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Influence of erbium on structural,and charged particles,photons,and neutrons shielding properties of Ba_(1-x)Er_(x)SnO_(3) perovskite ceramics

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Journal of Rare Earths 2024年第4期42卷 724-732页

作者： M.K.h.Hamad Nidal Dwaikat M.H.A.Mhareb M.I.Sayyed R.M.Hamad Y.S.M.Alajerami M.A.Almessiere Gameel Saleh Ahmad Hussein Alomari K.A.Ziq Department of Basic Sciences School of Social and Basics SciencesAl Hussein Technical UniversityKing Abdullah II St 242Amman11831Jordan Department of Physics College of Engineering and PhysicsInterdisciplinary Research Center for Advanced MaterialsKing Fahd University of Petroleum&MineralsDhahran31261Saudi Arabia Department of Physics College of ScienceImam Abdulrahman Bin Faisal UniversityP.O.Box 1982Dammam31441Saudi Arabia Basic and Applied Scientific Research Center Imam Abdulrahman Bin Faisal UniversityP0.Box 1982Dammam31441Saudi Arabia Department of Physics Faculty of ScienceIsra UniversityAmman11622Jordan Department of Nuclear Medicine Research Institute for Research and Medical Consultations(IRMC)Imam Abdulrahman Bin Faisal UniversityPo.Box 1982Dammam31441Saudi Arabia Medical Imaging Department Applied Medical Sciences FacultyAl Azhar University-Gaza CityPo.Box 1277Palestine Department of Biophysics Institute for Research and Medical Consultations(IRMC)Imam Abdulrahman Bin Faisal UniversityPo.Box1982Dammam 31441Saudi Arabia Department of Biomedical Engineering College of EngineeringImam Abdulrahman Bin Faisal UniversityPo.Box 1982Dammam31441Saudi Energy&Minerals Regulatory Commission Amman11821Jordan

Five perovskite ceramics samples of Ba_(1-x)Er_(x)SnO_(3) with x=0.00,0.05,0.10,0.15,and 0.20 were synthesized using the conventional solid-state reaction method.The prepared samples were characterized by X-ray diffraction(XRD),Fourier transforms infrared(FTIR),and UV-Vis spectroscopy.The shielding properties against ionizing radiation were also investigated.The XRD analysis shows the perovskite cubic structure as the major phase in all samples.The FTIR reveals a distinctive band around 614-620 cm^(-1) ascribed to the antisymmetric O-Sn-O vibration.UV-Vis spectroscopy was used to determine the bandgap according to diffuse reflectance,and the results display a fixed enhancement in the bandgap from 3.2 to 3.3 eV for all samples.Gamma-ray shielding properties of the synthesized samples were experimentally measured and compared with XCOM computational results.The relative differences(Δ,%)between experimental and theo retical values are low and fall within the 0.446%-7.10%range.The addition of Er leads to the enhanced density,neutron,and gamma shielding features.In contrast,charged particles’shielding parameters gradually reduce with rising Er contents.These results suggest that Ba_(1-x)Er_(x)SnO_(3) samples can be used in different radiation shielding applications.

关键词： Perovskite ceramics Gamma ray shielding Mass stopping power Rare earths

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Ultrabright near-infrared light

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Light(Science & Applications) 2024年第4期13卷 609-609页

作者： Andries Meijerink Debye Institute for Nanomaterials Science Utrecht UniversityPrincetonplein

Nature Photonics(2024)https://***/10.1038/s41566-024-01400-7 The recent race for bright and broadband near-infrared(NIR)light sources has focused on new luminescent materials(phosphors)for efficient conversion of blue light emitting diode(LED)emission to broadband NIR.For extreme brightness,blue laser diodes(LDs)are superior to LEDs as they maintain efficiency at high current density.However,so far NIR phosphors suffered from severe efficiency droop at these high pumping powers.The team of Zhiguo Xia from South China University of Technology reported a record high 6 Watt NIR output from LDpumped MgO:Cr^(3+)translucent ceramics emitting around 810 nm.Interestingly,MgO:Cr^(3+)is an old phosphor,extensively studied in the past century.The success is based in spark plasma sintering of translucent MgO:Cr^(3+)ceramics using nanosilica as flux,incorporated at grain boundaries.The refractive index contrast between MgO and SiO2 induces scattering of blue light,increasing light absorption,and the dense ceramic has excellent thermal conductivity,reducing thermal quenching of NIR emission.The new scheme using NIR-emitting translucent ceramics for laser-driven NIR light sources will propel photonics applications in night vision,biomedical imaging and sensing.

