IF 3.8 2区材料科学

Vacuum Pub Date : 2025-06-07 DOI: 10.1016/j.vacuum.2025.114491

Abdul Whab, Shahin Parveen, Nidhi Bhatt, Pumlianmunga

{"title":"Elucidating the phase change memory properties of (GeTe)1-x(GeSe2)x (0 ≤ x ≤ 0.21) films","authors":"Abdul Whab, Shahin Parveen, Nidhi Bhatt, Pumlianmunga","doi":"10.1016/j.vacuum.2025.114491","DOIUrl":"10.1016/j.vacuum.2025.114491","url":null,"abstract":"<div><div>GeSe<sub>2</sub>-doped GeTe phase change memory alloys are considered for high-temperature applications. Films of compositions (GeTe)<sub>1-<em>x</em></sub>(GeSe<sub>2</sub>)<sub><em>x</em></sub> (x = 0, 0.07, 0.14, 0.21) showed an increase in the crystallization temperature (T<sub>c</sub>) from 170 °C to 258 °C after doping with GeSe<sub>2</sub>, which is caused by an improvement in the activation energy. Incorporation of GeSe<sub>2</sub> increases the amorphous as well as crystalline resistances, resulting in the decrease in threshold current (I<sub>th</sub>) from 0.9 mA to 0.4 mA. The 10 years of data retention temperature have been increased from 96 °C to 128 °C with a corresponding increase in the activation energy from 2.43 eV to 2.73 eV. The amorphous phase crystallized to a rhombohedral structure with no phase separation, and the crystallite size decreases with the increase in the GeSe<sub>2</sub> concentration. X-ray photoelectron spectroscopy (XPS) confirmed the presence of stronger Ge-Se bonds, which increase the localization of charge carriers, resulting in the increase in optical band gap. Increased thermal stability (high T<sub>c</sub>), high electrical resistance contrast between the amorphous and crystalline states, high crystalline resistance, and single-phase GeTe are characteristics of phase change memory (PCM) material for high-temperature applications.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"240 ","pages":"Article 114491"},"PeriodicalIF":3.8,"publicationDate":"2025-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144262213","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

Effects of crystal structure and surface roughness in sputtering of metals by Ar ions 氩离子溅射金属时晶体结构和表面粗糙度的影响

IF 3.8 2区材料科学

Vacuum Pub Date : 2025-06-07 DOI: 10.1016/j.vacuum.2025.114489

V.I. Shulga

引用次数: 0

Surface patterns shaped by additives in crystals 晶体中添加剂形成的表面图案

IF 3.8 2区材料科学

Vacuum Pub Date : 2025-06-06 DOI: 10.1016/j.vacuum.2025.114431

M.A. Chabowska, M.A. Załuska-Kotur

{"title":"Surface patterns shaped by additives in crystals","authors":"M.A. Chabowska, M.A. Załuska-Kotur","doi":"10.1016/j.vacuum.2025.114431","DOIUrl":"10.1016/j.vacuum.2025.114431","url":null,"abstract":"<div><div>One technique for creating semiconductor crystals with new, desired properties involves replacing some atoms in the crystal lattice with additives — atoms of a different type. This substitution not only alters the bulk properties of the crystal but also affects the patterns formed on its surface. A surface that is smooth and regular in a uniform crystal can become bunched or meandered under the same growth conditions if some atoms are replaced by additives. The Vicinal Cellular Automaton (VicCA) model is used to study this behavior, analyzing the mechanism of pattern formation when additives are introduced into the system. It has also been shown that the newly formed structures resulting from the presence of additives can be smoothed by applying successive layers of a homogeneous composition on top for a sufficiently long time. Additives can also act as smoothing agents for bunched or meandered surface patterns that develop in a homogeneous crystal. However, their effectiveness diminishes for spatially extended patterns such as nanowires (NWs). Typically, when homogeneous crystal layers are applied to spatial structures, the resulting surface is not entirely smoothed but instead transforms into a distinct shape. This phenomenon is demonstrated, and its underlying mechanism is thoroughly analyzed.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"240 ","pages":"Article 114431"},"PeriodicalIF":3.8,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144242937","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

