.07eV, respectively.). By comparing the relative content levels of different non-radiative point defects, we propose that impurity content variation (particularly elemental carbon) greatly influences YL emission behavior. This provides a novel perspective for understanding the mechanism behind YL formation.
{"title":"The influence of the interaction mechanism between impurities and point defects on the yellow luminescence band of GaN","authors":"Huidong Yu , Guodong Wang , Shouzhi Wang , Lei Liu , Jiaoxian Yu , Qiubo Li , Zhongxin Wang , Zhanguo Qi , Xiangang Xu , Lei Zhang","doi":"10.1016/j.vacuum.2025.114127","DOIUrl":"10.1016/j.vacuum.2025.114127","url":null,"abstract":"<div><div>The yellow luminescence (YL) band is commonly observed in gallium nitride (GaN) crystals grown through various methods, and its presence can have detrimental effects on the electronic and optical properties of devices, leading to device degradation. However, the intensity of YL emission exhibits significant variations among different samples. Therefore, it is crucial to investigate the causes of YL generation and these differences in order to mitigate YL formation. In this paper, we present an analysis of four GaN samples grown by hydride vapor phase epitaxy (HVPE) and Ammonothermal method using photoluminescence (PL) spectroscopy and demonstrate that carbon plays a significant role in enhancing YL emission. Additionally, we explore the differential impact of various YL bands on total emission (YL<sub>1</sub>>YL<sub>3</sub>>YL<sub>2</sub>, they correspond to the YL emissions at 2.17 eV, 2.3 eV, and 2.07eV, respectively.). By comparing the relative content levels of different non-radiative point defects, we propose that impurity content variation (particularly elemental carbon) greatly influences YL emission behavior. This provides a novel perspective for understanding the mechanism behind YL formation.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"234 ","pages":"Article 114127"},"PeriodicalIF":3.8,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143428745","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 : 2025-02-11DOI: 10.1016/j.vacuum.2025.114124
Yachen Xin , Peihua Li , Pengfei Chen , Jian Wang , Xiaohong Li , Wanggang Zhang , Yiming Liu
In this study, a straightforward carbonization technique was utilized to facilitate the in-situ growth of uniformly dispersed carbon nanotubes (CNTs) on porous carbon derived from coal tar pitch. This process yielded a three-dimensional layered composite (ACTP/CNTs) characterized by an exceptionally high specific surface area. The specific surface area of the composite reached 2435.5 m2/g, representing a 42.92 % increase compared to that of the original porous carbon. This three-dimensional structure synergistically combines the excellent lithium-ion storage and transport properties of porous carbon with the excellent electrical conductivity of CNTs. As a result, the ACTP/CNTs demonstrate outstanding electrochemical performance, achieving a high charge capacity of 858.2 mAh/g at 0.2 A/g, and maintaining a stable capacity of 620.1 mAh/g after 1000 cycles at 2 A/g. Full-cell tests further highlight the potential of ACTP/CNTs as promising anode materials for lithium-ion batteries. Our synthetic strategy provides a valuable approach for designing carbon composites and shows great promise for developing high-performance and cost-effective carbon anode materials for lithium-ion batteries.
