检索结果-内蒙古大学图书馆

Nanoscale ferroelectric domain switching and thickness scaling impact in undoped hafnium-oxide ferroelectric devices

学校读者我要写书评

暂无评论

Thin Solid Films 2024年 799卷

作者： Fan, Chia-Chi Chen, Hsuan-Han Liao, Ruo-Yin Chou, Wu-Ching Huang, Ching-Chien Hsu, Hsiao-Hsuan Han, Su-Ting Cheng, Chun-Hu Department of Electronics Engineering National Yang Ming Chiao Tung University Hsinchu30010 Taiwan Department of Electro-Physics National Yang Ming Chiao Tung University Hsinchu30010 Taiwan Department of Mechanical Engineering National Kaohsiung University of Science and Technology Kaohsiung80778 Taiwan Institute of Materials Science and Engineering National Taipei University of Technology Taipei10608 Taiwan Department of Applied Biology and Chemical Technology The Hong Kong Polytechnic University Hunghom Hong Kong Department of Mechatronic Engineering National Taiwan Normal University Taipei10610 Taiwan

In this work, we investigated the polarization characteristics of nanoscale undoped hafnium oxide (HfO2) ferroelectric film. The nanoscale domain switching behavior of undoped HfO2 is mainly dominated by mixed ferroelectric/nonferroelectric crystalline phases and interface domain pinning by oxygen vacancies or defect traps. Our experimental results confirm that these issues can be improved by film thickness scaling and well-controlled mechanical stress. We demonstrated a 4-nm-thick undoped HfO2 negative capacitance thin film transistor (NCFET) with an energy-efficient switch characteristic of a low overdrive voltage of -0.6 V, a steep subthreshold swing of sub-60 mV/dec and a uniform hysteresis distribution of sub-60 mV. © 2024 Elsevier B.V.

关键词： Hafnium oxides

Retraction Note: Enhanced optical and thermal conductivity properties of barium titanate ceramic via strontium doping for thermo-optical applications

学校读者我要写书评

暂无评论

Optical and Quantum Electronics 2024年第1期57卷 1-2页

作者： Tihtih, Mohammed Eldin F. M. Ibrahim, Jamal A. Basyooni, Mohamed En‑nadir, Redouane Belaid, Walid M. Abdelfattah, Mohamed Hussainova, Irina Pszota, Gábor Kocserha, István Institute of Ceramics and Polymer Engineering University of Miskolc Miskolc Hungary Department of Nanotechnology and Advanced Materials Graduate School of Applied and Natural Science Selçuk University Konya Turkey Science and Technology Research and Application Center (BITAM) Necmettin Erbakan University Konya Turkey LPS Faculty of Sciences Sidi Mohamed Ben Abdellah University Fez Morocco Department of Physics Faculty of Science Selçuk University Konya Turkey Department of Mechanical and Industrial Engineering Tallinn University of Technology Tallinn Estonia Institute of Physics and Electrical Engineering University of Miskolc Miskolc Hungary

Characterizing the mechanical response of metallic glasses to uniaxial tension using a spring network model

学校读者我要写书评

暂无评论

arXiv 2023年

作者： Nawano, Aya Schroers, Jan Shattuck, Mark D. O’Hern, Corey S. Department of Mechanical Engineering and Materials Science Yale University New HavenCT06520 United States Benjamin Levich Institute and Physics Department The City College of New York New YorkNY10031 United States Department of Physics Yale University New HavenCT06520 United States Department of Applied Physics Yale University New HavenCT06520 United States Graduate Program in Computational Biology and Bioinformatics Yale University New HavenCT06520 United States

Metallic glasses are frequently used as structural materials. Therefore, it is important to develop methods to predict their mechanical response as a function of the microstructure prior to loading. We develop a novel coarse-grained spring network model, which describes the mechanical response of metallic glasses using an equivalent series network of springs, which can break and re-form to mimic atomic rearrangements during deformation. To validate the spring network model, we perform numerical simulations of quasistatic, uniaxial tensile deformation of Lennard-Jones and embedded atom method (EAM) potentials for Cu50Zr50 metallic glasses in the absence of large-scale shear band formation. We consider samples prepared using a wide range of cooling rates and with different amounts of crystalline order. We show that both the Lennard-Jones and EAM models possess qualitatively similar stress σ versus strain γ curves. By specifying five parameters in the spring network model (ultimate strength, strain at ultimate strength, slopes of σ(γ) at γ = 0 and at large strain, and strain at fracture where σ = 0), we can accurately describe the form of the stress-strain curves during uniaxial tension for the computational studies of Cu50Zr50, as well as recent experimental studies of several Zr-based metallic glasses. For the computational studies of Cu50Zr50, we find that the yield strain distribution is shifted to larger strains for slowly cooled glasses compared to rapidly cooled glasses. In addition, the average number of new springs and their rate of formation decreases with decreasing cooling rate. These effects offset each other at large strains, causing the stress-strain curve to become independent of the sample preparation protocol in this regime. In future studies, we will extract the parameters that define the spring network model directly from atomic rearrangements that occur during uniaxial deformation. © 2023, CC BY-NC-ND.

