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Ultrastrong Coupling between Polar Distortion and Optical Properties in Ferroelectric MoBr2O2 (vol 146, pg 15411, 2024)

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JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 2024年第32期146卷 22860-22860页

作者： Li, Zhaojun Varrassi, Lorenzo Yang, Yali Franchini, Cesare Bellaiche, Laurent He, Jiangang School of Mathematics and Physics University of Science and Technology Beijing Beijing 100083 China Department of Physics and Astronomy “Augusto Righi” Alma Mater Studiorum Università di Bologna Bologna 40127 Italy Faculty of Physics and Center for Computational Materials Science University of Vienna Kolingasse 14-16 Vienna 1090 Austria Smart Ferroic Materials Center Physics Department and Institute for Nanoscience and Engineering University of Arkansas Fayetteville Arkansas 72701 United States Key Laboratory of Advanced Materials and Devices for Post-Moore Chips Ministry of Education University of Science and Technology Beijing Beijing 100083 China

Tuning the properties of materials by using external stimuli is crucial for developing versatile smart materials. Strong coupling among the order parameters within a single-phase material constitutes a potent foundation for achieving precise property control. However, cross-coupling is fairly weak in most single materials. Leveraging first-principles calculations, we demonstrate a layered mixed anion compound MoBr2O2 that exhibits electric-field switchable spontaneous polarization and ultrastrong coupling between polar distortion and electronic structures as well as optical properties. It offers feasible avenues of achieving tunable Rashba spin-splitting, electrochromism, thermochromism, photochromism, and nonlinear optics by applying an external electric field to a single domain sample and heating, as well as intense light illumination. Additionally, it exhibits an exceptionally large photostrictive effect. These findings not only showcase the feasibility of achieving multiple order parameter coupling within a single material but also pave the way for comprehensive applications based on property control, such as energy harvesting, information processing, and ultrafast control.

关键词： Chemical structure Light materials Phase transitions Polarization

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High-throughput screening of novel silicon allotropes in Fmmm phase with unique electronic physical performances and potential photovoltaic applications

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COMPUTATIONAL materials SCIENCE 2025年 248卷

作者： Jia, Min Fan, Qingyang Gao, Dangli Pang, Qing Yun, Sining Xian Univ Architecture & Technol Coll Sci Xian 710055 Peoples R China Shaanxi Key Lab Nano Mat & Technol Xian 710055 Peoples R China Xian Univ Architecture & Technol Coll Informat & Control Engn Xian 710055 Peoples R China Xian Univ Architecture & Technol Sch Mat Sci & Engn Funct Mat Lab FML Xian 710055 Peoples R China

Pioneer of semiconductor materials, named monocrystalline silicon, holds important applications in solar cells and microelectronics based on their unique semiconductor properties. Here, by a random strategy combined with group and graph theory and high-throughput calculations, 19 new Fmmm phase silicon allotropes have been proposed, including 6 quasi direct or direct band gap semiconductors, 1 metal characteristic allotrope, and 12 indirect band gap semiconductors. The mechanical stability, thermal stability, and dynamic stability of these 19 novel silicon allotropes are thoroughly studied by the elastic constants, relative enthalpies, molecular dynamics, and phonon spectra. As expected, these structures not only meet all stability criterions, but also exhibit excellent physical properties. Especially, these silicon allotropes exhibit three times higher visible light absorption capacity relative to diamond Si, indicating great potential for application in the field of solar photovoltaics. Considering the possibility of laboratory synthesis, we conducted X-ray diffraction for providing more insights into their structure. The design of new silicon allotropes reported in this study may encourage the design and development of smart silicon materials for future more sophisticated application of photoelectricity technology.

关键词： High-throughput calculations Crystal-structure prediction Electronic property Density functional theory Photovoltaic applications

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Optical and electrical characteristics of dome tapered silicon nanowires for efficient photovoltaic solar energy conversion

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Optical and Quantum Electronics 2025年第1期57卷 1-26页

作者： El-Bashar, R. Hameed, Mohamed Farhat O. Abdelhamid, Hamdy Obayya, S.S.A. Cairo University Giza Egypt Centre for Photonics and Smart Materials Zewail City of Science Technology and Innovation October Gardens Giza 6th of October City12578 Egypt Center for Nanotechnology Zewail City of Science Technology and Innovation October Gardens Giza 6th of October City12578 Egypt Mathematics and Engineering Physics Department Faculty of Engineering University of Mansoura Mansoura35516 Egypt Cairo Egypt Electrical Engineering Department College of Engineering and Information Technology Ajman University Ajman United Arab Emirates Zewail City of Science Technology and Innovation October Gardens Giza 6th of October City12578 Egypt Electronics and Communications Engineering Department Faculty of Engineering University of Mansoura Mansoura35516 Egypt