{"title":"Coal tar pitch-derived porous carbon with in-situ cobalt loading catalyzes the growth of carbon nanotubes as an anode to enhance lithium storage performance","authors":"Yachen Xin , Peihua Li , Pengfei Chen , Jian Wang , Xiaohong Li , Wanggang Zhang , Yiming Liu","doi":"10.1016/j.vacuum.2025.114124","DOIUrl":"10.1016/j.vacuum.2025.114124","url":null,"abstract":"<div><div>In this study, a straightforward carbonization technique was utilized to facilitate the in-situ growth of uniformly dispersed carbon nanotubes (CNTs) on porous carbon derived from coal tar pitch. This process yielded a three-dimensional layered composite (ACTP/CNTs) characterized by an exceptionally high specific surface area. The specific surface area of the composite reached 2435.5 m<sup>2</sup>/g, representing a 42.92 % increase compared to that of the original porous carbon. This three-dimensional structure synergistically combines the excellent lithium-ion storage and transport properties of porous carbon with the excellent electrical conductivity of CNTs. As a result, the ACTP/CNTs demonstrate outstanding electrochemical performance, achieving a high charge capacity of 858.2 mAh/g at 0.2 A/g, and maintaining a stable capacity of 620.1 mAh/g after 1000 cycles at 2 A/g. Full-cell tests further highlight the potential of ACTP/CNTs as promising anode materials for lithium-ion batteries. Our synthetic strategy provides a valuable approach for designing carbon composites and shows great promise for developing high-performance and cost-effective carbon anode materials for lithium-ion batteries.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"234 ","pages":"Article 114124"},"PeriodicalIF":3.8,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143429322","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 : 2025-02-10DOI: 10.1016/j.vacuum.2025.114123
Xiaozheng Su , Yaqi Xu , Haoran Shi , Jianhua Yu , Jing Sui , Qian Zhang , Liyan Yu , Lifeng Dong
Extensive efforts have been made to develop active materials with high energy density to meet the current demand for high-performance energy storage devices. In this study, we successfully achieved a hierarchical structure combining copper oxide and NiCoMn ternary metal hydroxide through a two-step electrochemical deposition process on the surface of a copper wire (CW) current collector. This unique structure consists of an internal honeycomb-like Cu2O framework and external NiCoMn-OH nanosheets. The resulting electrode exhibits enhanced electrochemical performance due to the synergistic effect between these two active materials, demonstrating a high specific capacitance of 956 F g−1 at a current density of 4 A g−1. Moreover, the as-fabricated symmetric flexible supercapacitor exhibited an impressive specific capacitance of 11.06 F cm−3 at a current density of 0.3 A cm−3, along with an excellent capacitance retention rate of up to 93.26 % after 6000 cycles. Moreover, the device demonstrated a remarkable energy density of 0.18 mWh cm−2 when operated at a power density of 11.77 mW cm−2.
{"title":"Hierarchical Cu2O@NiCoMn-OH on copper wire for high-performance flexible supercapacitors","authors":"Xiaozheng Su , Yaqi Xu , Haoran Shi , Jianhua Yu , Jing Sui , Qian Zhang , Liyan Yu , Lifeng Dong","doi":"10.1016/j.vacuum.2025.114123","DOIUrl":"10.1016/j.vacuum.2025.114123","url":null,"abstract":"<div><div>Extensive efforts have been made to develop active materials with high energy density to meet the current demand for high-performance energy storage devices. In this study, we successfully achieved a hierarchical structure combining copper oxide and NiCoMn ternary metal hydroxide through a two-step electrochemical deposition process on the surface of a copper wire (CW) current collector. This unique structure consists of an internal honeycomb-like Cu<sub>2</sub>O framework and external NiCoMn-OH nanosheets. The resulting electrode exhibits enhanced electrochemical performance due to the synergistic effect between these two active materials, demonstrating a high specific capacitance of 956 F g<sup>−1</sup> at a current density of 4 A g<sup>−1</sup>. Moreover, the as-fabricated symmetric flexible supercapacitor exhibited an impressive specific capacitance of 11.06 F cm<sup>−3</sup> at a current density of 0.3 A cm<sup>−3</sup>, along with an excellent capacitance retention rate of up to 93.26 % after 6000 cycles. Moreover, the device demonstrated a remarkable energy density of 0.18 mWh cm<sup>−2</sup> when operated at a power density of 11.77 mW cm<sup>−2</sup>.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"234 ","pages":"Article 114123"},"PeriodicalIF":3.8,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143429323","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 : 2025-02-10DOI: 10.1016/j.vacuum.2025.114122
Sofiya Sharyna , Mikhail Krakov
The paper presents the results of numerical simulation of the problem of diffusion and magnetophoresis rivalry in a magnetic fluid seal (MFS) for vacuum devices. It is taken into account that the diffusion coefficient and viscosity of the fluid (i.e., friction on the surface of the sealed shaft) depend on the concentration of particles. A modified expression for the mobility of particles in a magnetic fluid is used. The result of the rivalry of the studied processes determines the lifespan of the device in the standby mode.