关键词： Metallic glass

Magnetic Exciton-Polariton with Strongly Coupled Atomic and Photonic Anisotropies

学校读者我要写书评

暂无评论

arXiv 2023年

作者： Li, Qiuyang Xie, Xin Alfrey, Adam Beach, Christiano W. McLellan, Nicholas Lu, Yang Hu, Jiaqi Liu, Wenhao Dhale, Nikhil Lv, Bing Zhao, Liuyan Sun, Kai Deng, Hui Department of Physics University of Michigan Ann ArborMI48109 United States Applied Physics Program University of Michigan Ann ArborMI48109 United States Department of Electrical Engineering and Computer Science University of Michigan Ann ArborMI48109 United States Department of Physics University of Texas at Dallas RichardsonTX75080 United States

Anisotropy plays a key role in science and engineering. However, the interplay between the material and engineered photonic anisotropies has hardly been explored due to the vastly different length scales. Here we demonstrate a matter-light hybrid system, exciton-polaritons in a 2D antiferromagnet, CrSBr, coupled with an anisotropic photonic crystal (PC) cavity, where the spin, atomic lattice, and photonic lattices anisotropies are strongly correlated, giving rise to unusual properties of the hybrid system and new possibilities of tuning. We show exceptionally strong coupling between engineered anisotropic optical modes and anisotropic excitons in CrSBr, which is stable against excitation densities a few orders of magnitude higher than polaritons in isotropic materials. Moreover, the polaritons feature a highly anisotropic polarization tunable by tens of degrees by controlling the matter-light coupling via, for instance, spatial alignment between the material and photonic lattices, magnetic field, temperature, cavity detuning and cavity quality-factors. The demonstrated system provides a prototype where atomic- and photonic-scale orders strongly couple, opening opportunities of photonic engineering of quantum materials and novel photonic devices, such as compact, on-chip polarized light source and polariton laser. © 2023, CC BY-NC-ND.

关键词： Anisotropy

Striation lines in intermittent fatigue crack growth in an Al alloy

学校读者我要写书评

暂无评论

Physical Review Materials 2023年第5期7卷 053602-053602页

作者： Anniina Kinnunen Ivan V. Lomakin Tero Mäkinen Kim Widell Juha Koivisto Mikko J. Alava Department of Applied Physics Aalto University P.O. Box 11100 00076 Aalto Espoo Finland NOMATEN Centre of Excellence National Centre for Nuclear Research A. Soltana 7 05-400 Otwock-Świerk Poland Department of Mechanical Engineering Aalto University P.O. Box 11000 00076 Aalto Espoo Finland

Fatigue failure of crystalline materials is a difficult problem in science and engineering, and recent results have shown that fatigue crack growth can occur in intermittent jumps that have fat-tailed distributions. As fatigue crack propagation is known to leave markings—called striations—on the fracture surface, the distances between these should also have fat-tailed distributions if the crack propagation is intermittent. Here, we combine macroscale crack tip tracking in fatigue crack growth measurements of aluminum 5005 samples with postmortem scanning electron microscopy imaging of the striation lines. We introduce two different methods for extracting the striation line spacing from the images. What we find is a similar distribution of striation spacings as jump sizes using one of our methods, but the average striation spacing does not correlate with the crack growth rate. We conclude that we observe avalanchelike crack propagation, reflected in both the macroscale crack tip tracking as well as the analysis of the fracture surfaces. Our results show that the fracture surfaces can be used to study the intermittency of fatigue crack propagation and in development of crack-resistant materials. The advantages and disadvantages of the two methods introduced are discussed.

