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Mapping the Non-Monotonic Ageing of Metallic Glasses in the Metastability-Temperature Space

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SSRN

SSRN 2019年

作者： Liu, Chaoyi Yan, Xin Sharma, Pradeep Fan, Yue Department of Mechanical Engineering University of Michigan Ann Arbor United States School of Mechanical Engineering and Automation Beihang University Beijing China Department of Mechanical Engineering University of Houston Department of Physics University of Houston Material Science and Engineering Program University of Houston

Ageing behaviors of metallic glasses are investigated by atomistic modeling in a broad range of processing histories and thermal conditions. By employing an enhanced data-mining analysis, a non-monotonic ageing phenomenon is resolved with high precision. It is observed that there exists a non-linear correlation between the system's metastability and the critical temperature where maximum ageing rate occurs. In further conjunction with the recently developed energy landscape theory to circumvent the time-scale limitations of molecular dynamics, the ageing rate contours over ten orders of magnitude are mapped out in the metastability-temperature space. Such map enables a natural explanation to the experimentally observed shift of exothermic signal, which cannot be provided by existing models. Implications of the present study for understanding the mechanical properties of amorphous alloys are also discussed. © 2019, The Authors. All rights reserved.

关键词： Computation theory

Ionic Functionalization of Multivariate Covalent Organic Frameworks to Achieve an Exceptionally High Iodine-Capture Capacity

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Angewandte Chemie 2021年第41期133卷

作者： Dr. Yaqiang Xie Dr. Tingting Pan Dr. Qiong Lei Dr. Cailing Chen Dr. Xinglong Dong Dr. Youyou Yuan Dr. Jie Shen Dr. Yichen Cai Dr. Chunhui Zhou Prof. Dr. Ingo Pinnau Prof. Dr. Yu Han Advanced Membranes and Porous Materials (AMPM) Center Physical Sciences and Engineering Division King Abdullah University of Science and Technology (KAUST) Thuwal Saudi Arabia Imaging and Characterization Core Lab KAUST Thuwal Saudi Arabia Material Science and Engineering Program Physical Sciences and Engineering Division KAUST Thuwal Saudi Arabia KAUST Catalysis Center Physical Sciences and Engineering Division KAUST Thuwal Saudi Arabia

Adsorption-based iodine (I 2 ) capture has great potential for the treatment of radioactive nuclear waste. In this study, we apply a “multivariate” synthetic strategy to construct ionic covalent organic frameworks (iCOFs) with a large surface area, high pore volume, and abundant binding sites for I 2 capture. The optimized material iCOF-AB-50 exhibits a static I 2 uptake capacity of 10.21 g g −1 at 75 °C and a dynamic uptake capacity of 2.79 g g −1 at ≈400 ppm I 2 and 25 °C, far exceeding the performances of previously reported adsorbents under similar conditions. iCOF-AB-50 also exhibits fast adsorption kinetics, good moisture tolerance, and full reusability. The promoting effect of ionic groups on I 2 adsorption has been elucidated by experimentally identifying the iodine species adsorbed at different sites and calculating their binding energies. This work demonstrates the essential role of balancing the textural properties and binding sites of the adsorbent in achieving a high I 2 capture performance.

关键词： adsorption Coulomb interaction covalent organic frameworks iodine capture

Two-Step Electronic Response to Magnetic Ordering in a van der Waals Ferromagnet

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arXiv 2023年

作者： Wu, Han Zhu, Jian-Xin Chen, Lebing Butcher, Matthew W. Yue, Ziqin Yuan, Dongsheng He, Yu Oh, Ji Seop Huang, Jianwei Wu, Shan Gong, Cheng Guo, Yucheng Mo, Sung-Kwan Denlinger, Jonathan D. Lu, Donghui Hashimoto, Makoto Stone, Matthew B. Kolesnikov, Alexander I. Chi, Songxue Kono, Junichiro Nevidomskyy, Andriy H. Birgeneau, Robert J. Dai, Pengcheng Yi, Ming Department of Physics and Astronomy Rice Center for Quantum Materials Rice University HoustonTX77005 United States Theoretical Division Los Alamos National Laboratory Los AlamosNM87545 United States Center for Integrated Nanotechnologies Los Alamos National Laboratory Los AlamosNM87545 United States Department of Physics University of California at Berkeley BerkeleyCA94720 United States Applied Physics Graduate Program Smalley-Curl Institute Rice University HoustonTX77005 United States Materials Sciences Division Lawrence Berkeley National Laboratory BerkeleyCA94720 United States 1-1 Namiki Ibaraki Tsukuba305-0044 Japan Department of Applied Physics Yale University New HavenCT06511 United States Department of Electrical and Computer Engineering Quantum Technology Center University of Maryland College ParkMD20742 United States Advanced Light Source Lawrence Berkeley National Laboratory BerkeleyCA94720 United States Stanford Synchrotron Radiation Lightsource SLAC National Accelerator Laboratory Menlo ParkCA94025 United States Neutron Scattering Division Oak Ridge National Laboratory Oak RidgeTN37831 United States Department of Electrical and Computer Engineering Rice University HoustonTX77005 United States Smalley-Curl Institute Rice University HoustonTX77005 United States Department of Material Science and NanoEngineering Rice University HoustonTX77005 United States Department of Materials Science and Engineering University of California Berkeley United States

