Crystals最新文献_第7页

Localized Structural and Electronic Perturbations Induced by Mono-Vacancy in MgH2: A Comprehensive First-Principles Investigation MgH2 单空位诱发的局部结构和电子扰动：全面的第一性原理研究

IF 2.7 4区材料科学

Crystals Pub Date : 2024-08-24 DOI: 10.3390/cryst14090750

Lei Bao, Jun Shi, Qichi Le

{"title":"Localized Structural and Electronic Perturbations Induced by Mono-Vacancy in MgH2: A Comprehensive First-Principles Investigation","authors":"Lei Bao, Jun Shi, Qichi Le","doi":"10.3390/cryst14090750","DOIUrl":"https://doi.org/10.3390/cryst14090750","url":null,"abstract":"In the pursuit of sustainable energy, magnesium hydride (MgH2) stands out as a promising candidate for hydrogen storage due to its high capacity. Nevertheless, its high thermodynamic stability necessitates elevated operating temperatures, thereby hindering practical applications. To mitigate this limitation, our study employs a defect engineering approach by introducing a mono-vacancy to decrease its thermodynamic stability. Utilizing first-principles density functional theory calculations, we investigate the influence of a mono-vacancy on the structural and electronic properties of MgH2 crystal. Introducing the defect results in a 0.57% contraction of the a/b lattice parameters and a 1.03% expansion along the c-axis, causing lattice distortion. Electronically, the band gap narrows by 0.67 eV, indicating an increase in metallic character. We observe a distinct vacancy-affected zone, characterized by substantial alterations in electron density within a 26.505 Å3 volume and modifications to the potential energy distribution encompassing a 19.514 Å3 volume. The mono-vacancy enhances the polarity of the Mg-H bonds and maximally decreases the bond energy by 0.065 eV. A localized high-energy region of 0.354 eV emerges, functioning as an energy barrier to atomic diffusion. This energy barrier is encompassed by low-energy pathways, potentially facilitating H atom migration within the MgH2 crystal.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"27 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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

The First Crystal Structure of an Anti-Geometric Homoleptic Zinc Complex from an Unsymmetric Curcuminoid Ligand 非对称莪术配体反几何同色锌复合物的首个晶体结构

IF 2.7 4区材料科学

Crystals Pub Date : 2024-08-24 DOI: 10.3390/cryst14090751

Marco A. Obregón Mendoza, Gabriela Marmolejo Escamilla, Rosario Tavera-Hernández, Rubén Sánchez-Obregón, Rubén A. Toscano, Raúl G. Enríquez

引用次数: 0

Electron Beam Welding of Copper and Aluminum Alloy with Magnetron Sputtered Titanium Filler 铜和铝合金与磁控溅射钛填充物的电子束焊接

IF 2.7 4区材料科学

Crystals Pub Date : 2024-08-24 DOI: 10.3390/cryst14090752

Darina Kaisheva, Georgi Kotlarski, Maria Ormanova, Angel Anchev, Vladimir Dunchev, Borislav Stoyanov, Stefan Valkov

{"title":"Electron Beam Welding of Copper and Aluminum Alloy with Magnetron Sputtered Titanium Filler","authors":"Darina Kaisheva, Georgi Kotlarski, Maria Ormanova, Angel Anchev, Vladimir Dunchev, Borislav Stoyanov, Stefan Valkov","doi":"10.3390/cryst14090752","DOIUrl":"https://doi.org/10.3390/cryst14090752","url":null,"abstract":"In this work, the results from the electron beam welding of copper and Al6082T6 aluminum alloy with a titanium filler are presented. The influence of the filler on the structure and mechanical properties of the welded joint is studied in comparison with one without filler. The X-ray diffraction (XRD) method was used to obtain the phase composition of the welded joints. Scanning electron microscopy (SEM) was used for the study of the microstructure of the welds. Energy-dispersive X-ray spectroscopy (EDX) was applied to investigate the chemical composition. The mechanical properties were studied by means of microhardness measurements and tensile tests. A three-phase structure was obtained in the fusion zone consisting of an aluminum matrix, an intermetallic compound CuAl2, and pure copper. The application of Ti filler significantly decreased the amount of molten copper introduced in the molten pool and the number of intermetallic compounds (IMCs). This improved the strength of the joint; however, some quantity of IMCs was still present in the zone of fusion (FZ), which reflected the microhardness of the samples. The application of a titanium filler resulted in refining the electron beam weld’s structure. The finer structure and the reduced amount of the brittle intermetallic phases has led to an increase in the strength of the joint.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"20 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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