关键词： ceramics ceramic maintain

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Design high-entropy carbide ceramics from machine learning

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npj Computational Materials 2022年第1期8卷 36-47页

作者： Jun Zhang Biao Xu Yaoxu Xiong Shihua Ma Zhe Wang Zhenggang Wu Shijun Zhao Department of Mechanical Engineering City University of Hong KongHong KongChina College of Materials Science and Engineering Hunan UniversityChangshaHunan410082China City University of Hong Kong Shenzhen Research Institute ShenZhen518057China

High-entropy ceramics(HECs)have shown great application potential under demanding conditions,such as high stresses and temperatures.However,the immense phase space poses great challenges for the rational design of new high-performance HECs.In this work,we develop machine-learning(ML)models to discover high-entropy ceramic carbides(HECCs).Built upon attributes of HECCs and their constituent precursors,our ML models demonstrate a high prediction accuracy(0.982).Using the well-trained ML models,we evaluate the single-phase probability of 90 HECCs that are not experimentally reported so far.Several of these predictions are validated by our experiments.We further establish the phase diagrams for non-equiatomic HECCs spanning the whole composition space by which the single-phase regime can be easily identified.Our ML models can predict both equiatomic and non-equiatomic HECs based solely on the chemical descriptors of constituent transition-metal-carbide precursors,which paves the way for the high-throughput design of HECCs with superior properties.

关键词： ceramics properties ceramic

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Multiferroic properties of Bi_(5.75)R_(0.25)Fe_(1.4)Ni_(0.6)Ti_(3)O_(18)(R=Eu,Sm,Nd,Bi and La)ceramics

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Journal of Rare Earths 2022年第1期40卷 112-117页

作者： Yongjie Yin Fei Liu Xiangyu Mao Wei Wang College of Physical Science and Technology Yangzhou UniversityYangzhou 225002China

An improved technique was used to prepare the ceramic samples of Bi_(5.75)R_(0.25)Fe_(1.4)Ni_(0.6)Ti_(3)O_(18)(BRFNT,R=Eu,Sm,Nd,Bi,and La).The five-layer Aurivillius phase of the samples was confirmed by X-ray diffraction(XRD)without detectable impurities.BRFNT samples exhibit the pseudo-tetragonal except the orthorhombic BSmFNT samples.The characteristic plate-like morphology was revealed by field emission transmission electron microscopy(FETEM)images.At ambient tempe rature,all the samples present both ferroelectric and magnetic properties and BEuFNT shows the best ferroelectric behavior with its remanent polarization as high as 14.9μC/cm^(2)under 155 kV/cm,which is three times higher than that of Bi_(5.75)R_(0.25)Fe_(1.4)Ni_(0.6)Ti_(3)O_(18).Moreover,the remanent magnetization of BEuFNT is increased up to 1.20 emu/g compared to that of Bi_(5.75)R_(0.25)Fe_(1.4)Ni_(0.6)Ti_(3)O_(18)which is only 0.53 emu/g.With increasing radius of the introduced A-site ions,the ferroelectric phase transition temperature(T_(CE))is decreased while the magnetic phase transition temperature(T_(CM))fluctuates.The decrease in both T_(CE)and T_(CM) corresponds to the upward shift of the related Raman modes and vice versa,indicating that the T_(CE)and the T_(CM) depend not only on the t factor,but also on the strength of the covalent bonds.

关键词： ceramics Multiferroics Phase transition temperature Rare earths Structure phase

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Structure,far-infrared spectroscopy,microwave dielectric properties,and improved low-temperature sintering characteristics of tri-rutile Mg_(0.5)Ti_(0.5)TaO_(4) ceramics

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Journal of Advanced ceramics 2023年第2期12卷 296-308页

作者： Hongyu YANG Liang CHAI Guangchao LIANG Mengjiang XING Zixuan FANG Xing ZHANG Tianying QIN Enzhu LI Academy of Advanced Interdisciplinary Research Xidian UniversityXi’an 710071China National Engineering Research Center of Electromagnetic Radiation Control Materials University of Electronic Science and Technology of ChinaChengdu 610054China Key Laboratory of Multi-Spectral Absorbing Materials and Structures of Ministry of Education University of Electronic Science and Technology of ChinaChengdu 610054China Yangtze Delta Region Institute(Huzhou) University of Electronic Science and Technology of ChinaHuzhou 313001China School of Materials and Energy University of Electronic Science and Technology of ChinaChengdu 611731China Sichuan Province Key Laboratory of Information Materials and Devices Application Chengdu University of Information TechnologyChengdu 610225China

