检索结果-内蒙古大学图书馆

Generation of terahertz transients from Co2Fe0.4Mn0.6Si-Heusler-alloy/normal-metal nanobilayers excited by femtosecond optical pulses

引用

Physical Review Research 2021年第4期3卷 043025-043025页

作者： Sarah Heidtfeld Roman Adam Takahide Kubota Koki Takanashi Derang Cao Carolin Schmitz-Antoniak Daniel E. Bürgler Fangzhou Wang Christian Greb Genyu Chen Ivan Komissarov Hilde Hardtdegen Martin Mikulics Roman Sobolewski Shigemasa Suga Claus M. Schneider Research Centre Jülich Peter Grünberg Institute 52425 Jülich Germany Faculty of Physics University of Duisburg-Essen 47048 Duisburg Germany Institute for Materials Research Tohoku University Sendai 980-8577 Japan Center for Spintronics Research Network Tohoku University Sendai 980-8577 Japan Center for Science and Innovation in Spintronics (Core Research Cluster) Tohoku University Sendai 980-8577 Japan College of Physics National Demonstration Center for Experimental Applied Physics Education Qingdao University Qingdao 266071 China Materials Science Graduate Program University of Rochester Rochester New York 14627 USA Laboratory for Laser Energetics University of Rochester Rochester New York 14623 USA Department of Electrical and Computer Engineering University of Rochester Rochester New York 14627 USA Belarusian State University of Informatics and Radioelectronics Minsk 220013 Belarus Research Centre Jülich Ernst Ruska Centre for Microscopy and Spectroscopy with Electrons 52425 Jülich Germany Department of Physics and Astronomy University of Rochester Rochester New York 14627 USA The Institute of Scientific and Industrial Research Osaka University Ibaraki Osaka 567-0047 Japan Department of Physics University of California Davis Davis California 95616 USA

We generated pulses of electromagnetic radiation in the terahertz (THz) frequency range by optical excitation of Co2Fe0.4Mn0.6Si (CFMS)/normal-metal (NM) bilayer structures. The CFMS is a Heusler alloy showing a band gap in one spin channel and is therefore a half metal. We compared the THz emission efficiency in a systematic manner for four different CFMS/NM bilayers, where NM was either Pt, Ta, Cr, or Al. Our measurements show that the THz intensity is highest for a Pt capping. We also demonstrate the tunability of the THz amplitude by varying the magnetic field for all four bilayers. We attribute the THz generation to the inverse spin Hall effect. In order to investigate the role of the interface in THz generation, we measured the spin mixing conductance for each CFMS/NM bilayer using a ferromagnetic resonance method. We found that the spin-orbit coupling cannot completely describe the THz generation in the bilayers and that the spin transmission efficiency of the CFMS/NM interface and the spin diffusion length, as well as the oxidation of the NM layer, play crucial roles in the THz emission process.

关键词： Inverse spin Hall effect Magnetism Spin injection Spin pumping Spintronics Ferromagnetic resonance Terahertz time-domain spectroscopy

来源：评论

学校读者我要写书评

暂无评论

Flexible cellulose-carbon nanotube paper substrate decorated with PZT: sensor properties

Flexible cellulose-carbon nanotube paper substrate decorated...

引用

MRS Advances

作者： Silva, Ricardo M. Noremberg, Bruno S. Marins, Natália H. Alano, Jose H. Santana, Luiza R. Valentini, Antoninho Lukowiec, Dariusz Tański, Tomasz Carreño, Neftalí L.V. Graduate Program in Materials Science and Engineering Technology Development Center Federal University of Pelotas PelotasRS96010-000 Brazil Federal University of Ceará Department of Analytical Chemistry and Chemical Physics FortalezaCE Brazil Institute of Engineering Materials and Biomaterials Silesian University of Technology Gliwice Poland Center for Nanotechnology Silesian University of Technology Gliwice Poland

Composite of PZT (lead zirconate titanate) and PLZT (lead lanthanum zirconate titanate) along an organic, renewable, conductive, and flexible matrix have been developed. The conductive paper was obtained through the reaction between the cellulose extracted from banana stem and functionalized MWCNT. This reaction was made in the presence of hydrogen (from H2SO4), which reduced the size of the cellulose by acid hydrolysis and promotes the interaction between its hydroxyls and the carboxyl groups of nanotubes. Afterward, the PZT particles were synthesized and grown up on the conductive paper by microwaves-assisted hydrothermal synthesis (MHS). The composite material was characterized by structure and morphology. Moreover, gas-sensing in the presence of methanol and electrical resistance as a function of temperature were also investigated. In this way, a simple, low-cost and successful synthesis was reported. Also, a promising flexible was obtained using a chemical transformation process from banana residue as source of cellulose. Copyright © materials Research Society 2018.

