Pub Date : 2026-03-01Epub Date: 2025-12-18DOI: 10.1016/j.vacuum.2025.115019
Xiaoying Yu , Gala Sa , Aiju Xu
The coal chemical industry produces significant wastewater containing refractory organic pollutants, with quinoline being a particularly persistent contaminant in secondary biochemical effluents. To overcome the limitations of standard TiO2 photocatalysts—specifically, their restricted light absorption range and rapid charge recombination—this work created Gd-doped TiO2 (Gd-TiO2) catalysts using a hydrothermal approach. Comprehensive characterization showed that the optimal 1.5 % Gd-TiO2 presents three primary advantages: (1) a 55 % increase in specific surface area (174 m2 g−1), (2) enhanced visible-light absorption through bandgap reduction (3.06 eV), and (3) improved charge separation. These modifications enabled the 1.5 % Gd-TiO2 catalyst to achieve 84 % quinoline degradation within 3 h (mineralization rate: 53.2 %), maintaining 80.3 % efficiency after four cycles, demonstrating exceptional stability. Mechanistic studies revealed a hydroxyl radical-dominated degradation pathway involving sequential benzene-ring opening and pyridine-ring cleavage. This study presents a high-efficiency photocatalyst for industrial wastewater remediation and provides essential insights into rare-earth-modified TiO2 systems.
{"title":"Effective removal of quinoline in wastewater using Gd-TiO2 photocatalyst","authors":"Xiaoying Yu , Gala Sa , Aiju Xu","doi":"10.1016/j.vacuum.2025.115019","DOIUrl":"10.1016/j.vacuum.2025.115019","url":null,"abstract":"<div><div>The coal chemical industry produces significant wastewater containing refractory organic pollutants, with quinoline being a particularly persistent contaminant in secondary biochemical effluents. To overcome the limitations of standard TiO<sub>2</sub> photocatalysts—specifically, their restricted light absorption range and rapid charge recombination—this work created Gd-doped TiO<sub>2</sub> (Gd-TiO<sub>2</sub>) catalysts using a hydrothermal approach. Comprehensive characterization showed that the optimal 1.5 % Gd-TiO<sub>2</sub> presents three primary advantages: (1) a 55 % increase in specific surface area (174 m<sup>2</sup> g<sup>−1</sup>), (2) enhanced visible-light absorption through bandgap reduction (3.06 eV), and (3) improved charge separation. These modifications enabled the 1.5 % Gd-TiO<sub>2</sub> catalyst to achieve 84 % quinoline degradation within 3 h (mineralization rate: 53.2 %), maintaining 80.3 % efficiency after four cycles, demonstrating exceptional stability. Mechanistic studies revealed a hydroxyl radical-dominated degradation pathway involving sequential benzene-ring opening and pyridine-ring cleavage. This study presents a high-efficiency photocatalyst for industrial wastewater remediation and provides essential insights into rare-earth-modified TiO<sub>2</sub> systems.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"246 ","pages":"Article 115019"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145792012","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 : 2026-03-01Epub Date: 2025-12-24DOI: 10.1016/j.vacuum.2025.115049
Qiao Jiang , Yinglin Hu , Xiao Wang , Xiaona Li , Qi Zhu , Yujing Qin , Zhumin Li , Yuehong Zheng , Renwei Liu , Yuanyuan Cui , Chuang Dong , Cuimin Bao , Peter K. Liaw
The multi-component compositional characteristics of high-entropy systems provide the potential to introduce complex inter-component interactions, which can purposefully alter the local structure and generate diverse valence states, paving the way for promising applications in catalysis, energy storage, and sensors. In this paper, the transition metal (TM) element Cu, known for its strong negative enthalpy of mixing with the basic components, and the non-metal element O, which has a large electronegativity difference, are introduced into the TaNbHfZr films. The effects of mixing enthalpy and electronegativity on the local structure are investigated by comparing the microstructure, surface potential, native oxidation, and hardness of the films. The cluster-formula of TaNbHfZr-Cu-O films is further resolved using the cluster-plus-glue-atom model, revealing the mechanism by which the added elements alter the local structure and induce multivalent states. Moreover, the cause of the hardness change is explained by the results of the local structure change, which increases the credibility of the theory. It has been demonstrated that the introduction of Cu under oxygen-free conditions leads to an increase in high-density “clusters with Cu”, causing localized structural fluctuations at the nanoscale. The addition of O serves to attenuate the effect of Cu, thereby homogenizing the potential distribution. Differences in electronegativity between components lead to inhomogeneous filling of O in cluster vacancies, resulting in TM valence states that can fluctuate between +1 and + 4 or +5. The study not only demonstrates the feasibility of introducing multivalent states in the TaNbHfZr system but also theoretically estimates the fluctuation amplitude of oxygen density in the films at the angstrom level, further correlating the fluctuations in valence with those in O density. This provides a theoretical basis for a deeper understanding of the effect of composition on the local structure of high-entropy alloy films and for the purposeful use of multivalent states to enhance properties of material.