Surface Recrystallization Model of Fully Amorphized C3H5-Molecular-Ion-Implanted Silicon Substrate 完全非晶化 C3H5 分子离子注入硅衬底的表面再结晶模型

IF 2.7 4区材料科学

Crystals Pub Date : 2024-08-23 DOI: 10.3390/cryst14090748

Koji Kobayashi, Ryosuke Okuyama, Takeshi Kadono, Ayumi Onaka-Masada, Ryo Hirose, Akihiro Suzuki, Sho Nagatomo, Yoshihiro Koga, Koji Sueoka, Kazunari Kurita

{"title":"Surface Recrystallization Model of Fully Amorphized C3H5-Molecular-Ion-Implanted Silicon Substrate","authors":"Koji Kobayashi, Ryosuke Okuyama, Takeshi Kadono, Ayumi Onaka-Masada, Ryo Hirose, Akihiro Suzuki, Sho Nagatomo, Yoshihiro Koga, Koji Sueoka, Kazunari Kurita","doi":"10.3390/cryst14090748","DOIUrl":"https://doi.org/10.3390/cryst14090748","url":null,"abstract":"The surface recrystallization model of the fully amorphized C3H5-molecular-ion-implanted silicon (Si) substrate is investigated. Transmission electron microscopy is performed to observe the amorphous/crystalline interface near the C3H5-molecular-ion-implanted Si substrate surface after the subsequent recovery thermal annealing treatment. At a depth of high-concentration carbon of approximately 4.8 × 1020 atoms/cm3, recrystallization from the crystalline template to the surface by solid-phase epitaxial growth is partially delayed, and the activation energy was estimated to be 2.79 ± 0.14 eV. The change in the crystalline fraction of the fully amorphized C3H5-molecular-ion-implanted Si substrate surface is quantitatively evaluated from the binding energy of Si 2p spectra by X-ray photoelectron spectroscopy. Using the Kolmogorov–Johnson–Mehl–Avrami equation, the surface recrystallization of the fully amorphized C3H5-molecular-ion-implanted Si substrate is assumed to proceed two-dimensionally, and its activation energy is obtained as 2.71 ± 0.28 eV without the effect of carbon. Technology computer-aided design (TCAD) process simulations calculate recrystallization under the effect of high-concentration carbon and demonstrate the reach of some crystalline regions to the surface first. In the fully amorphized C3H5-molecular-ion-implanted Si substrate, it is considered that recrystallization is partially delayed due to high-concentration carbon and surface recrystallization proceeds two-dimensionally from some crystalline regions reaching the surface first.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"8 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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

Research Viewpoint on Performance Enhancement for Very-High-Cycle Fatigue of Ti-6Al-4V Alloys via Laser-Based Powder Bed Fusion 通过激光粉末床熔融技术提高 Ti-6Al-4V 合金超高循环疲劳性能的研究观点