The optical and electrical characteristics of novel dome-shaped nanowires (NWs) are reported for energy harvesting applications. In order to show the superiority of the suggested design, a comparison is made with cylindrical and other tapered nanowires such as conical and horn-shaped NWs. A tapering parameter is introduced to control the NW geometry and its optical and electrical efficiency. Further, the different geometrical parameters are investigated using finite difference time domain to minimize the light reflection and maximize the absorption through the suggested designs. It is evident that the tapering parameter effectively can control the NW-tip geometry to achieve optimum light coupling. The dome-shaped NW design has a good light confinement with better absorption compared to the horn and conical NW structures. This is due to the supported MIE-based mode resonances over a broad wavelength range. Further, the top diameter of the dome-shaped NWs supports more guided modes with high intensity and better light coupling. Besides, the light reflections between the tapered NWs improve the light coupling with the NWs where the optical path length of low frequencies is increased with improved light absorption. Therefore, the reported design with tapering factor of 2.2 achieves an average absorption of 81% with an improvement of 9.5% over the absorption of the conical NWs SC. Further, photo-generated current density and optical efficiency of 37 mA/cm2 and 41% are obtained by the reprted design with an enhancement of 22% and 8.8% compared to conventional cylindrical and conical NWs, respectively. Further, the electrical efficiency is simulated using the finite element method considering the recombination effects. The power conversion efficiency of the dome-shaped array is equal to 15.96%, with an enhancement of 32% and 17.5% relative to cylindrical and conical NWs, respectively. The fine-tapered NW with a dome-shaped design is a crucial step toward realizing highly e

关键词： Domes

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Ion compaction effect in hollow FePt nanochains with ultrathin shell under low energy ion irradiation

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Nano Research 2022年第10期15卷 9309-9318页

作者： Jialong Liu Jianguo Wu Long Cheng Suyun Niu Zhiqiang Wang Mengyuan Zhu Jingyan Zhang Shouguo Wang Wei Wang School of Mathematics and Physics Beijing University of Chemical TechnologyBeijing 100029China Key Laboratory of Shale Gas and Engineering Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Innovation Academy for Earth Science Chinese Academy of SciencesBeijing 100029China School of Physics Beihang UniversityBeijing 100029China Beijing Hangxing Machinery Manufacturing Co. Ltd.Beijing 100013China Beijing Smart-chip Microelectronics Technology Co. Ltd.Beijing 100192China Beijing Advanced Innovation Center for Materials Genome Engineering School of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing 100083China

The morphology manipulation of nanomaterials by ion irradiation builds a way to precisely control physicochemical *** the continuous irradiation of low energy Ga+,Ne+,and He+ions,an ion compaction effect has been found in hollow FePt nanochains with ultrathin shell that the volumes of the nanochains are gradually compacted by *** deep learning algorithm has been successfully applied to automatically and precisely measure average sizes of spheres in hollow FePt *** compaction under ion irradiation is very fast in the very early period and then proceeds to a slow *** compaction rates in both regions are linearly fitted and all the values are in the order of 10^(–17) to 10^(–14) cm^(2)/*** species and ion current have effect on the compaction *** example,the compaction rate of Ga+ions is larger than those of Ne+and He+ions under an identical current,while irradiation with larger current can compact nanochains *** ion compaction effect originates from the local shear deformation caused by the interaction between incident ions and the electrons of Fe and Pt atoms in the ultrathin *** continuous irradiation,the crystalline clusters of FePt nanchains firstly grow larger and then become *** ion compaction effect can be applied to tune the size and crystal structure of hollow structures with a precise rate by choosing appropriate ion species and current.

关键词： ion compaction effect hollow structure ion irradiation FePt

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Variational functionals for the driven quantum harmonic oscillator

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COMPLEX VARIABLES AND ELLIPTIC EQUATIONS 2021年第2期66卷 312-335页

作者： Devillanova, G. Florio, G. Maddalena, F. Politecn Bari Dipartimento Meccan Matemat Management Bari Italy Ist Nazl Fis Nucl Sez Bari Bari Italy

We study some variational problems related to the controllability of the transition between two quantum states of the driven quantum harmonic oscillator. We focus on the existence of minimum points of the total energy functional which is obtained by adding to the cost of the control a term penalizing the distance from the maximum transition probability between given energy states.

