Crystals最新文献

{"title":"General Trends in the Compression of Glasses and Liquids","authors":"Oliver Tschauner","doi":"10.3390/cryst14090815","DOIUrl":"https://doi.org/10.3390/cryst14090815","url":null,"abstract":"The present work relates the isothermal volumes of silicate glasses and melts to the combined ionic volumes of their chemical constituents. The relation is an extension of a relation that has already been established for crystalline oxides, silicates, alumosilicates, and other materials that have O2− as a constituent anion. The relation provides constraints on bond coordination, indicates pressure-induced changes in coordination in melts and glasses and interatomic distances, and quantifies the extent of transitory regions in pressure-induced coordination changes.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"203 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257053","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}

{"title":"Impact of Mg on the Feeding Ability of Cast Al–Si7–Mg(0_0.2_0.4_0.6) Alloys","authors":"Mile Djurdjevic, Srecko Manasijevic, Aleksandra Patarić, Srecko Stopic, Marija Mihailović","doi":"10.3390/cryst14090816","DOIUrl":"https://doi.org/10.3390/cryst14090816","url":null,"abstract":"The demand for high-performance Al–Si casting alloys is driven by their mechanical properties, making them popular in automotive, aerospace, and engineering industries. These alloys, especially hypoeutectic Al–Si–Mg, offer benefits like high fluidity, low thermal expansion, and good corrosion resistance. Silicon and magnesium primarily define their microstructure and mechanical properties. Silicon enhances fluidity, while magnesium improves strength and fatigue resistance. However, challenges like shrinkage porosity persist during solidification. Understanding solidification feeding regions is crucial, influenced by factors such as chemical composition, solidification characteristics, and casting design. This study investigates magnesium’s influence on feeding ability in hypoeutectic Al–Si7–Mg alloys through experimental tests. Increasing magnesium content from 0% to 0.6% affects the interdendritic and burst feeding regions. This could impact shrinkage porosity formation. The “Sand Hourglass” test results indicate a rise in porosity levels with higher magnesium content, which is linked to the narrowing of interdendritic channels and the formation of magnesium-rich intermetallic compounds. These changes hinder the liquid metal flow, worsening shrinkage porosity. Therefore, magnesium’s role in expanding the interdendritic region is a key factor in developing porosity in cast hypoeutectic Al–Si7–Mg alloys. This study highlights that porosity levels increase from 0% in magnesium-free Al–Si7 to 0.84% in Al–Si7–Mg0.6, underscoring magnesium’s significant impact on the occurrence of porosity in these alloys.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"119 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257052","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}

{"title":"The Counterion (SO42− and NO3−) Effect on Crystallographic, Quantum-Chemical, Protein-, and DNA-Binding Properties of Two Novel Copper(II)–Pyridoxal-Aminoguanidine Complexes","authors":"Violeta Jevtovic, Luka Golubović, Odeh A. O. Alshammari, Munirah Sulaiman Alhar, Tahani Y. A. Alanazi, Violeta Rakic, Rakesh Ganguly, Jasmina Dimitrić Marković, Aleksandra Rakić, Dušan Dimić","doi":"10.3390/cryst14090814","DOIUrl":"https://doi.org/10.3390/cryst14090814","url":null,"abstract":"New Cu(II) complexes with pyridoxal-aminoguanidine (PLAG) ligands and different counterions (SO42− and NO3−) were prepared and their crystal structures were solved by the X-ray crystallography. The geometries of the obtained complexes significantly depended on the counterions, leading to the square-pyramidal structure of [Cu(PLAG)NO3H2O]NO3 (complex 1) and square-planar structure of [Cu(PLAG)H2O]SO4 (complex 2). The intermolecular interactions were examined using the Hirshfeld surface analysis. The theoretical structures of these complexes were obtained by optimization at the B3LYP/6-311++G(d,p)(H,C,N,O,S)/LanL2DZ(Cu) level of theory. The Quantum Theory of Atoms in Molecules (QTAIM) was applied to assess the strength and type of the intramolecular interactions and the overall stability of the structures. The interactions between the complexes and transport proteins (human serum albumin (HSA)) and calf thymus DNA (CT-DNA) were examined by spectrofluorometric/spectrophotometric titration and molecular docking. The binding mechanism to DNA was assessed by potassium iodide quenching experiments. The importance of counterions for binding was shown by comparing the experimental and theoretical results and the examination of binding at the molecular level.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"21 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142269156","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}

{"title":"Surface Electronic Structure of Cr Doped Bi2Se3 Single Crystals","authors":"Turgut Yilmaz, Xiao Tong, Zhongwei Dai, Jerzy T. Sadowski, Genda Gu, Kenya Shimada, Sooyeon Hwang, Kim Kisslinger, Elio Vescovo, Boris Sinkovic","doi":"10.3390/cryst14090812","DOIUrl":"https://doi.org/10.3390/cryst14090812","url":null,"abstract":"Here, by using angle-resolved photoemission spectroscopy, we showed that Bi2−xCrxSe3 single crystals have a distinctly well-defined band structure with a large bulk band gap and undistorted topological surface states. These spectral features are unlike their thin film forms in which a large nonmagnetic gap with a distorted band structure was reported. We further provide laser-based high resolution photoemission data which reveal a Dirac point gap even in the pristine sample. The gap becomes more pronounced with Cr doping into the bulk of Bi2Se3. These observations show that the Dirac point can be modified by the magnetic impurities as well as the light source.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"43 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257056","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}