{"title":"Cluster-formula interpretation of multivalent state formation in TaNbHfZr-Cu and oxide films","authors":"Qiao Jiang , Yinglin Hu , Xiao Wang , Xiaona Li , Qi Zhu , Yujing Qin , Zhumin Li , Yuehong Zheng , Renwei Liu , Yuanyuan Cui , Chuang Dong , Cuimin Bao , Peter K. Liaw","doi":"10.1016/j.vacuum.2025.115049","DOIUrl":"10.1016/j.vacuum.2025.115049","url":null,"abstract":"<div><div>The multi-component compositional characteristics of high-entropy systems provide the potential to introduce complex inter-component interactions, which can purposefully alter the local structure and generate diverse valence states, paving the way for promising applications in catalysis, energy storage, and sensors. In this paper, the transition metal (TM) element Cu, known for its strong negative enthalpy of mixing with the basic components, and the non-metal element O, which has a large electronegativity difference, are introduced into the TaNbHfZr films. The effects of mixing enthalpy and electronegativity on the local structure are investigated by comparing the microstructure, surface potential, native oxidation, and hardness of the films. The cluster-formula of TaNbHfZr-Cu-O films is further resolved using the cluster-plus-glue-atom model, revealing the mechanism by which the added elements alter the local structure and induce multivalent states. Moreover, the cause of the hardness change is explained by the results of the local structure change, which increases the credibility of the theory. It has been demonstrated that the introduction of Cu under oxygen-free conditions leads to an increase in high-density “clusters with Cu”, causing localized structural fluctuations at the nanoscale. The addition of O serves to attenuate the effect of Cu, thereby homogenizing the potential distribution. Differences in electronegativity between components lead to inhomogeneous filling of O in cluster vacancies, resulting in TM valence states that can fluctuate between +1 and + 4 or +5. The study not only demonstrates the feasibility of introducing multivalent states in the TaNbHfZr system but also theoretically estimates the fluctuation amplitude of oxygen density in the films at the angstrom level, further correlating the fluctuations in valence with those in O density. This provides a theoretical basis for a deeper understanding of the effect of composition on the local structure of high-entropy alloy films and for the purposeful use of multivalent states to enhance properties of material.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"246 ","pages":"Article 115049"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145842103","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 : 2026-03-01Epub Date: 2026-01-13DOI: 10.1016/j.vacuum.2026.115091
Kusuma Putri Suwondo , Muhammad Kozin , Rima Angellina , Yulia Elfena , Diah Ayu Fitriani , Agus Nugroho , Adita Wardani Rahmania , Erie Martides , Muhammad Prisla Kamil , Prabowo Puranto
Hydroxyapatite (HA) coatings enhance the biological integration and corrosion performance of titanium implants; however, conventional direct-current (DC) electrochemical deposition (ECD) often yields porous, weakly adherent layers. This study introduces a DC-biased alternating current (AC) ECD, by superimposing a 10 V sinusoidal waveform onto DC biases of 2.5, 5.0, and 7.5 V, to regulate HA growth on Ti-6Al-4V. Increasing the DC bias shifted the deposition regime, leading to a morphological evolution from short crystallites to elongated, interconnected needle-like networks. X-ray diffraction revealed sharpened HA reflections, indicating enhanced crystallinity, while surface roughness and hydrophilicity also increased. Potentiodynamic polarization demonstrated improved corrosion resistance, with 2.5 VDC exhibit lowest jcorr of (3.17 ± 0.05) × 10−8 A cm−2 and protection efficiencies of (91 ± 4) %. All coatings promoted secondary apatite formation in simulated body fluid. This approach provides a tunable, low-temperature pathway for engineering compact, corrosion-resistant HA layers.