IF 2.7 4区材料科学

Crystals Pub Date : 2024-08-23 DOI: 10.3390/cryst14090749

Chun Gao, Yang Zhang, Jingjiang Jiang, Rui Fu, Leiming Du, Xiangnan Pan

{"title":"Research Viewpoint on Performance Enhancement for Very-High-Cycle Fatigue of Ti-6Al-4V Alloys via Laser-Based Powder Bed Fusion","authors":"Chun Gao, Yang Zhang, Jingjiang Jiang, Rui Fu, Leiming Du, Xiangnan Pan","doi":"10.3390/cryst14090749","DOIUrl":"https://doi.org/10.3390/cryst14090749","url":null,"abstract":"Additive manufacturing (AM) or 3D printing is a promising industrial technology that enables rapid prototyping of complex configurations. Powder Bed Fusion (PBF) is one of the most popular AM techniques for metallic materials. Until today, only a few metals and alloys are available for AM, e.g., titanium alloys, the most common of which is Ti-6Al-4V. After optimization of PBF parameters, with or without post processing such as heat treatment or hot isostatic pressing, the printed titanium alloy can easily reach tensile strengths of over 1100 MPa due to the quick cooling of the AM process. However, attributed to the unique features of metallurgical defects and microstructure introduced by this AM process, their fatigue strength has been low, often less than 30% of the tensile strength, especially in very-high-cycle regimes, i.e., failure life beyond 107 cycles. Here, based on our group’s research on the very-high-cycle fatigue (VHCF) of additively manufactured (AMed) Ti-6Al-4V alloys, we have refined the basic quantities of porosity, metallurgical defects, and the AMed microstructure, summarized the main factors limiting their VHCF strengths, and suggested possible ways to improve VHCF performance.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"11 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202552","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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

Influence of Ni Doping on Oxygen Vacancy-Induced Changes in Structural and Chemical Properties of CeO2 Nanorods 掺杂镍对氧空位引起的 CeO2 纳米棒结构和化学性质变化的影响

IF 2.7 4区材料科学

Crystals Pub Date : 2024-08-22 DOI: 10.3390/cryst14080746

Yuanzheng Zhu, Weixia Wang, Gejunxiang Chen, Huyi Li, Yuedie Zhang, Chang Liu, Hao Wang, Ping Cheng, Chunguang Chen, Gimyeong Seong

{"title":"Influence of Ni Doping on Oxygen Vacancy-Induced Changes in Structural and Chemical Properties of CeO2 Nanorods","authors":"Yuanzheng Zhu, Weixia Wang, Gejunxiang Chen, Huyi Li, Yuedie Zhang, Chang Liu, Hao Wang, Ping Cheng, Chunguang Chen, Gimyeong Seong","doi":"10.3390/cryst14080746","DOIUrl":"https://doi.org/10.3390/cryst14080746","url":null,"abstract":"In recent years, cerium dioxide (CeO2) has attracted considerable attention owing to its remarkable performance in various applications, including photocatalysis, fuel cells, and catalysis. This study explores the effect of nickel (Ni) doping on the structural, thermal, and chemical properties of CeO2 nanorods, particularly focusing on oxygen vacancy-related phenomena. Utilizing X-ray powder diffraction (XRD), alterations in crystal structure and peak shifts were observed, indicating successful Ni doping and the formation of Ni2O3 at higher doping levels, likely due to non-equilibrium reactions. Thermal gravimetric analysis (TGA) revealed changes in oxygen release mechanisms, with increasing Ni doping resulting in the release of lattice oxygen at lower temperatures. Raman spectroscopy corroborated these findings by identifying characteristic peaks associated with oxygen vacancies, facilitating the assessment of Ni doping levels. Ni-doped CeO2 can catalyze the ultrasonic degradation of methylene blue, which has good application prospects for catalytic ultrasonic degradation of organic pollutants. Overall, this study underscores the substantial impact of Ni doping on CeO2 nanorods, shedding light on tailored catalytic applications through the modulation of oxygen vacancies while preserving the nanorod morphology.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"4 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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

Magnetic Flux Concentration Technology Based on Soft Magnets and Superconductors 基于软磁和超导体的磁通量浓缩技术

IF 2.7 4区材料科学

Crystals Pub Date : 2024-08-22 DOI: 10.3390/cryst14080747

Yue Wu, Liye Xiao, Siyuan Han, Jiamin Chen

引用次数: 0

The Unusual Functional Role of Protein Flexibility in Photosynthetic Light Harvesting: Protein Dynamics Studied Using Neutron Scattering 蛋白质柔性在光合作用光收集中的非同寻常的功能作用：利用中子散射研究蛋白质动力学