Synthesis and characterization of Cu2O/ZnO heterojunction for photocatalytic removal of methylene blue 光催化去除亚甲基蓝用Cu2O/ZnO异质结的合成与表征

IF 3.8 2区材料科学

Vacuum Pub Date : 2025-06-06 DOI: 10.1016/j.vacuum.2025.114482

Jayaprakash Avinash, S.P. Vijaya Chamundeeswari

{"title":"Synthesis and characterization of Cu2O/ZnO heterojunction for photocatalytic removal of methylene blue","authors":"Jayaprakash Avinash, S.P. Vijaya Chamundeeswari","doi":"10.1016/j.vacuum.2025.114482","DOIUrl":"10.1016/j.vacuum.2025.114482","url":null,"abstract":"<div><div>In this work, a Cu<sub>2</sub>O/ZnO heterojunction photocatalyst was synthesized via an in-situ precipitation method and characterized to assess its potential for photocatalytic dye degradation under visible light irradiation. Structural analysis using X-ray diffraction (XRD) confirmed the crystalline phases of Cu<sub>2</sub>O and ZnO, while Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) verified the presence of functional groups and elemental states, respectively. Morphological investigations using FESEM and TEM revealed the uniform anchoring of ZnO nanoparticles on Cu<sub>2</sub>O microcubes, facilitating effective heterojunction formation. UV–visible diffuse reflectance spectroscopy (UV-DRS) indicated that the Cu<sub>2</sub>O/ZnO composite exhibited a narrowed band gap, enabling superior visible-light absorption compared to its pristine counterparts. Photocatalytic tests demonstrated a degradation efficiency of 73.3 % for MB within 60 min of visible-light, significantly outperforming individual Cu<sub>2</sub>O and ZnO. The study provides valuable insights into the interfacial charge dynamics and highlights a promising strategy for improving photocatalytic efficiency via heterostructure.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"240 ","pages":"Article 114482"},"PeriodicalIF":3.8,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144231437","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

Enhancement of surface quality and corrosion resistance in 321 stainless steel by electrochemical machining 电化学加工提高321不锈钢表面质量和耐蚀性

IF 3.8 2区材料科学

Vacuum Pub Date : 2025-06-06 DOI: 10.1016/j.vacuum.2025.114487

ManFu Wang, Cong Liu, GaoYuan Bai, HongYi Liu, YaBo Liu, DongXu Fan, ZeXing Wang, GuiBing Pang

{"title":"Enhancement of surface quality and corrosion resistance in 321 stainless steel by electrochemical machining","authors":"ManFu Wang, Cong Liu, GaoYuan Bai, HongYi Liu, YaBo Liu, DongXu Fan, ZeXing Wang, GuiBing Pang","doi":"10.1016/j.vacuum.2025.114487","DOIUrl":"10.1016/j.vacuum.2025.114487","url":null,"abstract":"<div><div>Electrochemical machining technology was applied to treat the surface of 321 stainless steel. The surface roughness values were measured and the surface morphologies were observed. The corrosion resistance of the samples was compared before and after electrochemical machining treatment. The characteristics and composition of the passive films were detected. The results showed that electrochemical machining was beneficial for obtaining high-quality surfaces. Following a processing time of 15min, the surface roughness reached 0.24 μm. The outcomes of the corrosion resistance tests demonstrated that the mechanically machined sample was severely corroded, whereas the sample subjected to electrochemical machining experienced little obvious macroscopic corrosion. The electrochemical treatment increased the corrosion potential and decreased the corrosion current density in the polarization curve of 321 stainless steel. The high-resolution projective electron microscopy results indicated that there existed amorphous passive films on the sample surface and the thickness of the passivation layers increased due to electrochemical machining. By X-ray photoelectron spectroscopy, following electrochemical machining, there was a notable enrichment of chromium compounds in the passive films and the ratio of Cr<sub>2</sub>O<sub>3</sub>/Cr(OH)<sub>3</sub> increased. The dense Cr<sub>2</sub>O<sub>3</sub> component played a dominant role and served to stabilize the passive films, thereby enhancing the corrosion resistance of 321 stainless steel.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"240 ","pages":"Article 114487"},"PeriodicalIF":3.8,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144242938","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