It is revealed that with a sufficiently large magnetic field under the rectangular pole of the MFS, the magnetic fluid loses its fluidity and the device fails. In smaller fields and with large gaps between the pole and the shaft, the maximum concentration and maximum viscosity are not so high, and the seal lifespan in the parking mode is unlimited. The effect of the fluid properties and the design parameters of the MFS pole on the lifespan of the device in large magnetic fields is found. The optimum gap between the pole and the shaft is 0.15–0.2 mm with a pole tip width of 0.3 mm. In the case of a vacuum oil-based magnetic fluid, the seal lifespan in parking mode is about one and a half years.
{"title":"Interplay between magnetophoresis and diffusion in magnetic fluid seals for vacuum devices and their lifespan","authors":"Sofiya Sharyna , Mikhail Krakov","doi":"10.1016/j.vacuum.2025.114122","DOIUrl":"10.1016/j.vacuum.2025.114122","url":null,"abstract":"<div><div>The paper presents the results of numerical simulation of the problem of diffusion and magnetophoresis rivalry in a magnetic fluid seal (MFS) for vacuum devices. It is taken into account that the diffusion coefficient and viscosity of the fluid (i.e., friction on the surface of the sealed shaft) depend on the concentration of particles. A modified expression for the mobility of particles in a magnetic fluid is used. The result of the rivalry of the studied processes determines the lifespan of the device in the standby mode.</div><div>It is revealed that with a sufficiently large magnetic field under the rectangular pole of the MFS, the magnetic fluid loses its fluidity and the device fails. In smaller fields and with large gaps between the pole and the shaft, the maximum concentration and maximum viscosity are not so high, and the seal lifespan in the parking mode is unlimited. The effect of the fluid properties and the design parameters of the MFS pole on the lifespan of the device in large magnetic fields is found. The optimum gap between the pole and the shaft is 0.15–0.2 mm with a pole tip width of 0.3 mm. In the case of a vacuum oil-based magnetic fluid, the seal lifespan in parking mode is about one and a half years.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"234 ","pages":"Article 114122"},"PeriodicalIF":3.8,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143428742","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 : 2025-02-10DOI: 10.1016/j.vacuum.2025.114121
Hanjiang Wu , Tao Huang , Kexing Song , Shaolin Li , Yanjun Zhou , Peng Xu , XiaoWen Peng , Ximeng Luo , YiZhe Xu
To advance the utilization and development of copper-based composite wires, various samples were fabricated, including composite copper wires with Ag-Gr coated, Ag/Gr coated, and drawn Ag/Gr coatings. This study compared and analyzed the morphological characteristics, microstructure, and elemental distribution across different types of composite wires and their interfaces. The findings reveal a robust bonding interface between the composite coating and the copper wire substrate. Notably, interfaces between differing materials varied significantly, categorized either as serrated or flat. A mutual diffusion zone was observed at these interfaces. The coatings contained three primary elements: Cu, Ag, and Gr. Notably, graphene exhibited a higher propensity for diffusion within the silver coating than in the copper wire substrate. In comparison to the pure silver coating, the Ag-Gr mixed coating displayed finer grains, predominantly lath-shaped, with the presence of twinning. Macroscopic examination revealed the surface of the as-plated Ag-Gr coating to be of superior quality. The as-plated Ag/Gr coating exhibited an uneven, close-packed cell structure, which significantly improved in quality after drawing.