关键词： Fracture Material failure Electron microscopy mechanical testing Scanning electron microscopy

Assessment of scoring functions for computational models of protein-protein interfaces

学校读者我要写书评

暂无评论

arXiv 2024年

作者： Sumner, Jacob Meng, Grace Brandt, Naomi Grigas, Alex T. Córdoba, Andrés Shattuck, Mark D. O’Hern, Corey S. Graduate Program in Computational Biology and Bioinformatics Yale University New HavenCT06520 United States Integrated Graduate Program in Physical and Engineering Biology Yale University New HavenCT06520 United States Department of Chemistry Yale University New HavenCT06520 United States Department of Physics Yale University New HavenCT06520 United States Department of Chemistry Duke University DurhamNC27708 United States Department of Physics Duke University DurhamNC27708 United States Benjamin Levich Institute Physics Department City College of New York New YorkNY10031 United States Department of Mechanical Engineering and Materials Science Yale University New HavenCT06520 United States Department of Applied Physics Yale University New HavenCT06520 United States

A goal of computational studies of protein-protein interfaces (PPIs) is to predict the binding site between two monomers that form a heterodimer. The simplest version of this problem is to rigidly re-dock the bound forms of the monomers, which involves generating computational models of the heterodimer and then scoring them to determine the most native-like models. Scoring functions have been assessed previously using rank- and classification-based metrics, however, these methods are sensitive to the number and quality of models in the scoring function training set. We assess the accuracy of seven PPI scoring functions by comparing their scores to a measure of structural similarity to the x-ray crystal structure (i.e. the DockQ score) for a non-redundant set of heterodimers from the Protein Data Bank. For each heterodimer, we generate re-docked models uniformly sampled over DockQ and calculate the Spearman correlation between the PPI scores and DockQ. For some targets, the scores and DockQ are highly correlated;however, for many targets, there are weak correlations. Several physical features can explain the difference between difficult- and easy-to-score targets. For example, strong correlations exist between the score and DockQ for targets with highly intertwined monomers and many interface contacts. We also develop a new score based on only three physical features that matches or exceeds the performance of current PPI scoring functions. These results emphasize that PPI prediction can be improved by focusing on correlations between the PPI score and DockQ and incorporating more discriminating physical features into PPI scoring functions. © 2024, CC BY.

关键词： Monomers

A Pretraining-Finetuning Computational Framework for Material Homogenization

学校读者我要写书评

暂无评论

arXiv 2024年

作者： Wang, Yizheng Li, Xiang Yan, Ziming Ma, Shuaifeng Bai, Jinshuai Liu, Bokai Rabczuk, Timon Liu, Yinghua Zhuang, Xiaoying Department of Engineering Mechanics Tsinghua University Beijing China School of Information Science and Technology Hainan Normal University Haikou China Institute of Structural Mechanics Bauhaus-Universität Weimar Marienstr. 15 Weimar Germany Institute of Photonics Department of Mathematics and Physics Leibniz University Hannover Germany School of Mechanical Medical and Process Engineering Queensland University of Technology Brisbane Australia Department of Applied Physics and Electronics Umeå University Umea Sweden

Homogenization is a fundamental tool for studying multiscale physical phenomena. Traditional numerical homogenization methods, heavily reliant on finite element analysis, demand significant computational resources, especially for complex geometries, materials, and high-resolution problems. To address these challenges, we propose PreFine-Homo, a novel numerical homogenization framework comprising two phases: pretraining and fine-tuning. In the pretraining phase, a Fourier Neural Operator (FNO) is trained on large datasets to learn the mapping from input geometries and material properties to displacement fields. In the fine-tuning phase, the pretrained predictions serve as initial solutions for iterative algorithms, drastically reducing the number of iterations needed for convergence. The pretraining phase of PreFine-Homo delivers homogenization results up to 1000 times faster than conventional methods, while the fine-tuning phase further enhances accuracy. Moreover, the fine-tuning phase grants PreFine-Homo unlimited generalization capabilities, enabling continuous learning and improvement as data availability increases. We validate PreFine-Homo by predicting the effective elastic tensor for 3D periodic materials, specifically Triply Periodic Minimal Surfaces (TPMS). The results demonstrate that PreFine-Homo achieves high precision, exceptional efficiency, robust learning capabilities, and strong extrapolation ability, establishing it as a powerful tool for multiscale homogenization tasks. Copyright © 2024, The Authors. All rights reserved.

