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SSRN 2024年

作者： Balica, Naasson Matheus Pereira Almeida, Larissa Solano Rossino, Luciana Sgarbi Pupim, Denise Monção, Renan Matos Costa, Thércio Henrique de Carvalho Santos, Rafaela Luiz Pereira Sousa, Rômulo Ribeiro Magalhães Nunes, Lívio César Cunha Federal University of Piauí Technology Center Graduate Program in Materials Science and Engineering Avenida Universitária s/n Ininga PI Teresina Brazil Federal University of São Carlos Graduate Program in Materials Science SP Sorocaba Brazil University of São Paulo Ribeirão Preto School of Dentistry Avenida do Café SP Ribeirão Preto Brazil Federal University of Rio Grande do Norte Technology Center Department of Mechanical Engineering University Campus Natal RN Lagoa Nova Brazil

Cobalt-chromium and nickel-chromium metal alloys have been widely used as biomaterials in the dental field due to their excellent physical-mechanical properties and biocompatibility, as well as the low cost of the material. However, in unfavorable environments, such as the oral cavity, these dental prostheses composed of these alloys can suffer alterations in their structure where they can undergo rapid changes with the surface corrosion process, which can vary with pH and temperature, typically related to changes in the patient's diet. The aim of this work is to carry out a comparative study between the cathodic cage (CC) and hollow cathode (HC) methods, in which a plasma deposition treatment of titanium nitride (TiN) thin films was carried out on CoCr and NiCr samples, in order to subsequently evaluate their surface characteristics and tribological properties in relation to each method. The samples were characterized using X-ray diffractometry (XRD), scanning electron microscopy (SEM/EDS) and micro abrasive wear tests on each sample from the three groups of alloys mentioned. It was observed that the TiN films provided greater resistance to the wear mechanism of all the samples, where through the characterizations, it can be inferred that the two types of treatments carried out on the samples are suitable for dental applications. © 2024, The Authors. All rights reserved.

关键词： Chromium alloys

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Ab initio study on changing behaviors of lithium-rich layered composite cathode materials

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Electrochimica Acta 2024年 500卷

作者： Chuang, Yu-cheng Tran, Ngoc Thanh Thuy Tsai, Ping-chun Lin, Shih-kang Department of Materials Science and Engineering National Cheng Kung University Tainan70101 Taiwan Research Center National Cheng Kung University Tainan70101 Taiwan Department of Mechanical Engineering National Taiwan University of Science and Technology Taipei10607 Taiwan Program on Smart and Sustainable Manufacturing Academy of Innovative Semiconductor and Sustainable Manufacturing National Cheng Kung University Tainan70101 Taiwan Core Facility Center National Cheng Kung University Tainan70101 Taiwan

The lithium-rich composite-layered oxide, xLi2MnO3•(1-x)LiM'O2, where M’ represents transition metals, is a promising cathode material with excellent capacity at high working voltage for lithium-ion batteries (LIBs). Nevertheless, an unusual charge-discharge feature is observed for this material with sloping and plateau regions during the initial charging. In this work, ab initio calculations based on density functional theory were employed to examine the stability of xLi2MnO3•(1-x)Li(Ni1/3Co1/3Mn1/3)O2 composite-layered cathode materials during the first charging. Optimized atomistic models for different compositions (x = 0.0, 0.3, 0.4, 0.5, 0.7, and 1) unveil a pseudo-rhombohedral or monoclinic-like structure within the solid solution phase, with simulated X-ray diffraction patterns closely matching experimental data. Using these atomistic models, the first charging process of the 0.4Li2MnO3•0.6Li(Ni1/3Co1/3Mn1/3)O2 cathode were investigated. There exists phase transition from a layered to a spinel structure. Additionally, Bader charge analysis reveals intriguing trends during the first delithiation process, where the valence states of Ni and Co gradual increase, while that of Mn almost remains unchanged. Simultaneously, significant oxidation of O is observed. This finding leads to further evaluations on oxygen vacancy formation in comparison to the energy required for delithiation. Defect formation energy calculations demonstrate that the plateau in charging curve is resulted from oxygen vacancy formation during the first charging. By empirical fitting oxygen chemical potential at μO = -1.200 eV, the calculated charging-discharging curves aligned well with experimental data during the first and second charging. Furthermore, the pathways of lithium and oxygen deintercalation are elucidated. This work contributes fundamental understandings on the xLi2MnO3•(1-x)LiM'O2 composite-layered oxides as cathode for LIBs, providing valuable guidance for further developments