{"title":"Study on structural characteristics of composite coating on copper substrate wire surface","authors":"Hanjiang Wu , Tao Huang , Kexing Song , Shaolin Li , Yanjun Zhou , Peng Xu , XiaoWen Peng , Ximeng Luo , YiZhe Xu","doi":"10.1016/j.vacuum.2025.114121","DOIUrl":"10.1016/j.vacuum.2025.114121","url":null,"abstract":"<div><div>To advance the utilization and development of copper-based composite wires, various samples were fabricated, including composite copper wires with Ag-Gr coated, Ag/Gr coated, and drawn Ag/Gr coatings. This study compared and analyzed the morphological characteristics, microstructure, and elemental distribution across different types of composite wires and their interfaces. The findings reveal a robust bonding interface between the composite coating and the copper wire substrate. Notably, interfaces between differing materials varied significantly, categorized either as serrated or flat. A mutual diffusion zone was observed at these interfaces. The coatings contained three primary elements: Cu, Ag, and Gr. Notably, graphene exhibited a higher propensity for diffusion within the silver coating than in the copper wire substrate. In comparison to the pure silver coating, the Ag-Gr mixed coating displayed finer grains, predominantly lath-shaped, with the presence of twinning. Macroscopic examination revealed the surface of the as-plated Ag-Gr coating to be of superior quality. The as-plated Ag/Gr coating exhibited an uneven, close-packed cell structure, which significantly improved in quality after drawing.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"235 ","pages":"Article 114121"},"PeriodicalIF":3.8,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143429800","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 : 2025-02-10DOI: 10.1016/j.vacuum.2025.114120
Chengxiang Wang , Qingsong Li , Yulie Wu , Zhanqiang Hou , Xuezhong Wu , Dingbang Xiao
—This study presents a microelectromechanical system (MEMS) friction gauge for vacuum pressure and gas load measurements of micro chambers. The gauge uses the squeeze film damping to realise high vacuum measurement, and the stability deviation was near 0.608 % over two months. The gauge was integrated into a low temperature co-fired ceramic metal tube (L-Tube in short) and a Kovar tube (K-tube) to measures the vacuum stability and the material outgassing of the laser welding processes. The L-Tube was observed to maintain a vacuum pressure of 1.5 × 10−2 Pa for almost one year (336 days), with a gas load of approximately 1.08 × 10−6 Pa cm3/s under atmospheric pressure. After laser welding, the K-tube with an encapsulated vacuum pressure of 1.45 × 10−2 Pa with a leakage rate of 8.4 × 10−4 Pa cm3/s.
{"title":"MEMS friction vacuum gauge embedded in small vacuum chambers for vacuum and gas load measurement","authors":"Chengxiang Wang , Qingsong Li , Yulie Wu , Zhanqiang Hou , Xuezhong Wu , Dingbang Xiao","doi":"10.1016/j.vacuum.2025.114120","DOIUrl":"10.1016/j.vacuum.2025.114120","url":null,"abstract":"<div><div>—This study presents a microelectromechanical system (MEMS) friction gauge for vacuum pressure and gas load measurements of micro chambers. The gauge uses the squeeze film damping to realise high vacuum measurement, and the stability deviation was near 0.608 % over two months. The gauge was integrated into a low temperature co-fired ceramic metal tube (L-Tube in short) and a Kovar tube (K-tube) to measures the vacuum stability and the material outgassing of the laser welding processes. The L-Tube was observed to maintain a vacuum pressure of 1.5 × 10<sup>−2</sup> Pa for almost one year (336 days), with a gas load of approximately 1.08 × 10<sup>−6</sup> Pa cm<sup>3</sup>/s under atmospheric pressure. After laser welding, the K-tube with an encapsulated vacuum pressure of 1.45 × 10<sup>−2</sup> Pa with a leakage rate of 8.4 × 10<sup>−4</sup> Pa cm<sup>3</sup>/s.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"235 ","pages":"Article 114120"},"PeriodicalIF":3.8,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143422368","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 : 2025-02-10DOI: 10.1016/j.vacuum.2025.114119
Wenpu Li, Wei Yang, Huiyao Men, Shantang Liu
The exposure of triethylamine (TEA) environment can cause a series of damage to the health. Therefore, the high and fast response for TEA detection is significantly required in the industrial and environmental safety. In this paper, a kind of Ag nanoparticles (NPs) decorated metal-organic framework (MOF)-derived ZnO nanoparticles has been described and further explored its TEA-sensing performance. The influence of the Ag-loaded contents over ZnO surface on the structural morphology, crystal size, and dislocation density is investigated in detail. Interestingly, the related sensing tests show the as-prepared gas sensor using 1.3 mol% Ag NPs/ZnO exhibits an outstanding cross-response, high capability (Ra/Rg = 430.6–100 ppm), low detection concentration (1 ppm), along with short response and recovery time (9/49 s), when detecting TEA at the optimal temperature of 225 °C. And this TEA response result is far superior to those of the recent reports. Moreover, the apparent TEA-sensing ability is analyzed from the structural advantage and Ag NPs-introducing effect over this ZnO surface. This article opens a new avenue to design high-responsive sensor based on noble metal-modified MOF-derived oxides.