关键词： G Molica Bisci Quantum control quantum oscillator calculus of variations optimal control problem

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Design Low Elastic Modulus Ti-Zr-Nb-Hf-Cu Multi-Principal Element Alloys for Dental Application

SSRN

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SSRN 2025年

作者： Zhao, Zhichao Liu, Bo Wang, Donghui Jiang, Jing Lu, Zhen Yang, Lei School of Materials Science and Engineering Hebei University of Technology Tianjin300131 China Center for Health Science and Engineering Hebei Key Laboratory of Biomaterials and Smart Theranostics School of Health Sciences and Biomedical Engineering Hebei University of Technology Tianjin300131 China Institute of Physics Chinese Academy of Sciences Beijing100190 China School of Physical Sciences University of Chinese Academy of Sciences Beijing100049 China Mathematics for Advanced Materials Open Innovation Laboratory

Titanium and titanium alloys have been widely used as dental implant materials due to their excellent strength, stability, and biocompatibility. However, in clinical practice, the relatively high modulus of elasticity of titanium implants usually triggers the phenomenon of stress shielding, accompanied by the risk of post-implantation infection, which hinders the regeneration and reconstruction of bone tissue and may ultimately lead to implant failure. Multi-principal element alloys (MPEAs) offer enhanced control over the modulus due to their broad compositional variability. Herein, three MPEAs with the composition (TixZrxNbHf)95Cu5 (x = 2, 3, 4) were developed in this paper, which exhibits a lower modulus of elasticity contrast with Ti6Al4V, and the addition of copper (Cu) is effective in suppressing post-implantation infection. These three MPEAs are primarily composed of body-centered cubic (BCC) structures and demonstrate excellent mechanical properties, including compressive plastic strain exceeding 40%, yield strength up to 840 MPa, and a minimum elastic modulus of just 69 GPa, which is similar to that of human bone. Furthermore, the low elastic modulus MPEAs exhibit outstanding corrosion resistance in simulated body fluids, enhancing their durability under physiological conditions. In vitro cellular experiments confirm their excellent cytocompatibility and ability to promote angiogenesis, while in vitro bacterial studies demonstrate antimicrobial efficacy, with a rate exceeding the specified 90%. In vivo experiments also further validated the osseointegration capacity. Incorporating copper into MPEAs with BCC structures presents a promising avenue for developing advanced dental implant materials. © 2025, The Authors. All rights reserved.

关键词： Corrosion resistance

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Modelling of deformation and fracture of composite structures using monitoring data from optical fiber strain sensors 9

Modelling of deformation and fracture of composite structure...

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9th ECCOMAS Thematic Conference on smart structures and materials, smart 2019

作者： Tashkinov, Mikhail A. Matveenko, Valerii P. Faculty of Applied Mathematics and Mechanics Perm National Research Polytechnic University Komsomolsky Ave. 29 Perm614990 Russia Institute of Continuous Media Mechanics Russian Academy of Science Academician Korolev Street 1 Perm614013 Russia

ISBN: (纸本)9788494919466

An iterative algorithm for refinement of elastic constant of composite laminates is offered. It comprises solution of the inverse problems in accordance with the data received from the fiber Bragg grating (FBG) sensors embedded into composite structure to ensure a match with a given precision of numerical and experimental results for strain values at the control points. The adjusted values of the constants allow to deliver more accurate simulation results using numerical models of mechanical behavior of the structures. © 2019 9th ECCOMAS Thematic Conference on smart structures and materials, smart 2019. All rights reserved.

关键词： Inverse problems

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Dynamic optimal control of energy in buildings adapted to predictions of external factors 9

Dynamic optimal control of energy in buildings adapted to pr...

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9th ECCOMAS Thematic Conference on smart structures and materials, smart 2019

作者： Ayed, Samah Ben Kim, Donghun Borggaard, Jeff Cliff, Eugene Department of Engineering Technology and Surveying Engineering New Mexico State University P.O. Box 30001 Las CrucesNM88003 United States School of Mechanical Engineering Purdue University West LafayetteIN47907 United States Interdisciplinary Center for Applied Mathematics Virginia Polytechnic Institute State University Wright House West Campus Drive BlacksburgVA24061 United States

ISBN: (纸本)9788494919466

Sports facilities have high energy requirements and therefore, presents a great opportunity for energy savings. In fact, people generate a significant sensible and latent heat because of high activity level and the amount of moisture released through exercising activities and showers. These buildings are more challenging to control because of the specific occupants requirements. In this effort, dynamic control of roof top units subject to external weather predictions is implemented on a case study of a gymnasium. The control model is an an optimal controller based on a reduced order model of CFD simulations of the indoor air, coupled to an envelope model. © 2019 9th ECCOMAS Thematic Conference on smart structures and materials, smart 2019. All rights reserved.