关键词： Cathodes

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Linearized frequency domain Landau-Lifshitz-Gilbert equation formulation

arXiv

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arXiv 2022年

作者： Lin, Zhuonan Lomakin, Vitaliy Department of Electrical and Computer Engineering University of California San Diego La Jolla CA92093 United States Center for Memory and Recording Research La Jolla CA92093 United States Materials Science and Engineering Program University of California San Diego La Jolla CA92093 United States

We present a general finite element linearized Landau-Lifshitz-Gilbert equation (LLGE) solver for magnetic systems under weak time-harmonic excitation field. The linearized LLGE is obtained by assuming a small deviation around the equilibrium state of the magnetic system. Inserting such expansion into LLGE and keeping only first order terms gives the linearized LLGE, which gives a frequency domain solution for the complex magnetization amplitudes under an external time-harmonic applied field of a given frequency. We solve the linear system with an iterative solver using generalized minimal residual method. We construct a preconditioner matrix to effectively solve the linear system. The validity, effectiveness, speed, and scalability of the linear solver are demonstrated via numerical examples. Copyright © 2022, The Authors. All rights reserved.

关键词： Linear systems

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Backscattering-free edge states below all bands in two-dimensional auxetic media

arXiv

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arXiv 2023年

作者： Cheng, Wenting Qian, Kai Cheng, Nan Boechler, Nicholas Mao, Xiaoming Sun, Kai Department of Physics University of Michigan Ann ArborMI48109 United States Department of Mechanical and Aerospace Engineering University of California San Diego La Jolla CA92093 United States Program in Materials Science and Engineering University of California San Diego La Jolla CA92093 United States

Unidirectional and backscattering-free propagation of sound waves is of fundamental interest in physics, and highly sought-after in engineering. Current strategies utilize topologically protected chiral edge modes in bandgaps, or complex mechanisms involving active constituents or nonlinearity. Here we propose a new class of passive, linear, one-way edge states based on spin-momentum locking of Rayleigh waves in two-dimensional media in the limit of vanishing bulk modulus, which provides 100% unidirectional and backscattering-free edge propagation at a broad range of frequencies instead of residing in gaps between bulk bands. We further show that such modes are characterized by a new topological winding number that is analogous to discrete angular momentum eigenvalues in quantum mechanics. These passive and backscattering-free edge waves have the potential to enable a new class of phononic devices in the form of lattices or continua that work in previously inaccessible frequency ranges. © 2023, CC BY.

关键词： Backscattering

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Electronic and magnetic properties of perovskite selenite and tellurite compounds: CoSeO3, NiSeO3, CoTeO3, and NiTeO3

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Physical Review B 2020年第4期101卷 045107-045107页

作者： A. Rafi M. Iasir Todd Lombardi Qiangsheng Lu Amir M. Mofrad Mitchel Vaninger Xiaoqian Zhang David J. Singh Nuclear Engineering Program University of Missouri Columbia Missouri 65211 USA Department of Physics and Astronomy University of Missouri Columbia Missouri 65211-7010 USA Department of Biomedical Biological and Chemical Engineering University of Missouri Columbia Missouri 65211 USA Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials Collaborative Innovation Center of Advanced Microstructures School of Electronic Science and Engineering Nanjing University Nanjing 210093 China Department of Chemistry University of Missouri Columbia Missouri 65211 USA