关键词： Cellulose

来源：评论

学校读者我要写书评

暂无评论

Magnetic Control of Soft Chiral Phonons in PbTe

arXiv

引用

arXiv 2021年

作者： Baydin, Andrey Hernandez, Felix G.G. Rodriguez-Vega, Martin Okazaki, Anderson K. Tay, Fuyang Timothy Noe, G. Katayama, Ikufumi Takeda, Jun Nojiri, Hiroyuki Rappl, Paulo H.O. Abramof, Eduardo Fiete, Gregory A. Kono, Junichiro Department of Electrical and Computer Engineering Rice University HoustonTX77005 United States Smalley-Curl Institute Rice University HoustonTX77005 United States Instituto de Física Universidade de São Paulo SP São Paulo05508-090 Brazil Theoretical Division Los Alamos National Laboratory Los AlamosNM87545 United States Laboratório Associado de Sensores e Materiais Instituto Nacional de Pesquisas Espaciais SP São José dos Campos12201-970 Brazil 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 Department of Physics Northeastern University BostonMA02115 United States Department of Physics Massachusetts Institute of Technology CambridgeMA02139 United States Department of Physics and Astronomy Rice University HoustonTX77005 United States Department of Material Science and NanoEngineering Rice University HoustonTX77005 United States

PbTe crystals have a soft transverse optical phonon mode in the terahertz frequency range, which is known to efficiently decay into heat-carrying acoustic phonons, resulting in anomalously low thermal conductivity. Here, we studied this phonon via polarization-dependent terahertz spectroscopy. We observed softening of this mode with decreasing temperature, indicative of incipient ferroelectricity, which we explain through a model including strong anharmonicity with a quartic displacement term. In magnetic fields up to 25 T, the phonon mode splits into two modes with opposite handedness, exhibiting circular dichroism. Their frequencies display Zeeman splitting together with an overall diamagnetic shift with increasing magnetic field. Using a group-theoretical approach, we demonstrate that these observations are the result of magnetic field-induced morphic changes in the crystal symmetries through the Lorentz force exerted on the lattice ions. Thus, our study reveals a novel process of controlling phonon properties in a soft ionic lattice by a strong magnetic field. Copyright © 2021, The Authors. All rights reserved.

关键词： Magnetic fields

来源：评论

学校读者我要写书评

暂无评论

Observation of topological polaritons and photonic magic angles in twisted van der Waals bi-layers

arXiv

引用

arXiv 2020年

作者： Alù, Andrea Krasnok, Alex Dai, Zhigao Wu, Jing Qiu, Cheng-Wei Wu, Yingjie Bao, Qiaoliang Si, Guangyuan Ou, Qingdong Hu, Guangwei Mazor, Yarden Zhang, Qing Department of Electrical and Computer Engineering National University of Singapore Singapore Singapore Photonics Initiative Advanced Science Research Center City University of New York New YorkNY United States Monash University ClaytonVIC Australia Melbourne Centre for Nanofabrication Victorian Node of the Australian National Fabrication Facility ClaytonVIC Australia Singapore Singapore Faculty of Materials Science and Chemistry China University of Geosciences 388 Lumo Road Wuhan430074 China Department of Electrical and Computer Engineering University of Texas at Austin AustinTX United States Physics Program Graduate Center City University of New York New YorkNY United States

来源：评论

学校读者我要写书评

暂无评论

Disorder-driven glasslike thermal conductivity in colusite Cu26V2Sn6S32 investigated by Mössbauer spectroscopy and inelastic neutron scattering