羟基磷灰石（HA）涂层增强了钛种植体的生物整合和腐蚀性能；然而，传统的直流（DC）电化学沉积（ECD）通常会产生多孔的、粘附较弱的层。本研究引入了直流偏置交流（AC） ECD，通过将10 V正弦波形叠加到2.5、5.0和7.5 V直流偏置上，来调节Ti-6Al-4V上HA的生长。增加直流偏压改变了沉积模式，导致从短晶到细长的、相互连接的针状网络的形态演变。x射线衍射显示HA反射增强，表明结晶度增强，表面粗糙度和亲水性也增加。动电位极化具有较好的耐蚀性，在2.5 VDC下，其腐蚀系数最低，为（3.17±0.05）× 10−8 A cm−2，保护效率为（91±4）%。所有涂层都促进了模拟体液中磷灰石的次生形成。这种方法为设计致密、耐腐蚀的HA层提供了可调的低温途径。
{"title":"Dynamic polarity switching under DC-biased AC waveforms: Mechanistic insights into hydroxyapatite coating via electrochemical deposition","authors":"Kusuma Putri Suwondo , Muhammad Kozin , Rima Angellina , Yulia Elfena , Diah Ayu Fitriani , Agus Nugroho , Adita Wardani Rahmania , Erie Martides , Muhammad Prisla Kamil , Prabowo Puranto","doi":"10.1016/j.vacuum.2026.115091","DOIUrl":"10.1016/j.vacuum.2026.115091","url":null,"abstract":"<div><div>Hydroxyapatite (HA) coatings enhance the biological integration and corrosion performance of titanium implants; however, conventional direct-current (DC) electrochemical deposition (ECD) often yields porous, weakly adherent layers. This study introduces a DC-biased alternating current (AC) ECD, by superimposing a 10 V sinusoidal waveform onto DC biases of 2.5, 5.0, and 7.5 V, to regulate HA growth on Ti-6Al-4V. Increasing the DC bias shifted the deposition regime, leading to a morphological evolution from short crystallites to elongated, interconnected needle-like networks. X-ray diffraction revealed sharpened HA reflections, indicating enhanced crystallinity, while surface roughness and hydrophilicity also increased. Potentiodynamic polarization demonstrated improved corrosion resistance, with 2.5 V<sub>DC</sub> exhibit lowest <em>j</em><sub>corr</sub> of (3.17 ± 0.05) × 10<sup>−8</sup> A cm<sup>−2</sup> and protection efficiencies of (91 ± 4) %. All coatings promoted secondary apatite formation in simulated body fluid. This approach provides a tunable, low-temperature pathway for engineering compact, corrosion-resistant HA layers.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"246 ","pages":"Article 115091"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145977649","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}
This study proposes a novel rejuvenation heat treatment (RHT) strategy designed to preserve grain-boundary M23C6 carbides, aiming to regenerate the creep performance of long-term serviced directionally solidified turbine blades. Microstructural characterization reveals section-dependent degradation mechanisms: while the root section mainly exhibits dislocation networks, the airfoil suffers from severe secondary γ′ coarsening, stacking fault shearing, and MC carbide decomposition into brittle η phase. The applied RHT successfully eliminates the deleterious η phase, dissolves coarsened γ′, and refines the strengthening precipitates from 1 μm to 0.35 μm, thereby restoring the alloy's ability to form regular interfacial rafts under stress. Consequently, post-recovery heat treatment yields about 100 % increase in creep life at both blade airfoil and root sections. However, it is found that irreversible Cr-enrichment at airfoil grain boundaries induces spheroidal M23C6 carbides, which accelerates failure. These findings elucidate the microstructural limits of rejuvenation and offer a pathway for optimizing life-extension strategies for critical turbine components.
