IF 3.9 2区材料科学

Vacuum Pub Date : 2025-09-15 DOI: 10.1016/j.vacuum.2025.114749

Keshav Kumar, Chandana Rath

{"title":"Mn doping induced band gap narrowing and enhanced photocatalytic degradation in GdCoO3 perovskite","authors":"Keshav Kumar, Chandana Rath","doi":"10.1016/j.vacuum.2025.114749","DOIUrl":"10.1016/j.vacuum.2025.114749","url":null,"abstract":"<div><div>In recent times, the demand for sustainable and cost-effective photocatalysts has been increasing day by day due to increasing pollutants in water caused by heavy discharge of organic waste through industries. Perovskite materials have emerged as promising candidates due to their excellent catalytic properties. Here, nanocrystalline GdCo<sub>1-<em>x</em></sub>Mn<sub><em>x</em></sub>O<sub>3</sub> (<em>x</em> = 0.0 to 0.30) perovskite materials are synthesized using sol-gel combustion method. Rietveld refinement of X-ray diffraction patterns demonstrates an increase in lattice volume and distortion of the orthorhombic structure, due to substitution of higher ionic radii Mn<sup>3+</sup> ion. XPS analysis reveals the mixed oxidation states of 3+/4+ of Mn, accompanied with 2+/3+ states of Co and an increase in oxygen vacancies with the incorporation of Mn ions. The decrease in optical band gap from 1.87 to 1.32 eV with increasing <em>x</em> indicates the enhancement in photoinduced charge carriers. High degradation efficiency (∼93 %) of Congo red dye is achieved for <em>x</em> = 0.20 due to a suitable band gap, higher oxygen vacancies and larger surface area. Therefore, GdCo<sub>0.80</sub>Mn<sub>0.20</sub>O<sub>3</sub> may be suitable material for wastewater treatment in the textile industry. Furthermore, pH dependent catalytic behaviour and reaction kinetics are thoroughly discussed in the manuscript.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"242 ","pages":"Article 114749"},"PeriodicalIF":3.9,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145106293","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

Redeposition-free dry etching of copper thin films using organic gas mixtures 使用有机气体混合物的铜薄膜无复位干蚀刻

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-09-15 DOI: 10.1016/j.vacuum.2025.114743

Yoon Jae Cho, Ha Rin Song, Hong Ju Yang, Dae Han Won, Chee Won Chung

引用次数: 0

Optimized oxygen flux in sputtering amorphous Ga2O3 thin films enables high-performance solar-blind UV photodetectors 优化溅射非晶Ga2O3薄膜中的氧通量，实现高性能的太阳盲紫外光电探测器

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-09-15 DOI: 10.1016/j.vacuum.2025.114748

Zihan Zhang , Anzhen Zhang , Qiyi Wan , Rui Qin , Xinyue Zhang , Weiwei Cao , Jiuhong Wang

{"title":"Optimized oxygen flux in sputtering amorphous Ga2O3 thin films enables high-performance solar-blind UV photodetectors","authors":"Zihan Zhang , Anzhen Zhang , Qiyi Wan , Rui Qin , Xinyue Zhang , Weiwei Cao , Jiuhong Wang","doi":"10.1016/j.vacuum.2025.114748","DOIUrl":"10.1016/j.vacuum.2025.114748","url":null,"abstract":"<div><div>This study systematically investigates the effect of oxygen flux on the optical properties of amorphous gallium oxide (a-Ga<sub>2</sub>O<sub>3</sub>) thin films deposited on SiO<sub>2</sub>/Si substrates via RF magnetron sputtering. Through comprehensive material characterization and device performance analysis, we elucidate the correlation between defect evolution (including oxygen vacancies and other intrinsic defects) and the resulting optoelectronic responses. Our findings reveal that oxygen vacancy concentration mainly influences the optical band gap. Although increasing oxygen flux significantly reduces the oxygen vacancy concentration, the overall defect density exhibits a nonlinear trend because additional defect states are concurrently introduced. Consequently, the device performance exhibits a nonlinear dependence on oxygen flux. The detector prepared under moderate oxygen flux conditions exhibits an ultra-high light-dark current ratio of up to 4 × 10<sup>5</sup> and a low dark current at the pA level. Furthermore, these devices demonstrate rapid response kinetics, with a rise time of 28.9 ms and a fall time of 0.9 ms. These changes are attributed to the interplay between defects and material properties. This study provides critical insights into the process development of high-performance a-Ga<sub>2</sub>O<sub>3</sub> solar-blind UV photodetectors.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"242 ","pages":"Article 114748"},"PeriodicalIF":3.9,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145106234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

First-principles investigations of structural, electronic and optical properties of cubic and tetragonal IrO2 立方和四方IrO2结构、电子和光学性质的第一性原理研究