关键词： Gymnasiums

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STRUCTURAL INTENSITY ANALYSIS OF PERIODIC ELASTIC structures WITH FREQUENCY STOP BANDS

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ASME Conference on smart materials, Adaptive structures and Intelligent Systems

作者： Nouh, M. SUNY Buffalo Sound & Vibrat Lab Dept Mech & Aerosp Engn Buffalo NY 14260 USA

ISBN: (纸本)9780791850497

Periodic elastic structures consisting of self-repeating geometric or material arrangements exhibit unique wave propagation characteristics culminating in frequency stop bands, i.e. ranges of frequency where elastic waves can propagate the periodic medium. Such features make periodic structures appealing for a wide range of vibration suppression and noise control applications. Stop bands in periodic media are achieved via Bragg scattering of elastic which is attributed to impedance mismatches between the different constituents of the self-repeating cells. Stop band frequencies can be numerically predicted using mathematical models which generally utilize the Bloch wave theorem and a transfer matrix method to track the spatial and temporal parameters of the propagating waves from one cell to the next. Such analysis generates what is referred to as the band structure (or the dispersion curves) of the periodic medium which can be used to predict the location of the pass and stop bands. Although capable, these models become significantly more involved when analyzing structures with dissipative constituents and/or material damping and need further adjustments to account for complex elastic moduli and frequency dependent loss factors. A new approach is presented which relies on evaluating structural intensity parameters, such as the active vibrational power and energy transmission paths. It is shown that the steady-state spatial propagation of vibrational power caused by an external disturbance accurately reflects the wave propagation pattern in the periodic medium, and can thus be reverse engineered to numerically predict the stop band frequencies for different degrees of damping via a stop band index (SBI). The developed framework is mathematically applied to a one-dimensional periodic rod to validate the proposed method.

关键词： Noise control Radiation scattering Wave propagation Theorems (mathematics) Scattering (Physics) Waves Electromagnetic scattering Elastic moduli Elastic waves Vibration suppression Steady state Periodic structures Damping

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A novel technique for optimal placement of piezoelectric actuators on smart structures

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JOURNAL OF THE FRANKLIN INSTITUTE-ENGINEERING AND APPLIED mathematics 2011年第1期348卷 12-23页

作者： Mehrabian, Ali Reza Yousefi-Koma, Aghil Concordia Univ Dept Elect & Comp Engn Fac Engn & Comp Sci Montreal PQ H3G 1M8 Canada Univ Tehran Adv Dynam & Control Syst Lab Sch Mech Engn Tehran Iran

The problem of positioning of actuators and sensors on smart materials has been a point of interest in recent years. This is due to the fact that in many practical applications there are limitations in space, weight, etc. of the smart structures, which make the problem of positioning more complex. In addition, it is required that the actuators/sensors have the best possible performance. The development of smart structures technology in recent years has provided numerous opportunities for vibration control applications. The use of piezoelectric ceramics or polymers has shown great promise in the development of this technology. The employment of piezoelectric material as actuators in vibration control is beneficial because these actuators only excite the elastic modes of the structures without exciting the rigid-body modes. This is important since very often only elastic motions of the structures are needed to be controlled. The purpose of this paper is to introduce a novel approach developed for optimizing the location of piezoelectric actuators for vibration suppression of flexible structures. A flexible fin with bonded piezoelectric actuators is considered in this study. The frequency response function (FRF) of the system is then recorded and maximization of the FRF peaks is considered as the objective function of the optimization algorithm to find the optimal placement of the piezoelectric actuators on the smart fin. Three multi-layer perceptron neural networks are employed to perform surface fitting to the discrete data generated by the finite element method (FEM). Invasive weed optimization (IWO), a novel numerical stochastic optimization algorithm, is then employed to maximize the weighted summation of FRF peaks. Results indicate an accurate surface fitting for the FRF peak data and an optimal placement of the piezoelectric actuators for vibration suppression is achieved. (C) 2009 The Franklin Institute. Published by Elsevier Ltd. All rights reserved.

关键词： smart structures Vibration control Neural networks Optimization Invasive weed optimization

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