{"title":"The effect of an innovative rejuvenation heat treatment on the microstructure and creep performance of DS-GTD 111 superalloy","authors":"Lijie Qiao , Yunpeng Fan , Xinbao Zhao , Mingyang Yu , Yu Zhou , Yuan Cheng , Quanzhao Yue , Wanshun Xia , Yuefeng Gu , Ze Zhang","doi":"10.1016/j.vacuum.2025.115056","DOIUrl":"10.1016/j.vacuum.2025.115056","url":null,"abstract":"<div><div>This study proposes a novel rejuvenation heat treatment (RHT) strategy designed to preserve grain-boundary M<sub>23</sub>C<sub>6</sub> carbides, aiming to regenerate the creep performance of long-term serviced directionally solidified turbine blades. Microstructural characterization reveals section-dependent degradation mechanisms: while the root section mainly exhibits dislocation networks, the airfoil suffers from severe secondary γ′ coarsening, stacking fault shearing, and MC carbide decomposition into brittle η phase. The applied RHT successfully eliminates the deleterious η phase, dissolves coarsened γ′, and refines the strengthening precipitates from 1 μm to 0.35 μm, thereby restoring the alloy's ability to form regular interfacial rafts under stress. Consequently, post-recovery heat treatment yields about 100 % increase in creep life at both blade airfoil and root sections. However, it is found that irreversible Cr-enrichment at airfoil grain boundaries induces spheroidal M<sub>23</sub>C<sub>6</sub> carbides, which accelerates failure. These findings elucidate the microstructural limits of rejuvenation and offer a pathway for optimizing life-extension strategies for critical turbine components.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"246 ","pages":"Article 115056"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145977736","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 : 2026-03-01Epub Date: 2026-01-12DOI: 10.1016/j.vacuum.2026.115078
Jayanta Das
Epitaxial NiO films of varying thickness were grown on Ag(001) substrate by molecular beam epitaxy under optimized growth condition and characterized in situ using low-energy electron diffraction (LEED) and photoemission spectroscopy. LEED patterns confirm high crystalline order and reveal coexisting (1 × 2) and (2 × 1) antiferromagnetically reconstructed surface domains in ultrathin films. Angle-resolved ultraviolet photoemission (ARPES) measurements show weakly dispersive Ni -O hybridized bands along - and - directions. Core-level characteristic Ni 2p multiplet features, whose intensity and satellite structure evolve with film thickness and oxygen stoichiometry, were probed by x-ray photoemission. Enhanced nonlocal screening is evident in the ultrathin limit. Comparison of ARPES data with reported theoretical calculations and experimental results facilitates a deeper interpretation of the observed features and validate the reliability and consistency of current findings. Annealing in ultrahigh vacuum creates oxygen vacancies that introduce a non-dispersive defect state near 0.7 eV binding energy (BE). The results establish a comprehensive picture of growth, structure, and electronic evolution in NiO/Ag(001) ultrathin films.