{"title":"Ag nanoparticle-decorated MOF-derived ZnO nanoparticles for apparent and rapid response towards triethylamine vapor","authors":"Wenpu Li, Wei Yang, Huiyao Men, Shantang Liu","doi":"10.1016/j.vacuum.2025.114119","DOIUrl":"10.1016/j.vacuum.2025.114119","url":null,"abstract":"<div><div>The exposure of triethylamine (TEA) environment can cause a series of damage to the health. Therefore, the high and fast response for TEA detection is significantly required in the industrial and environmental safety. In this paper, a kind of Ag nanoparticles (NPs) decorated metal-organic framework (MOF)-derived ZnO nanoparticles has been described and further explored its TEA-sensing performance. The influence of the Ag-loaded contents over ZnO surface on the structural morphology, crystal size, and dislocation density is investigated in detail. Interestingly, the related sensing tests show the as-prepared gas sensor using 1.3 mol% Ag NPs/ZnO exhibits an outstanding cross-response, high capability (R<sub>a</sub>/R<sub>g</sub> = 430.6–100 ppm), low detection concentration (1 ppm), along with short response and recovery time (9/49 s), when detecting TEA at the optimal temperature of 225 °C. And this TEA response result is far superior to those of the recent reports. Moreover, the apparent TEA-sensing ability is analyzed from the structural advantage and Ag NPs-introducing effect over this ZnO surface. This article opens a new avenue to design high-responsive sensor based on noble metal-modified MOF-derived oxides.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"234 ","pages":"Article 114119"},"PeriodicalIF":3.8,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143394772","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 : 2025-02-08DOI: 10.1016/j.vacuum.2025.114103
H.M. Pereira , B.S. Dores , J.P.O. Silva , A. Venâncio , M.F. Cerqueira , J.A. Rodrigues , J.H. Correia , M.J. Maciel , E.M.F. Vieira
Neuroimaging methods have contributed to enhancing the knowledge of human brain activity. Magnetoencephalography is a general neuroimaging method that typically uses superconducting quantum interference devices as brain magnetic field sensors that require cryogenic cooling, putting practical and economical limitations. Optically pumped magnetometers are a promising alternative based on the use of atomic vapor cells, and eliminate the need for cryogenic conditions. This work focuses on the room-temperature synthesis of a rubidium-85 (85Rb) vapor, using 85Rb azide (85RbN3) and low-temperature anodic bonding for the vapor cell microfabrication. The cell cavities were filled with an Rb azide aqueous solution, which was decomposed under UV light to produce Rb vapor. Spectroscopic characterizations, including Fourier-Transform Infrared Spectroscopy (FTIR) and Raman spectroscopy, were used to analyze the quality of the Rb azide before the UV decomposition. The FTIR results proved the presence of the different functional groups of the Rb azide compound, in solid and aqueous solution. The typical vibrational modes of Rb azide were assigned in Raman spectra. Scanning electron microscopy (SEM) and optical microscopy proved the anodic bonding of silicon and borosilicate, and the presence of Rb vapor after UV decomposition. This work represents an important step towards improving the simplicity of atomic magnetometers fabrication using alkali metals for medical imaging applications.