Selenium and tellurium are among the few elements that form ABO3 perovskite structures with a four valent ion in the A site. This leads to highly distorted structures and unusual magnetic behavior. Here we investigate the Co and Ni selenite and tellurite compounds, CoSeO3, CoTeO3, NiSeO3, and NiTeO3, using first principles calculations. We find an interplay of crystal field and Jahn-Teller distortions that underpin the electronic and magnetic properties. While all compounds are predicted to show an insulating G-type antiferromagnetic ground state, there is a considerable difference in the anisotropy of the exchange interactions between the Ni and Co compounds. This is related to the Jahn-Teller distortion. Finally, we observe that these four compounds show characteristics generally associated with Mott insulators, even when described at the level of standard density functional theory. These are then dense bulk insulators that are correctly described as insulators in a standard band structure picture but that satisfy the common experimental criteria to classify them as Mott-type insulators.

关键词： Antiferromagnetism Band gap Exchange interaction Jahn-Teller effect

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Progress in phytoremediation of chromium from the environment

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Chemosphere 2023年 344卷 140307页

作者： Han, Lingzhuo Gu, Haiping Lu, Wenjie Li, Hanyin Peng, Wan-xi Ling Ma, Nyuk Lam, Su Shiung Sonne, Christian College of Forestry Henan Agricultural University Zhengzhou450002 China BIOSES Research Interest Group Faculty of Science & Marine Environment Universiti Malaysia Terengganu 21030 Malaysia Department of Sustainable Engineering Institute of Biotechnology Saveetha School of Engineering SIMATS Chennai602105 India Universiti Malaysia Terengganu Terengganu Kuala Nerus21030 Malaysia Department of Chemical Engineering and Materials Science Yuan Ze University Taoyuan Taiwan Department of Ecoscience Aarhus University Frederiksborgvej 399 Roskilde DK-4000 Denmark Sustainability Cluster School of Engineering University of Petroleum & Energy Studies Uttarakhand Dehradun248007 India

As chromium (Cr) in ecosystems affects human health through food chain exposure, phytoremediation is an environmentally friendly and efficient way to reduce chromium pollution in the environment. Here, we review the mechanism of absorption, translocation, storage, detoxification, and regulation of Cr in plants. The Cr(VI) form is more soluble, mobile, and toxic than Cr(III), reflecting how various valence states of Cr affect environmental risk characteristics, physicochemical properties, toxicity, and plant uptake. Plant root's response to Cr exposure leads to reactive oxygen species (ROS) generation and apoptosis. Cell wall immobilization, vacuole compartmentation, interaction of defense proteins and organic ligand with Cr, and removal of reactive oxygen species by antioxidants continue plant life. In addition, the combined application of microorganisms, genetic engineering, and the addition of organic acids, nanoparticles, fertilization, soil amendments, and other metals could accelerate the phytoremediation process. This review provides efficient methods to investigate and understand the complex changes of Cr metabolism in plants. Preferably, fast-growing, abundantly available biomass species should be modified to mitigate Cr pollution in the environment as these green and efficient remediation technologies are necessary for the protection of soil and water ecology. © 2023

关键词： Detoxification

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Correlative Lattice and Electronic Structural Evolution of Mos2–Ws2 Heterostructure Under High Pressure

SSRN

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SSRN 2024年

作者： Yan, Yalan Feng, Dengman Zhu, Jian Li, Fangfei Institute for Interdisciplinary Biomass Functional Materials Studies Jilin Provincial Key Laboratory of Straw-Based Functional Materials Jilin Engineering Normal University Changchun130052 China Synergetic Extreme Condition High-Pressure Science Center State Key Laboratory of Superhard Materials College of Physics Jilin University Changchun130012 China