{"title":"Thickness and stoichiometry dependence of the electronic structure of NiO/Ag(001) ultrathin films","authors":"Jayanta Das","doi":"10.1016/j.vacuum.2026.115078","DOIUrl":"10.1016/j.vacuum.2026.115078","url":null,"abstract":"<div><div>Epitaxial NiO films of varying thickness were grown on Ag(001) substrate by molecular beam epitaxy under optimized growth condition and characterized <em>in situ</em> using low-energy electron diffraction (LEED) and photoemission spectroscopy. LEED patterns confirm high crystalline order and reveal coexisting (1 × 2) and (2 × 1) antiferromagnetically reconstructed surface domains in ultrathin films. Angle-resolved ultraviolet photoemission (ARPES) measurements show weakly dispersive Ni <span><math><mrow><mn>3</mn><mi>d</mi></mrow></math></span>-O <span><math><mrow><mn>2</mn><mi>p</mi></mrow></math></span> hybridized bands along <span><math><mover><mrow><mi>Γ</mi></mrow><mo>¯</mo></mover></math></span>-<span><math><mover><mrow><mi>X</mi></mrow><mo>¯</mo></mover></math></span> and <span><math><mover><mrow><mi>Γ</mi></mrow><mo>¯</mo></mover></math></span>-<span><math><mover><mrow><mi>M</mi></mrow><mo>¯</mo></mover></math></span> directions. Core-level characteristic Ni 2p multiplet features, whose intensity and satellite structure evolve with film thickness and oxygen stoichiometry, were probed by x-ray photoemission. Enhanced nonlocal screening is evident in the ultrathin limit. Comparison of ARPES data with reported theoretical calculations and experimental results facilitates a deeper interpretation of the observed features and validate the reliability and consistency of current findings. Annealing in ultrahigh vacuum creates oxygen vacancies that introduce a non-dispersive defect state near 0.7 eV binding energy (BE). The results establish a comprehensive picture of growth, structure, and electronic evolution in NiO/Ag(001) ultrathin films.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"246 ","pages":"Article 115078"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145977733","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 : 2026-03-01Epub Date: 2025-12-12DOI: 10.1016/j.vacuum.2025.114940
Xiang Li , Anmin Li , Shier Wu , Qingping Sui , Zhengliang Wang , Zhuofang Huang , Shiwei Jiang
Through optical microscope, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and tensile testing, The effects of in-situ ZrB2 ceramic particles and rare earth La on the microstructures and mechanical properties of Al-5.4Cu-0.7Mg-0.6Ag alloys have been investigated. Additionally, their synergistic strengthening effect was analyzed. The results show that the Al6Cu6La phase formed after the addition of rare earth La affects the mechanical properties of the composite. With the introduction of La and ZrB2 particles, the average grain size decreases to 28.8 μm, and the strength of the composite improves significantly. When the introduction of ZrB2 reaches 3 wt%, the tensile properties are greatly improved at room temperature and 350 °C, and the tensile strength are 446.9 MPa and 176.6 MPa, respectively. However, When the introduction of ZrB2 exceeds 3 wt%, large particle agglomeration alters the morphology and distribution of excess second phases along the grain boundaries, subsequently affecting the alloy's properties.
{"title":"The effects of in-situ ZrB2 nanoparticles and La on the microstructure and mechanical properties of the Al-5.4Cu-0.7Mg-0.6Ag alloy","authors":"Xiang Li , Anmin Li , Shier Wu , Qingping Sui , Zhengliang Wang , Zhuofang Huang , Shiwei Jiang","doi":"10.1016/j.vacuum.2025.114940","DOIUrl":"10.1016/j.vacuum.2025.114940","url":null,"abstract":"<div><div>Through optical microscope, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and tensile testing, The effects of in-situ ZrB<sub>2</sub> ceramic particles and rare earth La on the microstructures and mechanical properties of Al-5.4Cu-0.7Mg-0.6Ag alloys have been investigated. Additionally, their synergistic strengthening effect was analyzed. The results show that the Al<sub>6</sub>Cu<sub>6</sub>La phase formed after the addition of rare earth La affects the mechanical properties of the composite. With the introduction of La and ZrB<sub>2</sub> particles, the average grain size decreases to 28.8 μm, and the strength of the composite improves significantly. When the introduction of ZrB<sub>2</sub> reaches 3 wt%, the tensile properties are greatly improved at room temperature and 350 °C, and the tensile strength are 446.9 MPa and 176.6 MPa, respectively. However, When the introduction of ZrB<sub>2</sub> exceeds 3 wt%, large particle agglomeration alters the morphology and distribution of excess second phases along the grain boundaries, subsequently affecting the alloy's properties.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"246 ","pages":"Article 114940"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145842170","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 : 2026-03-01Epub Date: 2025-12-18DOI: 10.1016/j.vacuum.2025.115030
Jie Yu , Hua Shao , Junjie Li , Zemeng Feng , Longrui Xia , Rui Ge , Guobin Bai , Xiaobin He , Dianming Sun , Zhiqiang Li , Rui Chen , Yayi Wei