{"title":"The Enamelled Tiles of Olite’s Castle (Spain): Characterization, Provenance, and Manufacture Technology","authors":"Iván Ruiz-Ardanaz, Esther Lasheras, Adrián Durán","doi":"10.3390/cryst14090813","DOIUrl":"https://doi.org/10.3390/cryst14090813","url":null,"abstract":"The objective of this study was to determine the authorship, provenance, and technology of the mudejar enamelled tiles from the Olite Castle (northern Spain, 14th century). According to previous knowledge, Olite’s enamelled tiles had been manufactured in Manises (Valencia, Spain). The analysis of ceramic pastes revealed the existence of two different chemical compositions, suggesting the use of two different clay sources, probably one from the Tudela area, and another from the Tafalla–Olite area. Those probably made in the Tudela area stood out with a higher diopside (CaMgSi2O6) content. Those probably made in the Tafalla–Olite area stood out for their calcium-bearing minerals, such as calcite (CaCO3) or gehlenite (Ca2Al(AlSi)O7). On this basis, production in Manises has been ruled out. However, it is highly probable that the artisans of Manises would have led the production from Tudela. The study of the firing temperatures and composition of the enamels indicated that the production methods and materials used in Tafalla–Olite (800–850 °C) and Tudela (higher than 900 °C) were different, reflecting the influence of local and Manises artisans, respectively. In Olite tiles, enamel was applied following recipes from the 14th and 15th centuries.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"1 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257057","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}

{"title":"The Effects of Laser Parameters on the Wear Resistance of a Cu/BN Remelted Layer","authors":"Hengzheng Li, Shuai Chen, Yang Chen, Yan Liu, Zichen Tao, Yinghe Qin, Conghu Liu","doi":"10.3390/cryst14090809","DOIUrl":"https://doi.org/10.3390/cryst14090809","url":null,"abstract":"In order to improve the wear resistance of copper and enhance the surface properties of copper parts, this article uses BN nanoparticles as a reinforcing phase and the laser remelting method to prepare a Cu/BN remelted layer on the copper surface. The surface morphology, crystal structure, microhardness, and wear resistance of the samples were tested and characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), a microhardness tester, and a friction and wear tester. The effects of laser frequency, pulse width, and energy density on the surface morphology and wear resistance of the samples were analyzed and studied, and the effects of the laser parameters on the properties of the Cu/BN remelted layer were discussed. The research results indicate that laser frequency, pulse width, and energy density have a direct impact on the surface morphology and properties of the Cu/BN remelted layer, but the impact mechanism by the above parameters on the remelted layer is different. The effects of laser frequency on the remelted layer are caused by changes in the overlap mode of the remelting points, while laser pulse width and energy density are achieved through changes in remelting intensity. When the laser frequency is 10 Hz, the pulse width is 10 ms, and the energy density is 165.8 J/mm2, the Cu/BN remelted layer has better surface properties.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"12 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202492","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}

{"title":"Pulsed Laser Polishing of Zirconia Ceramic Microcrack Generation Mechanism and Size Characterization Study","authors":"Zhanwang Zhou, Zhenyu Zhao, Jin He, Ruikang Shi","doi":"10.3390/cryst14090810","DOIUrl":"https://doi.org/10.3390/cryst14090810","url":null,"abstract":"In order to study the mechanism of microcrack generation in the process of pulsed laser polishing of zirconia ceramics and the influence of laser polishing process parameters on the surface temperature and surface stress, this paper establishes a finite element computational model of pulsed laser polishing of zirconia ceramics based on the COMSOL Multiphysics multi-physics field simulation software. Firstly, in the process of establishing the finite element model, the temperature field and stress field coupling is used to analyze the temperature field and stress field changes during the laser polishing process, which reveals the microcrack generation mechanism and size characteristics of zirconia ceramics in the process of pulsed laser polishing. Secondly, through parameterized scanning, the variation rules of surface temperature and surface stress were studied under different process parameters of laser power, scanning speed, pulse frequency and pulse width. Finally, the validity of the finite element calculation model is verified by the pulsed laser polishing zirconia ceramics experiment. The results show that, in a certain energy range, the high-energy laser beam can effectively reduce the surface roughness of the material, and with the increase in the time of laser action on the surface layer of the material, it will cause the temperature and thermal stress of the surface layer of the material to continue to accumulate, and when the stress value exceeds the yield limit of the material, cracks will form in the surface layer of the material; because the laser power, scanning speed, pulse frequency and pulse width are used to affect the laser energy density, and then, the pulse width will be affected by the process parameters of the laser energy density, and thus the surface temperature and thermal stress of the surface layer of the material. Because the laser power, scanning speed, pulse frequency and pulse width all affect the thermal stress on the material surface by influencing the laser energy density acting on the material surface, the laser energy density is the main influencing factor of the dimensional characteristics of the microcracks. In addition, the microcrack width and depth will increase when the laser energy density acting on the material surface layer increases.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"4 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202496","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}