IF 2.7 4区材料科学

Crystals Pub Date : 2024-08-21 DOI: 10.3390/cryst14080743

Maksym Golub, Jörg Pieper

{"title":"The Unusual Functional Role of Protein Flexibility in Photosynthetic Light Harvesting: Protein Dynamics Studied Using Neutron Scattering","authors":"Maksym Golub, Jörg Pieper","doi":"10.3390/cryst14080743","DOIUrl":"https://doi.org/10.3390/cryst14080743","url":null,"abstract":"In addition to investigations of the three-dimensional protein structure, information on the dynamical properties of proteins is indispensable for an understanding of protein function in general. Correlations between protein dynamics and function are typically anticipated when both molecular mobility and function are concurrently affected under specific temperatures or hydration conditions. In contrast, excitation energy transfer within the major photosynthetic light-harvesting complex II (LHC II) presents an atypical case, as it remains fully operational even at cryogenic temperatures, primarily depending on the interactions between electronic states and involving harmonic protein vibrations only. This review summarizes recent work on vibrational and conformational protein dynamics of LHC II and directly relates these findings to its light-harvesting function. In addition, we give a comprehensive introduction into the use of neutron spectroscopy and molecular dynamics simulations to investigate the protein dynamics of photosynthetic protein complexes in solution, which is information complementary to that obtained by protein crystallography.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"53 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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

Ferroelectric and Structural Properties of Cobalt-Doped Lead Ferrite Thin Films Formed by Reactive Magnetron Sputtering 反应磁控溅射法形成的掺钴铅铁氧体薄膜的铁电性质和结构特性

IF 2.7 4区材料科学

Crystals Pub Date : 2024-08-12 DOI: 10.3390/cryst14080721

Benas Beklešovas, Vytautas Stankus, Aleksandras Iljinas, Liutauras Marcinauskas

{"title":"Ferroelectric and Structural Properties of Cobalt-Doped Lead Ferrite Thin Films Formed by Reactive Magnetron Sputtering","authors":"Benas Beklešovas, Vytautas Stankus, Aleksandras Iljinas, Liutauras Marcinauskas","doi":"10.3390/cryst14080721","DOIUrl":"https://doi.org/10.3390/cryst14080721","url":null,"abstract":"Cobalt-doped lead ferrite (Pb2Fe2O5) thin films were deposited by reactive magnetron sputtering. The influence of the cobalt concentration and synthesis temperature on the structure, phase composition and ferroelectric properties of Pb2Fe2O5 thin films was investigated. It was determined that the increase in deposition temperature increased the grain size and density of the Co-doped PFO thin films. The XRD data demonstrated that the Co-doped Pb2Fe2O5 thin films consisted of Pb2Fe2O5 and PbO phases with a low amount of CoO and Co3O4 phases. The increase in the cobalt concentration in the Pb2Fe2O5 films slightly enhanced the cobalt oxide phase content. Polarization dependence on electric field measurement demonstrated that the highest ferroelectric properties of the Co-doped Pb2Fe2O5 films were obtained when the synthesis was performed at 550 °C temperatures. The increase in the cobalt concentration in the films enhanced the remnant polarization and coercive field values. It was found that the Co-doped Pb2Fe2O5 film deposited at 550 °C temperature and containing 10% cobalt had the highest remnant polarization (72 µC/cm2) and coercive electric field (105 kV/cm).","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"20 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141934668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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

Early Stages of Crack Nucleation Mechanism in Fe39Mn20Co20Cr15Si5Al1 High-Entropy Alloy during Stress Corrosion Cracking Phenomenon: Pit Initiation and Growth 应力腐蚀开裂现象中 Fe39Mn20Co20Cr15Si5Al1 高熵合金裂纹成核机制的早期阶段：凹坑萌发和生长

IF 2.7 4区材料科学

Crystals Pub Date : 2024-08-11 DOI: 10.3390/cryst14080719

Pranshul Varshney, Nilesh Kumar

引用次数: 0