The two-dimensional (2D) material Cr2Ge2Te6 is a member of the class of insulating van der Waals magnets. Here, using high resolution angle-resolved photoemission spectroscopy in a detailed temperature dependence study, we identify a clear response of the electronic structure to a dimensional crossover in the form of two distinct temperature scales marking onsets of modifications in the electronic structure. Specifically, we observe Te p-orbital-dominated bands to undergo changes at the Curie transition temperature TC while the Cr d-orbital-dominated bands begin evolving at a higher temperature scale. Combined with neutron scattering, density functional theory calculations, and Monte Carlo simulations, we find that the electronic system can be consistently understood to respond sequentially to the distinct temperatures at which in-plane and out-of-plane spin correlations exceed a characteristic length scale. Our findings reveal the sensitivity of the orbital-selective electronic structure for probing the dynamical evolution of local moment correlations in vdW insulating magnets. © 2023, CC BY.

关键词： Electronic structure

Spray-drying synthesis of Bi 2 O 3 /BiVO 4 composites with thin carbon coating for high performance photocatalytic degradation of organic pollutant

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Journal of the Taiwan Institute of Chemical Engineers 2025年

作者： Kuen-Chan Lee Shih-Chieh Hsu Jen-Hsien Huang Tzu-Hsien Hsieh Wei Kong Pang Hsiang-Ting Lan Er-Chieh Cho Huei Chu Weng Ting-Yu Liu Department of Science Education National Taipei University of Education No. 134 Sec. 2 Heping E. Road Da-an District Taipei City 106 Taiwan PhD Program in Medical Neuroscience College of Medical Science and Technology Taipei Medical University 250 Wuxing Street Taipei City 110 Taiwan Department of Chemical and Materials Engineering Tamkang University No. 151 Yingzhuan Road Tamsui District New Taipei City 25137 Taiwan Department of Green Material Technology Green Technology Research Institute CPC Corporation No.2 Zuonan Rd. Nanzi District Kaohsiung City 81126 Taiwan Faculty of Engineering Institute for Superconducting & Electronic Materials University of Wollongong Wollongong NSW Australia Department of Materials Engineering Ming Chi University of Technology New Taipei City 243303 Taiwan Department of Clinical Pharmacy School of Pharmacy College of Pharmacy Taipei Medical University 250 Wuxing Street Taipei City 110 Taiwan Department of Mechanical Engineering Chung Yuan Christian University No. 200 Chungpei Road Chungli District Taoyuan City 32023 Taiwan Department of Chemical Engineering and Materials Science Yuan Ze University Taoyuan City 32003 Taiwan College of Engineering & Center for Sustainability and Energy Technologies Chang Gung University Taoyuan 33302 Taiwan

Background To achieve efficient solar-to-chemical energy conversion in photocatalysis, it is crucial to develop visible-light-driven catalysts with excellent charge transport properties and superior activity. Methods Here, p-n heterostructured Bi 2 O 3 /BiVO 4 (BO/BVO) composites were synthesized via a spray-drying method, incorporating synergistic effects of oxygen vacancies and asphaltene-derived carbon coating. Significant findings The built-in electric field at the p −type BO and n-type BVO interface, combined with the electron sink effect of the coated graphitic carbon layer, enhances charge transfer while suppressing charge recombination. As a result, the carbon coated BO/BVO (C-BO/BVO) heterojunction reveals markedly improved efficiency for photodegradation of methylene blue (MB) in comparison with pure BO and BVO. Under visible light irradiation, the C-BO/BVO composite achieves an MB decomposition efficiency of 92.1 %, which is approximately 1.78, 2.23, and 2.98 times higher than that of BO/BVO, pure BVO, and pure BO, respectively. As a result, the C-BO/BVO composites exhibit superior degradation performance for MB and tetracycline (TC), achieving high rate constants of 6.51 × 10 −2 min −1 and 7.55 × 10 −3 min −1 , respectively. The C-BO/BVO photocatalysts also exhibit exceptional antibacterial activity against Escherichia coli ( E. coli ). Additionally, their biocompatibility has been assessed using an in vivo zebrafish embryo model, highlighting their potential for future biomedical applications.