As integrated circuit technology node continues to advance, SiNx film deposition in evolving three-dimensional structures with higher integration density and large aspect ratios faces challenges from conformity and tunable film properties. This paper investigates the impact of incident energy and substrate temperature on the microstructural properties and surface morphology of SiNx thin film growth by plasma enhanced chemical vapor deposition process, on nanoscale silicon substrate with different aspect ratios. We conduct both experiments and molecular dynamics simulation to investigate the deposition performance of SiNx thin films. The results indicate that SiNx film microstructure will be more disordered as the temperature and energy increase. The density of SiNx film shows a significant dependence on the substrate temperature, when the temperature increases from 353 K to 673 K, density increases from 2.43 g/cm3 to 2.71 g/cm3. However, the kinetic energy increase does not result in a significant change in film density. We also observe that the substrate temperature exhibits little impact while gas kinetic energy significantly increases the deposition rate. Finally, we characterize the conformity of deposition on nanoscale structures by calculating step coverage. With larger open width, higher temperature and higher gas kinetic energy, the film conformity improves. These results may enable development of efficient manner for process optimization and film property tuning in advanced manufacturing.
{"title":"Molecular dynamics study of silicon nitride thin film growth on nanoscale structures by plasma enhanced chemical vapor deposition","authors":"Jie Yu , Hua Shao , Junjie Li , Zemeng Feng , Longrui Xia , Rui Ge , Guobin Bai , Xiaobin He , Dianming Sun , Zhiqiang Li , Rui Chen , Yayi Wei","doi":"10.1016/j.vacuum.2025.115030","DOIUrl":"10.1016/j.vacuum.2025.115030","url":null,"abstract":"<div><div>As integrated circuit technology node continues to advance, SiN<sub>x</sub> film deposition in evolving three-dimensional structures with higher integration density and large aspect ratios faces challenges from conformity and tunable film properties. This paper investigates the impact of incident energy and substrate temperature on the microstructural properties and surface morphology of SiN<sub>x</sub> thin film growth by plasma enhanced chemical vapor deposition process, on nanoscale silicon substrate with different aspect ratios. We conduct both experiments and molecular dynamics simulation to investigate the deposition performance of SiN<sub>x</sub> thin films. The results indicate that SiN<sub>x</sub> film microstructure will be more disordered as the temperature and energy increase. The density of SiN<sub>x</sub> film shows a significant dependence on the substrate temperature, when the temperature increases from 353 K to 673 K, density increases from 2.43 g/cm<sup>3</sup> to 2.71 g/cm<sup>3</sup>. However, the kinetic energy increase does not result in a significant change in film density. We also observe that the substrate temperature exhibits little impact while gas kinetic energy significantly increases the deposition rate. Finally, we characterize the conformity of deposition on nanoscale structures by calculating step coverage. With larger open width, higher temperature and higher gas kinetic energy, the film conformity improves. These results may enable development of efficient manner for process optimization and film property tuning in advanced manufacturing.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"246 ","pages":"Article 115030"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145792017","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 : 2026-03-01Epub Date: 2025-12-13DOI: 10.1016/j.vacuum.2025.115011
Yue Liang , Lixin Xia , Jia Yang , Yao Wang , Fei Wang , Bin Yang , Baoqiang Xu , Wenlong Jiang , Daofei Zhu
This study proposes a novel matte smelting-vacuum volatilization method for the efficient separation of antimony and gold, which utilizes a low-melting-point B2O3-Al2O3-CaO-SiO2 slag system for matte smelting, coupled with vacuum volatilization to achieve efficient enrichment and recovery. The process first captures gold via matte smelting, producing a gold-rich antimony matte and slag. This step achieved an antimony recovery rate of 95.48%, with gold being almost entirely enriched in the matte. Subsequently, vacuum volatilization of the gold-containing antimony matte was conducted at 1073 K and 1 Pa, leveraging differences in elemental vapor pressures to achieve a 99.97% separation rate of antimony. The overall direct recovery of antimony reached 97.05%. The gold content in the residual concentrate was enriched from 18 g/t in the raw ore to 174 g/t, representing an 8.7-fold increase. The key innovation of this process is the integration of matte smelting with vacuum volatilization, which facilitates high recovery rates. This approach overcomes the limitations of traditional methods, providing an efficient and environmentally friendly alternative for processing refractory antimony-gold concentrates.