{"title":"Microfabrication of rubidium-85 vapor cell for optically pumped magnetometer applications through UV light decomposition of rubidium azide","authors":"H.M. Pereira , B.S. Dores , J.P.O. Silva , A. Venâncio , M.F. Cerqueira , J.A. Rodrigues , J.H. Correia , M.J. Maciel , E.M.F. Vieira","doi":"10.1016/j.vacuum.2025.114103","DOIUrl":"10.1016/j.vacuum.2025.114103","url":null,"abstract":"<div><div>Neuroimaging methods have contributed to enhancing the knowledge of human brain activity. Magnetoencephalography is a general neuroimaging method that typically uses superconducting quantum interference devices as brain magnetic field sensors that require cryogenic cooling, putting practical and economical limitations. Optically pumped magnetometers are a promising alternative based on the use of atomic vapor cells, and eliminate the need for cryogenic conditions. This work focuses on the room-temperature synthesis of a rubidium-85 (<sup>85</sup>Rb) vapor, using <sup>85</sup>Rb azide (<sup>85</sup>RbN<sub>3</sub>) and low-temperature anodic bonding for the vapor cell microfabrication. The cell cavities were filled with an Rb azide aqueous solution, which was decomposed under UV light to produce Rb vapor. Spectroscopic characterizations, including Fourier-Transform Infrared Spectroscopy (FTIR) and Raman spectroscopy, were used to analyze the quality of the Rb azide before the UV decomposition. The FTIR results proved the presence of the different functional groups of the Rb azide compound, in solid and aqueous solution. The typical vibrational modes of Rb azide were assigned in Raman spectra. Scanning electron microscopy (SEM) and optical microscopy proved the anodic bonding of silicon and borosilicate, and the presence of Rb vapor after UV decomposition. This work represents an important step towards improving the simplicity of atomic magnetometers fabrication using alkali metals for medical imaging applications.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"234 ","pages":"Article 114103"},"PeriodicalIF":3.8,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143428743","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 : 2025-02-08DOI: 10.1016/j.vacuum.2025.114118
Xiaoyong Song , Yongsheng Xue , Zhenya Cao , Zhizhong Jiang
To improve the irradiation and high thermal load stability of W matrix, tungsten fiber/tungsten-diamond/tungsten (Wf/W-Dia/W) hierarchical composite was prepared by SPS process, and the effects of sintering temperature and holding time on the microstructure, thermal conductivity and thermal shock of Wf/W-Dia/W composites were investigated. The results showed that the relative densities of both Wf/W composites and Dia/W composites were increased with the increase of sintering temperature and holding time. When the sintering temperature and holding time were 1650 °C and 5 min, the higher relative densities were obtained for both composites, which were 98.97 % and 98.58 %, respectively. The recrystallization behavior of W fiber and W matrix was clear with the increase of sintering temperature and holding time. As the sintering temperature and holding time increased, W-C interfacial reaction was more obvious and a more continuous interfacial layer was formed at Dia/W interface, which helped to improve the thermal conductivity of composites, with the highest thermal conductivity of 234 W m−1 K−1. The thermal shock results showed that Wf/W-Dia/W composite with higher relative density and thermal conductivity had better thermal shock resistance. The finite element simulation results revealed that Wf/W-Dia/W composite can effectively alleviate the thermal stress under the cyclic thermal load of 20 MW/m2.
{"title":"Effects of sintering temperature and holding time on the morphologies and properties of Wf/W-Dia/W composite prepared by SPS","authors":"Xiaoyong Song , Yongsheng Xue , Zhenya Cao , Zhizhong Jiang","doi":"10.1016/j.vacuum.2025.114118","DOIUrl":"10.1016/j.vacuum.2025.114118","url":null,"abstract":"<div><div>To improve the irradiation and high thermal load stability of W matrix, tungsten fiber/tungsten-diamond/tungsten (W<sub>f</sub>/W-Dia/W) hierarchical composite was prepared by SPS process, and the effects of sintering temperature and holding time on the microstructure, thermal conductivity and thermal shock of W<sub>f</sub>/W-Dia/W composites were investigated. The results showed that the relative densities of both W<sub>f</sub>/W composites and Dia/W composites were increased with the increase of sintering temperature and holding time. When the sintering temperature and holding time were 1650 °C and 5 min, the higher relative densities were obtained for both composites, which were 98.97 % and 98.58 %, respectively. The recrystallization behavior of W fiber and W matrix was clear with the increase of sintering temperature and holding time. As the sintering temperature and holding time increased, W-C interfacial reaction was more obvious and a more continuous interfacial layer was formed at Dia/W interface, which helped to improve the thermal conductivity of composites, with the highest thermal conductivity of 234 W m<sup>−1</sup> K<sup>−1</sup>. The thermal shock results showed that W<sub>f</sub>/W-Dia/W composite with higher relative density and thermal conductivity had better thermal shock resistance. The finite element simulation results revealed that W<sub>f</sub>/W-Dia/W composite can effectively alleviate the thermal stress under the cyclic thermal load of 20 MW/m<sup>2</sup>.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"234 ","pages":"Article 114118"},"PeriodicalIF":3.8,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143378700","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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