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Shear-induced polydomain structures of nematic lyotropic chromonic liquid crystal disodium cromoglycate

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arXiv 2020年

作者： Baza, Hend Turiv, Taras Li, Bing-Xiang Li, Ruipeng Yavitt, Benjamin M. Fukuto, Masafumi Lavrentovich, Oleg D. Department of Physics Kent State University OH United States Advanced Materials and Liquid Crystal Institute Kent State University OH United States Materials Science Graduate Program Kent State University OH United States National Synchrotron Light Source II Brookhaven National Laboratory UptonNY United States Department of Material Science and Chemical Engineering Stony Brook University Stony BrookNY United States

Lyotropic chromonic liquid crystals (LCLCs) represent aqueous dispersions of organic disk-like molecules that form cylindrical aggregates. Despite the growing interest in these materials, their flow behavior is poorly understood. Here, we explore the effect of shear on dynamic structures of the nematic LCLC, formed by 14wt% water dispersion of disodium cromoglycate (DSCG). We employ in-situ polarizing optical microscopy (POM) and small-angle and wide-angle X-ray scattering (SAXS/WAXS) to obtain independent and complementary information on the director structures over a wide range of shear rates. The DSCG nematic shows a shear-thinning behavior with two shear-thinning regions (Region I at γ −1 and Region III at γ > 10 s−1) separated by a pseudo-Newtonian Region II (1 s−1 −1). The material is of a tumbling type. In Region I, γ −1, the director realigns along the vorticity axis. An increase of γ above 1 s-1 triggers nucleation of disclination loops. The disclinations introduce patches of the director that deviates from the vorticity direction and form a polydomain texture. Extension of the domains along the flow and along the vorticity direction decreases with the increase of the shear rate to 10 s−1. Above 10 s−1, the domains begin to elongate along the flow. At γ > 100 s−1, the texture evolves into periodic stripes in which the director is predominantly along the flow with left and right tilts. The period of stripes decreases with an increase of γ. The shear-induced transformations are explained by the balance of the elastic and viscous energies. In particular, nucleation of disclinations is associated with an increase of the elastic energy at the walls separating nonsingular domains with different director tilts. The uncovered shear-induced structural effects would be of importance in the further development of LCLC applications. Copyright © 2020, The Authors. All rights reserved.

关键词： Shear deformation

Chiral Phonons with Giant Magnetic Moments in a Topological Crystalline Insulator

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arXiv 2022年

作者： Hernandez, Felix G.G. Baydin, Andrey Chaudhary, Swati Tay, Fuyang Katayama, Ikufumi Takeda, Jun Nojiri, Hiroyuki Okazaki, Anderson K. Rappl, Paulo H.O. Abramof, Eduardo Rodriguez-Vega, Martin Fiete, Gregory A. Kono, Junichiro Instituto de Física Universidade de São Paulo SP São Paulo05508-090 Brazil Department of Electrical and Computer Engineering Rice University HoustonTX77005 United States Smalley-Curl Institute Rice University HoustonTX77005 United States Department of Physics The University of Texas at Austin AustinTX78712 United States Department of Physics Northeastern University BostonMA02115 United States Department of Physics Massachusetts Institute of Technology CambridgeMA02139 United States Applied Physics Graduate Program Smalley-Curl Institute Rice University HoustonTX77005 United States Department of Physics Graduate School of Engineering Science Yokohama National University Yokohama240-8501 Japan Institute for Materials Research Tohoku University Sendai980-8577 Japan Instituto Nacional de Pesquisas Espaciais SP São José dos Campos12201-970 Brazil Department of Physics and Astronomy Rice University HoustonTX77005 United States Department of Material Science and NanoEngineering Rice University HoustonTX77005 United States

We have studied the magnetic response of transverse optical phonons in Pb1−xSnxTe films. Polarization-dependent terahertz magnetospectroscopy measurements revealed Zeeman splittings and diamagnetic shifts, demonstrating that these phonon modes become chiral in magnetic fields. Films in the topological crystalline insulator phase (x > 0.32) exhibited magnetic moment values that are larger than those for topologically trivial films (x Copyright © 2022, The Authors. All rights reserved.

关键词： Phonons

Robust Coupling between Structural and Electronic Transitions in a Mott material

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Physical Review Letters 2019年第5期122卷 057601-057601页

作者： Yoav Kalcheim Nikita Butakov Nicolas M. Vargas Min-Han Lee Javier del Valle Juan Trastoy Pavel Salev Jon Schuller Ivan K. Schuller Department of Physics and Center for Advanced Nanoscience University of California San Diego La Jolla California 92093 USA Department of Electrical and Computer Engineering University of California Santa Barbara Santa Barbara California 93106 USA Material Science and Engineering Program University of California San Diego La Jolla California 92093 USA

The interdependences of different phase transitions in Mott materials are fundamental to the understanding of the mechanisms behind them. One of the most important relations is between the ubiquitous structural and electronic transitions. Using IR spectroscopy, optical reflectivity, and x-ray diffraction, we show that the metal-insulator transition is coupled to the structural phase transition in V2O3 films. This coupling persists even in films with widely varying transition temperatures and strains. Our findings are in contrast to recent experimental findings and theoretical predictions. Using V2O3 as a model system, we discuss the pitfalls in measurements of the electronic and structural states of Mott materials in general, calling for a critical examination of previous work in this field. Our findings also have important implications for the performance of Mott materials in next-generation neuromorphic computing technology.