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-09-15 DOI: 10.1016/j.vacuum.2025.114747

Nan Wang , Yonghua Duan , Lin Su , Lishi Ma , Ancang Yang , Linhui Su , Bo Huang , Mengnie Li

{"title":"First-principles investigations of structural, electronic and optical properties of cubic and tetragonal IrO2","authors":"Nan Wang , Yonghua Duan , Lin Su , Lishi Ma , Ancang Yang , Linhui Su , Bo Huang , Mengnie Li","doi":"10.1016/j.vacuum.2025.114747","DOIUrl":"10.1016/j.vacuum.2025.114747","url":null,"abstract":"<div><div>Owing to its unique electronic structure and outstanding catalytic performance, IrO<sub>2</sub> holds great potential for applications in energy conversion and storage technologies. In this work, first-principles calculations were employed to comprehensively investigate the electronic structures, phase stability and optical properties of both cubic and tetragonal IrO<sub>2</sub>, with the aim of uncovering their fundamental physical characteristics. The electronic structure analysis, including band structure, density of states, differential charge density, and Mulliken population, reveals that the O–Ir bonds in both cubic (C) and tetragonal (T) IrO<sub>2</sub> exhibit pronounced covalent characteristics, with stronger bonding observed in the tetragonal phase. Optical properties such as dielectric constant, reflectivity, and absorption coefficient were also analyzed. The dielectric constants <em>ε</em><sub>1</sub> (0) of cubic and tetragonal IrO<sub>2</sub> were found to be 29.500 and 36.212, respectively. Additionally, IrO<sub>2</sub> exhibits significant absorption in the ultraviolet (UR) region, and its absorption coefficient gradually decreases with increasing laser wavelength. These findings underscore the strong potential of IrO<sub>2</sub>, particularly its tetragonal phase-as a material for saturable absorbers in laser devices and as a cocatalyst for UR-driven photocatalysis applications, including water splitting and organic pollutant degradation.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"242 ","pages":"Article 114747"},"PeriodicalIF":3.9,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145105851","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

Radiation tolerance of additively manufactured Ti6Al4V: Swelling resistance versus dislocation-mediated hardening under Au2+ ion irradiation 增材制造Ti6Al4V的辐射耐受性：Au2+离子辐照下的抗溶胀与位错介导硬化

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-09-15 DOI: 10.1016/j.vacuum.2025.114755

Chuan Lv , Luhang Yan , Ping Xu , Linfeng Ye , An Li , Lvjun Zhou

引用次数: 0

Surface characteristics and biological evaluation of TiO2 nanotubes fabricated on Ti6Al4V implant surface Ti6Al4V植入表面制备TiO2纳米管的表面特性及生物学评价

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-09-13 DOI: 10.1016/j.vacuum.2025.114742

Konduru Ashok Kumar Raju, Amit Biswas

{"title":"Surface characteristics and biological evaluation of TiO2 nanotubes fabricated on Ti6Al4V implant surface","authors":"Konduru Ashok Kumar Raju, Amit Biswas","doi":"10.1016/j.vacuum.2025.114742","DOIUrl":"10.1016/j.vacuum.2025.114742","url":null,"abstract":"<div><div>The significant focus of this research was to create the TiO<sub>2</sub> (Titanium dioxide) highly ordered nanotube arrays on a Ti6Al4V surface to improve surface roughness, antibacterial activity and biocompatibility for its use in biomedical applications. In this approach, the anodic oxidation process was carried out in the organic bath solution, which is composed of ethylene glycol, NH<sub>4</sub>F, and ultrapure water. The process was carried out at a constant voltage of 30 V under different anodic oxidation time durations of 3 h, 4 h, and 5 h. The surface roughness of the polished Ti6Al4V, TiO<sub>2</sub> 30 V 3 h, TiO<sub>2</sub> 30 V 4 h, and TiO<sub>2</sub> 30 V 5 h are 2.77 nm, 16.92 nm, 19.75 nm, and 22.01 nm respectively. The early-stage assessment of the antimicrobial efficacy of oxidized specimens was conducted quantitatively against Bacillus subtilis and Escherichia coli after a 24 h period of growth. The cell viability on different surfaces was investigated by MTT and adhesion assays, which revealed improved in vitro response to the crystalline nanotubes. Overall, this work demonstrates the importance of using multifunctional TiO<sub>2</sub> nanotubes to provide a synergistic impact on antibiofilm, antibacterial, and enhanced osseointegration.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"242 ","pages":"Article 114742"},"PeriodicalIF":3.9,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145061059","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

Oscillations of iodine LaB6 hollow cathode 碘LaB6空心阴极的振荡

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-09-13 DOI: 10.1016/j.vacuum.2025.114744