关键词： Iterative methods

Ultra-Cold Cryogenic TEM with Liquid Helium and High Stability

学校读者我要写书评

暂无评论

arXiv 2024年

作者： Rennich, Emily Sung, Suk Hyun Agarwal, Nishkarsh Gates, Maya Kerns, Robert Hovden, Robert Baggari, Ismail El The Rowland Institute at Harvard Harvard University CambridgeMA02142 United States Department of Mechanical Engineering University of Michigan Ann ArborMI48109 United States Department of Materials Science and Engineering University of Michigan Ann ArborMI48109 United States Michigan Center for Materials Char-acterization University of Michigan Ann ArborMI48109 United States Applied Physics Program University of Michigan Ann ArborMI48109 United States

Cryogenic transmission electron microscopy has revolutionized structural biology and materials science, but achieving temperatures below the boiling point of liquid nitrogen remains a long-standing aspiration. We introduce an ultra-cold liquid helium transmission electron microscope specimen holder, featuring continuous cryogen flow and vibration decoupling. This instrument is compatible with modern aberration-corrected microscopes and achieves sub-25 K base temperature, ±2 mK thermal stability over many hours, and atomic resolution—setting the stage for a new era of cryogenic electron microscopy. © 2024, CC BY.

关键词： High resolution transmission electron microscopy

Study of background from accidental coincidence signals in the PandaX-Ⅱexperiment

学校读者我要写书评

暂无评论

Chinese physics C 2022年第10期46卷 11-24页

作者： Abdusalam Abdukerim Wei Chen Xun Chen Yunhua Chen Chen Cheng Xiangyi Cui Yingjie Fan Deqing Fang Changbo Fu Mengting Fu Lisheng Geng Karl Giboni Linhui Gu Xuyuan Guo Ke Han Changda He Di Huang Yan Huang Yanlin Huang Zhou Huang Xiangdong Ji Yonglin Ju Shuaijie Li Huaxuan Liu Jianglai Liu Wenbo Ma Yugang Ma Yajun Mao Yue Meng Kaixiang Ni Jinhua Ning Xuyang Ning Xiangxiang Ren Changsong Shang Lin Si Guofang Shen Andi Tan Anqing Wang Hongwei Wang Meng Wang Qiuhong Wang Siguang Wang Wei Wang Xiuli Wang Zhou Wang Mengmeng Wu Shiyong Wu Weihao Wu Jingkai Xia Mengjiao Xiao Pengwei Xie Binbin Yan Jijun Yang Yong Yang Chunxu Yu Jumin Yuan Ying Yuan Xinning Zeng Dan Zhang Tao Zhang Li Zhao Qibin Zheng Jifang Zhou Ning Zhou Xiaopeng Zhou School of Physics and Astronomy Shanghai Jiao Tong UniversityMOE Key Laboratory for Particle Astrophysics and CosmologyShanghai Key Laboratory for Particle Physics and CosmologyShanghai 200240China Shanghai Jiao Tong University Sichuan Research Institute Chengdu 610213China Yalong River Hydropower Development Company Ltd.288 Shuanglin RoadChengdu 610051China School of Physics Sun Yat-Sen UniversityGuangzhou 510275China Tsung-Dao Lee Institute Shanghai 200240China School of Physics Nankai UniversityTianjin 300071China Key Laboratory of Nuclear Physics and Ion-beam Application(MOE) Institute of Modern PhysicsFudan UniversityShanghai 200433China School of Physics Peking UniversityBeijing 100871China School of Physics Beihang UniversityBeijing 102206China Beijing Key Laboratory of Advanced Nuclear Materials and Physics Beihang UniversityBeijing102206China School of Physics and Microelectronics Zhengzhou UniversityZhengzhouHenan 450001China School of Medical Instrument and Food Engineering University of Shanghai for Science and TechnologyShanghai 200093China Department of Physics University of MarylandCollege ParkMaryland 20742USA School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China School of Physics and Key Laboratory of Particle Physics and Particle Irradiation(MOE) Shandong UniversityJinan 250100China Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201210China Center for High Energy Physics Peking UniversityBeijing 100871China

Ⅰ.INTRODUCTION The direct detection of dark matter particles,especially the weakly interacting massive particles(WIMPs),is being actively carried out by a couple of experiments worldwide[1].In recent years,the PandaX-Ⅱ experiment located in the China Jinping Underground Laboratory(CJPL)[1-3],which uses the technology of dual phase liquid xenon time projection chambers(TPCs),has pushed the limits of the cross section between WIMPs and nucleons to a new level for most of the possible WIMP masses;other experiments of the same type are also being performed[4–10].

关键词： dark matter xenon detector background accidental coincidence machine learning