引用

Physical Review materials 2020年第2期4卷 025404-025404页

作者： Christophe Candolfi Gabin Guélou Cédric Bourgès Andrew R. Supka Rabih Al Rahal Al Orabi Marco Fornari Bernard Malaman Gérard Le Caër Pierric Lemoine Vincent Hardy Jean-Marc Zanotti Raju Chetty Michihiro Ohta Koichiro Suekuni Emmanuel Guilmeau Institut Jean Lamour UMR 7198 CNRS – Université de Lorraine 2 allée André Guinier-Campus ARTEM BP 50840 54011 Nancy Cedex France Laboratoire CRISMAT UMR 6508 CNRS ENSICAEN 6 Boulevard du Maréchal Juin 14050 Caen Cedex 04 France Department of Physics and Science of Advanced Materials Program Central Michigan University Mt. Pleasant Michigan 48859 United States Solvay Design and Development of Functional Materials Department AXEL’ ONE Collaborative Platform − Innovative Materials 87 Rue des Freres Perret − BP62 69192 Saint Fons Cedex France Institut de Physique de Rennes UMR UR1-CNRS 6251 Université de Rennes I Campus de Beaulieu 35042 Rennes Cedex France Université de Rennes CNRS ISCR – UMR 6226 F-35000 Rennes France Laboratoire Léon Brillouin CNRS-CEA (UMR 12) CNRS Université Paris-Saclay CEA Saclay 91191 Gif-sur-Yvette Cedex France Research Institute for Energy Conservation National Institute of Advanced Industrial Science and Technology (AIST) Tsukuba Ibaraki 305–8568 Japan Department of Applied Science for Electronics and Materials Interdisciplinary Graduate School of Engineering Sciences Kyushu University Kasuga Fukuoka 816–8580 Japan

The influence of structural disorder on the thermal transport in the colusite Cu26V2Sn6S32 has been investigated by means of low-temperature thermal conductivity and specific heat measurements (2–300 K), Sn119 Mössbauer spectroscopy and temperature-dependent powder inelastic neutron scattering (INS). Variations in the high-temperature synthesis conditions act as a key parameter for tuning the degree of disorder in colusite compounds. Intriguingly, we find that all synthesized samples are disordered, the degree of which varies with the synthesis conditions used. Mössbauer data clearly evidence that Sn atoms do not solely occupy the 6c site of the crystal lattice but are present on possibly both the Cu and V sites, leading to a random distribution of these three cations within the unit cell. Increasing the disorder in these materials tends to lead to a smearing out of the main features in the phonon density of states measured by INS. Although the evolution of the inelastic signal upon warming is well described by a quasiharmonic approximation, elastic properties calculations indicate large average Grüneisen parameters, consistent with those determined experimentally from thermodynamic data. Increasing the level of disorder results in a decreased average Grüneisen parameter suggesting that the lowered lattice thermal conductivity is not driven by enhanced anharmonicity. These results provide experimental evidence to support that the remarkable changeover in the lattice thermal conductivity from crystalline to glasslike is solely driven by enhanced disorder accompanied by local lattice distortions.

关键词： Thermal properties Polycrystalline materials Mössbauer spectroscopy Time-of-flight neutron spectroscopy

来源：评论

学校读者我要写书评

暂无评论

Density functional study on the oxygen evolution reaction mechanism of transition metal doped bimetallic NiCu phosphate surface

引用

Computational and Theoretical Chemistry 2025年 1250卷

作者： Hamdi Ikhwan Dzaki Ahmad Syaifullah Muhammad Arkan Nuruzzahran Nadhratun Naiim Mobarak Sasfan Arman Wella Fadjar Fathurrahman Ni Luh Wulan Septiani Adhitya Gandaryus Saputro Graduate Program of Engineering Physics Faculty of Industrial Technology Institut Teknologi Bandung Bandung West Java 40132 Indonesia PT. PLN (Persero) Indonesia Department of Chemical Sciences Faculty of Science and Technology Universiti Kebangsaan Malaysia 43600 UKM Bangi Selangor Darul Ehsan Malaysia Research Center for Quantum Physics National Research and Innovation Agency (BRIN) South Tangerang 15314 Indonesia Collaboration Research Center for Advanced Energy Materials BRIN - Institut Teknologi Bandung Bandung 40132 Indonesia Quantum and Nano Technology Research Group Bandung Institute of Technology Bandung 40132 Indonesia Research Centre for Nanoscience and Nanotechnology Institut Teknologi Bandung Bandung West Java 40132 Indonesia Research Center for Electronics National Research and Innovation Agency KST Samaun Samadikun Bandung 40135 Indonesia

We have explored the oxygen evolution reaction (OER) activity of both undoped nickel copper phosphate (NiCuPO) and transition metal-doped NiCuPO-M (M = Mn, Fe, Co) surfaces using periodic density functional theory (DFT)-based calculations. Our findings highlight that while the undoped NiCuPO surface exhibits a high overpotential of 0.98 V, the introduction of transition metal doping remarkably enhances the OER performance, reducing the overpotential to as low as 0.41 V in the Mn-doped case, outperforming the widely used IrO 2 catalyst. This enhancement is primarily due to a favorable shift in the d -band center, which increases O* adsorption strength and decreases the OER overpotential. Among the doped systems, Mn and Fe doping demonstrate the most substantial reductions in overpotential, underscoring their potential as efficient catalysts for OER applications.