Assembling and modifying the vertical heterostructures (HS) based on transition metal dichalcogenides (TMDs) is of great potential in developing novel optical and optoelectronic devices thanks to the presence of unique interlayer excitons possessing long lifetimes in TMDs HS. Here, combining in situ high-pressure Raman and photoluminescence (PL) measurements, and first-principles calculations, both the lattice and electronic structural evolutions of WS2–MoS2 HS were uncovered. First-principles calculation predicted an electronic phase transition from one indirect to another indirect bandgap in WS2–MoS2 HS, evidenced by the appearance of B2g1 mode and the abnormal inflection points of excitons energy vs. pressure after 1.6 GPa. As pressure increases, stacking changes occurred in compressed WS2-MoS2 HS at 6.7 GPa, evidenced by the splitting of E‘-MoS2, A1‘-MoS2 and B1u modes, and the distinct inflection point of Raman mode frequencies and excitons energy vs pressure at 6.7 GPa. In addition, the optical and optoelectronic properties of TMDs HS under high pressure varies dramatically depending on its interlayer coupling at ambient condition, the fabrication and development of pressure-sensitive optical and optoelectronic devices with high efficiency can be realized through the fine regulation of interlayer coupling. © 2024, The Authors. All rights reserved.

关键词： Electronic structure

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Effects of nanoscale embedded Schottky barriers on carrier dynamics in ErAs:GaAs composite systems

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Physical Review B 2015年第13期92卷 134303-134303页

作者： S. N. Gilbert Corder J. K. Kawasaki C. J. Palmstrøm H. T. Krzyżanowska N. H. Tolk Interdisciplinary Materials Science Program Vanderbilt University Nashville Tennessee 37235 USA Materials Department University of California Santa Barbara Santa Barbara California 93106 USA Department of Electrical Engineering University of California Santa Barbara Santa Barbara California 93106 USA Department of Physics and Astronomy Vanderbilt University Nashville Tennessee 37235 USA

Semiconducting GaAs is widely used in microwave and millimeter integrated circuits, infrared LEDs, lasers, and solar cells. Introducing semimetallic ErAs nanoparticles provides a way to controllably tune the optical and electronic properties of GaAs. We show that for high volume fractions (0.5%–10%) of ErAs nanoparticles embedded in GaAs, the relaxation dynamics indicates that ErAs forms discrete states in the GaAs band gap. For specific carrier momentum conditions, the localized Schottky states may be occupied, exhibit carrier trapping, or inject carriers into the GaAs conduction band. Carrier occupation and scattering from the Schottky states has not previously been reported in optical studies of this system. The scattering mechanism is observed to be active above an occupation threshold where the excited carrier density exceeds the trap density. The array of nanoparticle densities and the characterization of the relaxation pathways at multiple carrier excitation energies represents the most complete fundamental investigation of these systems to date.

关键词： SCHOTTKY barrier ERBIUM compounds GALLIUM arsenide semiconductors MICROWAVES NANOCOMPOSITE materials INTEGRATED circuits SOLAR cells ENERGY gaps (Physics)

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Polyether Sulfone Membrane Surface Modification by Electrospun Polysulfone Hybrid Nanocomposite Fibers for Separating Oil/Water Emulsion

SSRN

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SSRN 2022年

作者： Ponnamma, Deepalekshmi Elgawady, Yara Hassan, Mohamed K. Adham, Samer Al-Maas, Mashael Alamgir, Karim Al-Maadeed, Mariam Al Ali Center for Advanced Materials Qatar University P. O. Box 2713 Doha Qatar ConocoPhilips Global Water Sustainability Center Qatar Science and Technology Park Doha Qatar Department of Chemical & Biomolecular Engineering University of Houston S222 Engineering Bldg 1 4726 Calhoun Rd HoustonTX77204 United States Materials Science and Technology Program Qatar University P. O. Box 2713 Doha Qatar