{"title":"Review of the Properties of GaN, InN, and Their Alloys Obtained in Cubic Phase on MgO Substrates by Plasma-Enhanced Molecular Beam Epitaxy","authors":"Edgar López Luna, Miguel Ángel Vidal","doi":"10.3390/cryst14090801","DOIUrl":"https://doi.org/10.3390/cryst14090801","url":null,"abstract":"Gallium nitride (GaN) semiconductors and their broadband InGaN alloys in their hexagonal phase have been extensively studied over the past 30 years and have allowed the development of blue-ray lasers, which are essential disruptive developments. In addition to high-efficiency white light-emitting diodes, which have revolutionized lighting technologies and generated a great industry around these semiconductors, several transistors have been developed that take advantage of the characteristics of these semiconductors. These include power transistors for high-frequency applications and high-power transistors for power electronics, among other devices, which have far superior achievements. However, less effort has been devoted to studying GaN and InGaN alloys grown in the cubic phase. The metastable or cubic phase of III-N alloys has superior characteristics compared to the hexagonal phase, mainly because of the excellent symmetry. It can be used to improve lighting technologies and develop other devices. Indium gallium nitride, InxGa1−xN alloy, has a variable band interval of 0.7 to 3.4 eV that covers almost the entire solar spectrum, making it a suitable material for increasing the efficiencies of photovoltaic devices. In this study, we successfully synthesized high-quality cubic InGaN films on MgO (100) substrates using plasma-assisted molecular beam epitaxy (PAMBE), demonstrating tunable emissions across the visible spectrum by varying the indium concentration. We significantly reduced the defect density and enhanced the crystalline quality by using an intermediate cubic GaN buffer layer. We not only developed a heterostructure with four GaN/InGaN/GaN quantum wells, achieving violet, blue, yellow, and red emissions, but also highlighted the immense potential of cubic InGaN films for high-efficiency light-emitting diodes and photovoltaic devices. Achieving better p-type doping levels is crucial for realizing diodes with excellent performance, and our findings will pave the way for this advancement.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"54 35 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202493","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}

{"title":"Germanium Single Crystals for Photonics","authors":"Grigory Kropotov, Vladimir Rogalin, Ivan Kaplunov","doi":"10.3390/cryst14090796","DOIUrl":"https://doi.org/10.3390/cryst14090796","url":null,"abstract":"Germanium (Ge) is a system-forming material of IR photonics for the atmospheric transparency window of 8–14 µm. For optics of the 3–5 µm range, more widespread silicon (Si), which has phonon absorption bands in the long-wave region, is predominantly used. A technology for growing Ge single crystals has been developed, allowing the production of precision optical parts up to 500 mm in diameter. Ge is used primarily for the production of transparent optical parts for thermal imaging devices in the 8–14 µm range. In addition, germanium components are widely used in a large number of optical devices where such properties as mechanical strength, good thermal properties, and climatic resistance are required. A very important area of application of germanium is nonlinear optics, primarily acousto-optics. The influence of doping impurities and temperature on the absorption of IR radiation in germanium is considered in detail. The properties of germanium photodetectors are reported, primarily on the effect of photon drag of holes. Optical properties in the THz range are considered. The features of optical properties for all five stable isotopes of germanium are studied. The isotopic shift of absorption bands in the IR region, caused by phonon phenomena, which was discovered by the authors for the first time, is considered.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"20 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202499","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}

{"title":"Prediction of Intriguing Valley Properties in Two-Dimensional Hf2TeIX (X = I, Br) Monolayers","authors":"Kaiyuan He, Peiji Wang","doi":"10.3390/cryst14090794","DOIUrl":"https://doi.org/10.3390/cryst14090794","url":null,"abstract":"The valley degree of freedom, as a new information carrier, is important for basic physical research and the development of advanced devices. Herein, using first-principle calculations, we predict that two-dimensional Hf2TeIX (X = I, Br) monolayers harbor intriguing valley properties. Without considering spin–orbit coupling (SOC), the Hf2TeI2 monolayer has a semi-metallic nature, with Dirac cones located at the high-symmetry point K, and feature, with considerable Fermi velocity. When the SOC is taken into account, a band gap opening of 271 meV can be observed at the Dirac cones. More interestingly, the Hf2TeIBr monolayer exhibits intrinsic spatial inversion symmetry breaking, which leads to the emergence of valley-contrasting physics under SOC. This is demonstrated by the presence of spin–valley splitting and opposite Berry curvature at adjacent K points. Besides, the spin–valley splitting, the band gap and magnitude of the Berry curvature of the Hf2TeIBr monolayer can be effectively tuned by strain engineering. These findings contribute significantly to the design of valleytronic devices and extend opportunities for exploring two-dimensional valley materials.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"28 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202498","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}