{"title":"Matte smelting and vacuum volatilization: An integrated approach for efficient antimony-gold separation","authors":"Yue Liang , Lixin Xia , Jia Yang , Yao Wang , Fei Wang , Bin Yang , Baoqiang Xu , Wenlong Jiang , Daofei Zhu","doi":"10.1016/j.vacuum.2025.115011","DOIUrl":"10.1016/j.vacuum.2025.115011","url":null,"abstract":"<div><div>This study proposes a novel matte smelting-vacuum volatilization method for the efficient separation of antimony and gold, which utilizes a low-melting-point B<sub>2</sub>O<sub>3</sub>-Al<sub>2</sub>O<sub>3</sub>-CaO-SiO<sub>2</sub> slag system for matte smelting, coupled with vacuum volatilization to achieve efficient enrichment and recovery. The process first captures gold via matte smelting, producing a gold-rich antimony matte and slag. This step achieved an antimony recovery rate of 95.48%, with gold being almost entirely enriched in the matte. Subsequently, vacuum volatilization of the gold-containing antimony matte was conducted at 1073 K and 1 Pa, leveraging differences in elemental vapor pressures to achieve a 99.97% separation rate of antimony. The overall direct recovery of antimony reached 97.05%. The gold content in the residual concentrate was enriched from 18 g/t in the raw ore to 174 g/t, representing an 8.7-fold increase. The key innovation of this process is the integration of matte smelting with vacuum volatilization, which facilitates high recovery rates. This approach overcomes the limitations of traditional methods, providing an efficient and environmentally friendly alternative for processing refractory antimony-gold concentrates.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"246 ","pages":"Article 115011"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145792014","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 : 2026-03-01Epub Date: 2025-12-18DOI: 10.1016/j.vacuum.2025.115031
Meng Gao , Youchen Sun , Aqing Chen , Jun Zhang
Doping behavior of Cobalt (Co) in diamond was investigated by using density functional theory (DFT). Formation energies, work functions, and charge distributions were calculated for Co atoms substituted at different depths in the (111) and (220) planes. The results show that Co incorporation is energetically favorable in the shallow layers of both surfaces, but becomes progressively less stable at greater depths. On both crystal planes, Co doping reduces the work function by approximately 0.25 eV, suggesting enhanced electron emission and higher surface reactivity. Charge density analysis further reveals significant electron transfer between Co and neighboring carbon atoms, forming mixed covalent-ionic bonds and inducing local lattice distortions. These electronic and structural modifications highlight the potential of Co-doped diamond as a tunable material for catalytic and electronic applications. The findings provide theoretical guidance for future experimental studies aimed at exploiting transition-metal doping to tailor diamond's functional properties.