Porous titanium nitride thin film for enhanced biosensing applications 多孔氮化钛薄膜增强生物传感应用

IF 3.8 2区材料科学

Vacuum Pub Date : 2025-06-06 DOI: 10.1016/j.vacuum.2025.114486

Marysteven Uchegbu , Nizar BenMoussa , Etienne Herth , Issam Nour , Lionel Rousseau , Gaelle Lissorgues

{"title":"Porous titanium nitride thin film for enhanced biosensing applications","authors":"Marysteven Uchegbu , Nizar BenMoussa , Etienne Herth , Issam Nour , Lionel Rousseau , Gaelle Lissorgues","doi":"10.1016/j.vacuum.2025.114486","DOIUrl":"10.1016/j.vacuum.2025.114486","url":null,"abstract":"<div><div>The development of electrochemical (EC) biosensors requires materials with superior stability, sensitivity and adaptability in complex biological settings. Traditional metal oxide-based EC sensors are often limited by matrix interferences, impacting sensitivity. Here, we present porous titanium nitride (p-TiN) thin film as a novel microelectrode (ME) material designed to overcome these limitations. Using a combination of Direct Current (DC) reactive sputtering and controlled isotropic wet etching at varied etchant ratios, we fabricated p-TiN thin films with tailored porosity, confirmed by comprehensive characterization techniques, including Scanning Electron Microscopy (SEM) coupled with Energy Dispersive Spectroscopy (EDS), Transmission Electron Microscopy (TEM) coupled with EDS Mapping, Raman Spectroscopy, Photoluminescence (PL), and Fourier Transform Infrared Spectroscopy (FTIR). Brunauer-Emmett-Teller (BET) analysis further validated the mesoporous structure, enhancing both wettability and hydrophilicity crucial for biosensing interfaces. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry verified the material's stability, purity and consistent capacitive behavior, with an effective capacitance of 10 μF across all scan rates. The p-TiN thin film electrode demonstrated low impedance, reinforcing its suitability and robustness for high-sensitivity applications. These findings establish porous titanium nitride thin film as a transformative material for next-generation biosensors, offering significant improvements in sensitivity, selectivity and durability for health and environmental applications.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"240 ","pages":"Article 114486"},"PeriodicalIF":3.8,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144242564","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

Synthesis of high-purity aluminum via carbothermic reduction in microwave plasma for trimethylaluminum production 微波等离子体碳热还原法制备高纯铝的研究

IF 3.8 2区材料科学

Vacuum Pub Date : 2025-06-06 DOI: 10.1016/j.vacuum.2025.114484

Alexander Logunov, Andrey Vorotyntsev, Igor Prokhorov, Alexey Maslov, Artem Belousov, Ivan Zanozin, Evgeniya Logunova, Artem Kulikov, Vladimir Vorotyntsev, Sergei Zelentsov, Anton Petukhov, Olga Kazarina, Sergey Suvorov