关键词： Crystal growth Crystal orientation Crystal structure Crystal symmetry Crystallization Electronic structure Peierls transition Phase transitions Spin state transition Strain Antiferromagnets Mott insulators Stimuli-responsive materials Strongly correlated systems Thin films Cavity resonators Crystallography Fourier transform infrared spectroscopy Resistivity measurements Scanning techniques Sputtering Strain engineering X-ray diffraction

Solvation Rule for Solid-Electrolyte Interphase Enabler in Lithium-Metal Batteries

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Angewandte Chemie 2020年第41期132卷

作者： Su C.-C. He M. Shi J. Amine R. Zhang J. Amine K. Chemical Sciences and Engineering Division Argonne National Laboratory 9700 S. Cass Avenue Lemont IL 60439 United States Department of Chemical and Environmental Engineering University of California-Riverside Riverside CA 92521 United States Materials Science Division Argonne National Laboratory 9700 S. Cass Avenue Lemont IL 60439 United States Program of Materials Science and Engineering University of California-Riverside Riverside CA 92521 United States Material Science and Engineering Stanford University Stanford CA 94305 United States IRMC Imam Abdulrahman Bin Faisal University (IAU) Dammam 34212 Saudi Arabia

Despite the exceptionally high energy density of lithium metal anodes, the practical application of lithium-metal batteries (LMBs) is still impeded by the instability of the interphase between the lithium metal and the electrolyte. To formulate a functional electrolyte system that can stabilize the lithium-metal anode, the solvation behavior of the solvent molecules must be understood because the electrochemical properties of a solvent can be heavily influenced by its solvation status. We unambiguously demonstrated the solvation rule for the solid-electrolyte interphase (SEI) enabler in an electrolyte system. In this study, fluoroethylene carbonate was used as the SEI enabler due to its ability to form a robust SEI on the lithium metal surface, allowing relatively stable LMB cycling. The results revealed that the solvation number of fluoroethylene carbonate must be ≥1 to ensure the formation of a stable SEI in which the sacrificial reduction of the SEI enabler subsequently leads to the stable cycling of LMBs. © 2020 Wiley-VCH GmbH

关键词： anode stabilization electrolyte solvation lithium-metal batteries solid-electrolyte interphase solvation numbers

Discovery of ionic impact ionization (I3) in perovskites triggered by a single photon

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arXiv 2019年

作者： Xu, Zihan Yu, Yugang Niaz, Iftikhar Ahmad Chen, Yimu Arya, Shaurya Lei, Yusheng Miah, Mohammad Abu Raihan Zhou, Jiayun Zhang, Alex Ce Yan, Lujiang Xu, Sheng Nomura, Kenji Lo, Yu-Hwa Department of NanoEngineering University of California San DiegoCA United States Material Science and Engineering Program University of California San DiegoCA United States Department of Electrical and Computer Engineering University of California San DiegoCA United States

Organic-inorganic metal halide perovskite devices have generated significant interest for LED, photodetector, and solar cell applications due to their attractive optoelectronic properties and substrate-choice flexibility1-4. These devices exhibit slow time-scale response, which have been explained by point defect migration5-6. In this work, we report the discovery of a room temperature intrinsic amplification process in methylammonium lead iodide perovskite (MAPbI3) that can be triggered by few photons, down to a single photon. The electrical properties of the material, by way of photoresponse, are modified by an input energy as small as 0.19 attojoules, the energy of a single photon. These observations cannot be explained by photo-excited electronic band-to-band transitions or prevailing model of photoexcited point defect migration since none of the above can explain the observed macroscopic property change by absorption of single or few photons. The results suggest the existence of an avalanche-like collective motion of iodides and their accumulation near the anode, which we will call "ionic impact ionization" (I3 mechanism). The proposed I3 process is the ionic analog of the electronic impact ionization, and has been considered impossible before because conventionally it takes far more energy to move ions out of their equilibrium position than electrons. We have performed first principle calculations to show that in MAPbI3 the activation energy for the I3 mechanism is appreciably lower than the literature value of the activation energy for the electronic impact ionization. The discovery of I3 process in perovskite material opens up possibilities for new classes of devices for photonic and electronic applications. Copyright © 2019, The Authors. All rights reserved.

关键词： Iodine compounds