Xin Li , Tianhang Meng , Zhongxi Ning , Hui Liu , Chao Sun , Yang Liu , Stepan I. Eliseev , Daren Yu

{"title":"Oscillations of iodine LaB6 hollow cathode","authors":"Xin Li , Tianhang Meng , Zhongxi Ning , Hui Liu , Chao Sun , Yang Liu , Stepan I. Eliseev , Daren Yu","doi":"10.1016/j.vacuum.2025.114744","DOIUrl":"10.1016/j.vacuum.2025.114744","url":null,"abstract":"<div><div>Iodine-fed electric propulsion systems have achieved significant technological progress in recent years, the operating range of these systems remains fundamentally limited by ampere level iodine compatible hollow cathode technology. Preliminary studies on discharge characteristics have found that LaB<sub>6</sub> hollow cathode is a potential strategy. In this study, a conventional LaB<sub>6</sub> hollow cathode made with iodine-resistant materials was designed and tested in an iodine-compatible vacuum facility. The waveform, bispectral characteristics, and dispersion relation of the iodine hollow cathode were obtained and compared with the estimated collision reaction frequency. We analyzed the potential reaction processes both inside and outside the cathode and assessed how oscillation affects the lifetime of the iodine hollow cathode. The results indicate that the chaotic low-frequency oscillations were the main oscillation mode affecting the performance of the iodine cathode, involving multiple reaction processes that interfere with each other. The oscillation inside the cathode was mainly affected by vibrational excitation and iodine molecular ionization, while the oscillation outside the cathode was affected primarily by processes such as neutral gas flow, excitation, ionization, dissociation, and ion transit-time instability. The overall oscillation of iodine cathode is a non-dominant unstable mode with uniform energy distribution. A single 27-h self-sustaining experiment found that low-frequency oscillation has a significant impact on the emitter and the orifice, thereby reducing the cathode lifetime. The main reaction process inside and outside the iodine cathode and the influence relationship between the reactions were understood by the oscillation characteristics. It provides a theoretical basis to improve the performance of the iodine hollow cathode in the future.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"242 ","pages":"Article 114744"},"PeriodicalIF":3.9,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145057381","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

Effect of Fe content on the microstructure and mechanical properties of Al-Cu-Ni-Ti-Fe alloy fabricated by selective laser melting Fe含量对选择性激光熔化Al-Cu-Ni-Ti-Fe合金组织和力学性能的影响

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-09-13 DOI: 10.1016/j.vacuum.2025.114746

Weidong Huang , Guanyu Chen , Xu Huang , Zhaobao Zeng , Yingjin Du , Shuaishuai Qin

引用次数: 0

Spatial distribution of gas flux in molecular flow regime of linear differential pumping systems 线性差动泵系统分子流态中气体通量的空间分布

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-09-12 DOI: 10.1016/j.vacuum.2025.114740

Ziyang He , Haitao Fan , Hailin Bi , Minggao Xu , Xudi Wang , Jiuzhong Yang

{"title":"Spatial distribution of gas flux in molecular flow regime of linear differential pumping systems","authors":"Ziyang He , Haitao Fan , Hailin Bi , Minggao Xu , Xudi Wang , Jiuzhong Yang","doi":"10.1016/j.vacuum.2025.114740","DOIUrl":"10.1016/j.vacuum.2025.114740","url":null,"abstract":"<div><div>Linear differential systems are utilised in accelerators to meet the internal instrumental operating pressures, as well as to allow the passage of operating media such as light and accelerated particles. The system's compact structure and multi-stage series connection present a challenge in calculating the inner pressure of the chambers on the molecular flow. The article uses analytical derivation and numerical integration with MATLAB to investigate the spatial attenuation of gas particle flux out of cylindrical tubes and the gas throughput in the differential pumping systems. The results demonstrate the validity of the model with the experimental data of Adamson and gas spatial distribution patterns of direct-transit flow and wall-reflected flow out of cylindrical tubes. Furthermore, the gas filter, which serves as an example of a linear differential system, is utilised to demonstrate the contribution of each tube to the throughput to the differential chamber. Moreover, the gas particles that are directly traversed by the foremost differential tube constitute the primary gas source of the terminal differential chamber.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"242 ","pages":"Article 114740"},"PeriodicalIF":3.9,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145105854","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

Nd:YAG/Si crystal integration via room-temperature surface activated bonding 室温表面活化键合制备Nd:YAG/Si晶体

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-09-12 DOI: 10.1016/j.vacuum.2025.114739

Ningkang Deng , Jin Yuan , Yongfeng Qu , Liang Du , Wenbo Hu , Zhaoyang Zhang , Shengli Wu , Kang Wang , Hongxing Wang

引用次数: 0

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