{"title":"Synthesis of high-purity aluminum via carbothermic reduction in microwave plasma for trimethylaluminum production","authors":"Alexander Logunov, Andrey Vorotyntsev, Igor Prokhorov, Alexey Maslov, Artem Belousov, Ivan Zanozin, Evgeniya Logunova, Artem Kulikov, Vladimir Vorotyntsev, Sergei Zelentsov, Anton Petukhov, Olga Kazarina, Sergey Suvorov","doi":"10.1016/j.vacuum.2025.114484","DOIUrl":"10.1016/j.vacuum.2025.114484","url":null,"abstract":"<div><div>High-purity aluminum is extensively utilized in metallurgy, microelectronics, and chemical synthesis. In this study, a method involving the carbothermic reduction of aluminum powder in a microwave plasma discharge was employed, resulting in the formation of valuable organic products such as synthesis gas, acetylene, and benzene. The aluminum powder was characterized using inductively coupled plasma mass spectrometry (ICP-MS), scanning electron microscopy (SEM), and powder X-ray diffraction (XRD). The yield of by-products was analyzed using gas chromatography coupled with a mass spectrometer, along with optical emission spectroscopy of the plasma discharge. The high-purity aluminum powder obtained from the plasma reduction was subsequently used to synthesize oxygen-free trimethylaluminum (TMA 99.9995 % main substance by weight). Notably, TMA was synthesized in a single vacuum cycle without system depressurization, enhancing the purity of the final product (7N by trace metal analyses). The synthesized trimethylaluminum was further analyzed using gas chromatography, gas chromatography-mass spectrometry (GC-MS), and ICP-MS.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"240 ","pages":"Article 114484"},"PeriodicalIF":3.8,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144242941","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 aging on the ball milling of high-strength Ti2AlNb-based alloy 时效对高强度ti2alnb基合金球磨性能的影响

IF 3.8 2区材料科学

Vacuum Pub Date : 2025-06-06 DOI: 10.1016/j.vacuum.2025.114485

K.S. Senkevich

引用次数: 0

Research on strategies for optimizing small-sized ion beam performance to achieve figuring of mid-spatial frequency errors on complex curved mirrors 优化小尺寸离子束性能以实现复杂曲面镜中频误差计算的策略研究

IF 3.8 2区材料科学

Vacuum Pub Date : 2025-06-06 DOI: 10.1016/j.vacuum.2025.114480

Meng Liu , Xiaoqiang Peng , Jie Hu , Yiang Zhang , Chaoliang Guan , Hao Hu , Hongyu Zou , Chunyang Du

{"title":"Research on strategies for optimizing small-sized ion beam performance to achieve figuring of mid-spatial frequency errors on complex curved mirrors","authors":"Meng Liu , Xiaoqiang Peng , Jie Hu , Yiang Zhang , Chaoliang Guan , Hao Hu , Hongyu Zou , Chunyang Du","doi":"10.1016/j.vacuum.2025.114480","DOIUrl":"10.1016/j.vacuum.2025.114480","url":null,"abstract":"<div><div>Complex curved mirrors, featuring high design flexibility, strong aberration-correcting capabilities, and compact structures, are widely utilized in modern optical systems. Currently, ion beam figuring has achieved sub-nanometer precision. However, with the growth in the clear aperture and steepness of mirrors, stringent requirements are set for process conditions and polishing tools, and the correction of mid-spatial frequency (MSF) errors using small-sized ion beams faces great challenges. This paper introduces a method for correcting MSF errors using a small-sized ion beam generated by a conical diaphragm, and its geometric design principles are explained with a simulation model. Simulation results show that selecting appropriate geometric dimensions can effectively adjust the processing distance and significantly improve the material removal rate. Using this method, a small-sized ion beam with a full width at half maximum of 1.01 mm and a processing distance of 22.32 mm is obtained, and its peak energy is 29 times that of a traditional flat diaphragm. Finally, the form error of a complex curved mirror with a clear aperture of Φ45–210 mm and a sag difference of 16.9 mm was corrected to 3.55 nm RMS. The proposed method provides theoretical and technical support for the manufacturing of optical components with nanometer-level precision.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"240 ","pages":"Article 114480"},"PeriodicalIF":3.8,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144271492","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

Additive manufacturing of TiC-reinforced FeCoCrNiMn high-entropy alloy composites with exceptional strength and ductility 具有优异强度和延展性的tic增强feccrnimn高熵合金复合材料的增材制造

IF 3.8 2区材料科学

Vacuum Pub Date : 2025-06-05 DOI: 10.1016/j.vacuum.2025.114483

Hamza Osman , Jie Pan , Pengcheng Zhang , Cheng Zhang , Xin Zhang , Bailing An , Lin Liu

引用次数: 0

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