关键词： DFT NiCu phosphate Oxygen evolution reaction Transition metal doping Water electrolysis

来源：评论

学校读者我要写书评

暂无评论

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

引用

Soft matter 2021年第21期17卷 5444页

作者： Hend Baza Taras Turiv Bing-Xiang Li Ruipeng Li Benjamin M Yavitt Masafumi Fukuto Oleg D Lavrentovich Department of Physics Kent State University Kent OH 44242 USA. olavrent@kent.edu and Advanced Materials and Liquid Crystal Institute Kent State University Kent OH 44242 USA. Advanced Materials and Liquid Crystal Institute Kent State University Kent OH 44242 USA and Materials Science Graduate Program Kent State University Kent OH 44242 USA. National Synchrotron Light Source II Brookhaven National Laboratory Upton NY 11973 USA. National Synchrotron Light Source II Brookhaven National Laboratory Upton NY 11973 USA and Department of Materials Science and Chemical Engineering Stony Brook University Stony Brook NY 11794 USA. Department of Physics Kent State University Kent OH 44242 USA. olavrent@kent.edu and Advanced Materials and Liquid Crystal Institute Kent State University Kent OH 44242 USA and Materials Science Graduate Program Kent State University Kent OH 44242 USA.

Correction for 'Shear-induced polydomain structures of nematic lyotropic chromonic liquid crystal disodium cromoglycate' by Hend Baza et al., Soft Matter, 2020, 16, 8565-8576.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Terahertz chiral photonic-crystal cavities for Dirac gap engineering in graphene

引用

Nature communications 2025年第1期16卷 5270页

作者： Fuyang Tay Stephen Sanders Andrey Baydin Zhigang Song Davis M Welakuh Alessandro Alabastri Vasil Rokaj Ceren B Dag Junichiro Kono Department of Electrical and Computer Engineering Rice University Houston TX USA. fuyang.tay@columbia.edu. Applied Physics Graduate Program Smalley-Curl Institute Rice University Houston TX USA. fuyang.tay@columbia.edu. Department of Electrical and Computer Engineering Rice University Houston TX USA. Smalley-Curl Institute Rice University Houston TX USA. Rice Advanced Materials Institute Rice University Houston TX USA. John A. Paulson School of Engineering and Applied Sciences Harvard University Cambridge MA USA. Max Planck Institute for the Structure and Dynamics of Matter Hamburg Germany. Department of Physics Harvard University Cambridge MA USA. ITAMP Harvard-Smithsonian Center for Astrophysics Cambridge MA USA. Department of Physics Villanova University Villanova PA USA. Department of Physics Indiana University Bloomington IN USA. Department of Electrical and Computer Engineering Rice University Houston TX USA. kono@rice.edu. Smalley-Curl Institute Rice University Houston TX USA. kono@rice.edu. Rice Advanced Materials Institute Rice University Houston TX USA. kono@rice.edu. Department of Physics and Astronomy Rice University Houston TX USA. kono@rice.edu. Department of Materials Science and NanoEngineering Rice University Houston TX USA. kono@rice.edu.

Strong coupling between matter and vacuum electromagnetic fields in a cavity can induce novel quantum phases in thermal equilibrium via symmetry breaking. Particularly intriguing is the coupling with circularly polarized cavity fields, which can break time-reversal symmetry (TRS) and lead to topological bands. This has spurred significant interest in developing chiral cavities that feature broken TRS, especially in the terahertz (THz) frequency range, where various large-oscillator-strength resonances exist. Here, we present a design for high-quality-factor THz chiral photonic-crystal cavities (PCCs) that achieve broken TRS using a magnetoplasma in a lightly doped semiconductor. We incorporate ab initio density functional theory calculations into the derived microscopic model, allowing a realistic estimate of the vacuum-induced gap in graphene when coupled to our chiral cavity. Our calculations show an enhancement in the light-matter interaction due to Dirac nodes and predict an energy gap on the order of 1 meV. The THz chiral PCCs offer a promising platform for exploring cavity-dressed condensed matter with broken TRS.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Using physical features of protein core packing to distinguish real proteins from decoys