{"title":"First-principles calculations on the electronic structure of Co-doped diamond","authors":"Meng Gao , Youchen Sun , Aqing Chen , Jun Zhang","doi":"10.1016/j.vacuum.2025.115031","DOIUrl":"10.1016/j.vacuum.2025.115031","url":null,"abstract":"<div><div>Doping behavior of Cobalt (Co) in diamond was investigated by using density functional theory (DFT). Formation energies, work functions, and charge distributions were calculated for Co atoms substituted at different depths in the (111) and (220) planes. The results show that Co incorporation is energetically favorable in the shallow layers of both surfaces, but becomes progressively less stable at greater depths. On both crystal planes, Co doping reduces the work function by approximately 0.25 eV, suggesting enhanced electron emission and higher surface reactivity. Charge density analysis further reveals significant electron transfer between Co and neighboring carbon atoms, forming mixed covalent-ionic bonds and inducing local lattice distortions. These electronic and structural modifications highlight the potential of Co-doped diamond as a tunable material for catalytic and electronic applications. The findings provide theoretical guidance for future experimental studies aimed at exploiting transition-metal doping to tailor diamond's functional properties.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"246 ","pages":"Article 115031"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145792011","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 : 2026-03-01Epub Date: 2025-12-27DOI: 10.1016/j.vacuum.2025.115054
Yunpeng Wang , Junjie Gui , Lidan Wang , Yunpeng Xu , Can Wang , Xue Zhang , Qixin Zhuang , Zisheng Su , Yaoming Xiao
The high resistance of large-area conductive glass substrate is an important factor limiting the fill factor (FF) improvement of large-area perovskite solar cells (PSCs). Herein, we electrochemically deposit a low-resistance tin (Sn) grid electrode on the fluorine-doped tin oxide (FTO) substrate by laser etching and space-constrained growth (Scg) methods, and then in situ prepare a silicon oxide (SiOX) protective film on the Sn grid electrode by using tetraethyl orthosilicate to receive FTO-SnScg-SiOX electrode. The laser etching method can obtain any electrode pattern we want. Scg method can control the thickness of Sn grid electrode, which influences the subsequent film preparations. SiOX can protect Sn grid electrode and avoid the direct contact between Sn grid electrode and the perovskite. As a result, 1.00 cm2 PSC based on FTO-SnScg-SiOX achieves the optimum efficiency of 24.38 % with the highest FF of 82.13 %, and maintains 92.01 % of its original efficiency after 1500 h. These methods can also be extended to a large-area PSC module with an active area of 60.54 cm2 and an optimized PCE of 21.24 %. The combined strategy presented in this paper is conducive to further improving the efficiency and area of PSCs, thereby accelerating the industrialization of large-area PSCs.
{"title":"Space-confined growth and silicon oxide film protection of tin grid electrodes for large-area and stable perovskite solar cells","authors":"Yunpeng Wang , Junjie Gui , Lidan Wang , Yunpeng Xu , Can Wang , Xue Zhang , Qixin Zhuang , Zisheng Su , Yaoming Xiao","doi":"10.1016/j.vacuum.2025.115054","DOIUrl":"10.1016/j.vacuum.2025.115054","url":null,"abstract":"<div><div>The high resistance of large-area conductive glass substrate is an important factor limiting the fill factor (FF) improvement of large-area perovskite solar cells (PSCs). Herein, we electrochemically deposit a low-resistance tin (Sn) grid electrode on the fluorine-doped tin oxide (FTO) substrate by laser etching and space-constrained growth (Scg) methods, and then in situ prepare a silicon oxide (SiO<sub>X</sub>) protective film on the Sn grid electrode by using tetraethyl orthosilicate to receive FTO-Sn<sub>Scg</sub>-SiO<sub>X</sub> electrode. The laser etching method can obtain any electrode pattern we want. Scg method can control the thickness of Sn grid electrode, which influences the subsequent film preparations. SiO<sub>X</sub> can protect Sn grid electrode and avoid the direct contact between Sn grid electrode and the perovskite. As a result, 1.00 cm<sup>2</sup> PSC based on FTO-Sn<sub>Scg</sub>-SiO<sub>X</sub> achieves the optimum efficiency of 24.38 % with the highest FF of 82.13 %, and maintains 92.01 % of its original efficiency after 1500 h. These methods can also be extended to a large-area PSC module with an active area of 60.54 cm<sup>2</sup> and an optimized PCE of 21.24 %. The combined strategy presented in this paper is conducive to further improving the efficiency and area of PSCs, thereby accelerating the industrialization of large-area PSCs.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"246 ","pages":"Article 115054"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145885206","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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