Electrospun fibers of polysulfone (PSf)/iron oxide (FeO)/halloysite nanotubes (HNT) nanocomposite was applied to modify the polyether sulfone (PES) standard membrane support surface for developing highly efficient oil/water emulsion separating membranes. This facile and simple spinning process for shorter periods ensured nanocomposite coatings on the standard PES membranes and allows better oil/water separation process. Moderate hydrophilicity of the membranes results in the higher permeate flux and quicker separation performance. Good regeneration ability and separation performance were achieved for the mechanically stronger membranes as proved from the ultrafiltration and mechanical testing methods. The surface contact angle values are investigated for the hydrophilic nature of the membranes and the under oil angle values show promising results. © 2022, The Authors. All rights reserved.

关键词： Emulsification

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Hybridization of Bogoliubov Quasiparticles between Adjacent CuO2 Layers in the Triple-Layer Cuprate Bi2Sr2Ca2Cu3O10+δ Studied by Angle-Resolved Photoemission Spectroscopy

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Physical Review Letters 2021年第21期127卷 217004-217004页

作者： S. Ideta S. Johnston T. Yoshida K. Tanaka M. Mori H. Anzai A. Ino M. Arita H. Namatame M. Taniguchi S. Ishida K. Takashima K. M. Kojima T. P. Devereaux S. Uchida A. Fujimori Department of Physics University of Tokyo Bunkyo-ku Tokyo 113-0033 Japan UVSOR-III Synchrotron Institute for Molecular Science Okazaki 444-8585 Japan Department of Physics and Astronomy The University of Tennessee Knoxville Tennessee 37996 USA Department of Human and Environmental studies Kyoto University Sakyo-ku Kyoto 606-8501 Japan Advanced Science Research Center Japan Atomic Energy Agency Tokai 319-1195 Japan Graduate School of Engineering Osaka Prefecture University Sakai 599-8531 Japan Graduate School of Science Hiroshima University Higashi-Hiroshima 739-8526 Japan Hiroshima Synchrotron Radiation Center Hiroshima University Higashi-Hiroshima 739-0046 Japan Department of Education and Creation Engineering Kurume Institute of Technology Fukuoka 2286-66 Japan National Institute of Advanced Industrial Science and Technology Tsukuba Ibaraki 305-8568 Japan J-PARC Center and Institute of Materials Structure Science KEK Tsukuba Ibaraki 305-0801 Japan Centre for Molecular and Materials Science TRIUMF 4004 Vancouver Canada Geballe Laboratory for Advanced Materials Stanford University Stanford California 94305 USA Stanford Institute for Materials and Energy Sciences SLAC National Laboratory and Stanford University Menlo Park California 94025 USA Department of Materials Science and Engineering Stanford University Stanford California 94305 USA Department of Applied Physics Waseda University Shinjuku-ku Tokyo 169-8555 Japan

Hybridization of Bogoliubov quasiparticles (BQPs) between the CuO2 layers in the triple-layer cuprate high-temperature superconductor Bi2Sr2Cu2Cu3O10+δ is studied by angle-resolved photoemission spectroscopy (ARPES). In the superconducting state, an anticrossing gap opens between the outer- and inner-BQP bands, which we attribute primarily to interlayer single-particle hopping with possible contributions from interlayer Cooper pairing. We find that the d-wave superconducting gap of both BQP bands smoothly develops with momentum without an abrupt jump in contrast to a previous ARPES study. Hybridization between the BQPs also gradually increases in going from the off nodal to the antinodal region, which is explained by the momentum dependence of the interlayer single-particle hopping. As possible mechanisms for the enhancement of the superconducting transition temperature, the hybridization between the BQPs as well as the combination of phonon modes of the triple CuO2 layers and spin fluctuations represented by a four-well model are discussed.

关键词： Electronic structure Superconducting gap Superconducting order parameter d-wave Cuprates High-temperature superconductors Multilayer thin films Angle-resolved photoemission spectroscopy

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