arXiv

引用

arXiv 2020年

作者： Grigas, Alex T. Mei, Zhe Treado, John D. Levine, Zachary A. Regan, Lynne 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 Mechanical Engineering and Materials Science Yale University New HavenCT06520 United States Department of Pathology Yale University New HavenCT06520 United States Department of Molecular Biophysics and Biochemistry Yale University New HavenCT06520 United States Institute of Quantitative Biology Biochemistry and Biotechnology Centre for Synthetic and Systems Biology School of Biological Sciences University of Edinburgh Department of Physics Yale University New HavenCT06520 United States Department of Applied Physics Yale University New HavenCT06520 United States

The ability to consistently distinguish real protein structures from computationally generated model decoys is not yet a solved problem. One route to distinguish real protein structures from decoys is to delineate the important physical features that specify a real protein. For example, it has long been appreciated that the hydrophobic cores of proteins contribute signifficantly to their stability. As a dataset of decoys to compare with real protein structures, we studied submissions to the bi-annual CASP competition (speciffically CASP11, 12, and 13), in which researchers attempt to predict the structure of a protein only knowing its amino acid sequence. Our analysis reveals that many of the submissions possess cores that do not recapitulate the features that define real proteins. In particular, the model structures appear more densely packed (because of energetically unfavorable atomic overlaps), contain too few residues in the core, and have improper distributions of hydrophobic residues throughout the structure. Based on these observations, we developed a deep learning method, which incorporates key physical features of protein cores, to predict how well a computational model recapitulates the real protein structure without knowledge of the structure of the target sequence. By identifying the important features of protein structure, our method is able to rank decoys from the CASP competitions equally well, if not better than, state-of-the-art methods that incorporate many additional features. Copyright © 2020, The Authors. All rights reserved.

关键词： Proteins

来源：评论

学校读者我要写书评

暂无评论

Fabrication and photocatalytic activity of TiO2 composite membranes via simultaneous electrospinning and electrospraying process

引用

Journal of Environmental sciences 2018年第10期30卷 13-24页

作者： Taddao Pahasup-anan Kowit Suwannahong Wipada Dechapanya Ratthapol Rangkupan International Program in Hazardous Substance and Environmental Management Graduate School Chulalongkorn UniversityBangkok 10330Thailand Center of Excellence on Hazardous Substance Management (HSM) Bangkok 10330 Thailand Department of Public Health Faculty of Public Health Western UniversityKanchanaburi 71170 Thailand Department of Chemical Engineering Faculty of Engineering Ubonratchathani UniversityUbonratchathani 34190 Thailand Metallurgy and Materials Science Research Institute Chulalongkorn University Bangkok 10330 Thailand Nanotec-CU Center of Excellence on Food and Agriculture Chulalongkorn UniversityBangkok 10330 Thailand

In present study, a simultaneous electrospinning and electrospraying（SEE） process was employed to produce microclusters of TiO2 nanoparticles and interlock them in nanofibrous network. The photocatalytic composite membranes（PCMs） were fabricated by electrospraying TiO2 nanoparticle suspension into microcluster form that dispersed and entrapped within nylon-6 electrospun fiber membrane. Three PCMs membrane with TiO2 content of 52.0, 83.6,and 91.7 wt.% were successfully fabricated. The membrane consisted of TiO2 microclusters,ranging in sizes from around 0.3 to 10 μm, distributed uniformly within the nylon-6 nanofibrous network. PCMs photocatalytic activity against Methylene Blue（MB） in aqueous solution showed more than 98% MB removal efficiency after 120 min of photocatalytic oxidation（PCO） for all PCMs. For PCM with the highest TiO2 content tested for 5 PCO cycles, it was found that most of their TiO2 content remained incorporated within the nanofibrous structure. The concept of nanoparticles clusters entrapment with SEE fabrication employed here provide a simple and effective method for reducing detachment of nanostructure phase from nanocomposite membrane.

关键词： Nanocomposites Electrospinning Electrospraying TiO2 Photocatalysis

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：