In this study,tri-rutile type Mg_(0.5)Ti_(0.5)TaO_(4) ceramics were synthesized,where the structure–property relationship,especially the structural configuration and intrinsic dielectric origin of Mg_(0.5)Ti_(0.5)TaO_(4) ceramics,and the low-firing characteristics were studied.It is found that the tri-rutile structural type is unambiguously identified through the Rietveld refinement analysis,the selected area electron diffraction(SAED),and the high-resolution transmission electron microscopy(HRTEM)along the[110]zone axis.With the increase in sintering temperature,the densification and uniformity of crystal growth play important roles in regulating the microwave dielectric properties of Mg_(0.5)Ti_(0.5)TaO_(4) ceramics.Intrinsically,theoretical dielectric properties calculated by the far-infrared reflective spectra approached the experimental values,indicating the importance of structural features to dielectric properties.Furthermore,a glass additive with high matching relevance with ceramics has been developed to decrease the high sintering temperature of Mg_(0.5)Ti_(0.5)TaO_(4) ceramics,where 2–4 wt%Li_(2)O–MgO–ZnO–B_(2)O_(3)–SiO_(2)(LMZBS)glass frit was adopted to reduce the suitable temperature from 1275 to 1050℃ without significantly deteriorating the microwave dielectric characteristics.Specifically,Mg_(0.5)Ti_(0.5)TaO_(4) ceramics containing 2 wt% glass addition sintered at 1050℃for 4 h possess excellent microwave dielectric properties:dielectric constant(ε_(r))=44.3,quality factor multiplied by resonant frequency(Q×f)=23,820 GHz(f=6.2 GHz),and the temperature coefficient of resonant frequency(τ_(f))=123.2 ppm/℃.

关键词： Mg0.5Ti0.5TaO4 ceramics crystal structure low-temperature sintering

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An interpretable machine learning strategy for pursuing high piezoelectric coefficients in (K_(0.5)Na_(0.5))NbO_(3)-based ceramics

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npj Computational Materials 2023年第1期9卷 1-11页

作者： Bowen Ma Xiao Wu Chunlin Zhao Cong Lin Min Gao Baisheng Sa Zhimei Sun College of Materials Science and Engineering Fuzhou UniversityFuzhou 350108China School of Materials Science and Engineering Beihang UniversityBeijing 100191China

Perovskite-type lead-free piezoelectric ceramics allow access to illustrious piezoelectric coefficients(d33)through intricate composition design and experimental modulation.Developing a swift and accurate technology for identifying(K,Na)NbO_(3)(KNN)-based ceramic compositions with high d33 in exceedingly large“compositional”space will establish an innovative research paradigm surpassing the traditional empirical trial-and-error method.Herein,we demonstrate an interpretable machine learning(ML)framework for quick evaluation of KNN-based ceramics with high d33 based on data from published literature.Specifically,a thorough feature construction was carried out from the global and local dimensions to establish tree regression models with d33 as the target property.Subsequently,the feature-property mapping rules of KNN-based piezoelectric ceramics are further optimized through feature screening.To intuitively understand the correlation mechanisms between ML regression targets and features,the sure independence screening and sparsifying operator(SISSO)method was employed to extract the essential descriptors to explain d33.A straightforward descriptor,e^((NMB-MVB))·ST=(IDA)^(2),consisting of only four easily accessible parameters,can accelerate the evaluation of a series of novel KNN-based ceramics with high d33 while exhibiting strong theoretical interpretability.This work not only provides a tool for the rapid discovery of high piezoelectric performance in KNN-based ceramics but also offers a data-driven route for the design of property descriptors in perovskites.

关键词： ceramics ceramic piezoelectric

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High‐performance ZnO varistor ceramics prepared by arc‐induced flash sintering with low energy consumption at room temperature

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High Voltage 2022年第2期7卷 222-232页

作者： Angxuan Wu Zhixiang Zhu Xilin Wang Nianping Yan Hongyang Zhou Rongxia Huang Guoming Ma Zhidong Jia Liming Wang Engineering Laboratory of Power Equipment Reliability in Complicated Coastal Environments Tsinghua Shenzhen International Graduate SchoolTsinghua UniversityShenzhenGuangdongChina State Key Laboratory of Advanced Power Transmission Technology Global Energy Interconnection Research Institute Co.LtdBeijingChina State Grade Jiangxi Electric Power Research Institute NanchangChina School of Electromechanical Engineering Guangdong University of TechnologyGuangzhouGuangdongChina State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijingChina

The development of ultra‐high voltage transmission lines requires a ZnO arrester with excellent electrical response and high voltage gradient.Compared with conventional preparation methods,flash sintering allows fast production of novel high‐performance ZnO varistor ceramics with low energy consumption and controlled grain growth.Herein,ZnO varistor ceramics were prepared using the flash sintering method at an air pressure of 21 kPa for 60 s at 25℃.The results showed that the flash‐sintered samples had fine grains and reduced loss of volatile elements.Moreover,the voltage gradient,leakage current density,and non‐linear coefficient of the flash‐sintered varistor ceramics were significantly improved compared with those of conventionally sintered samples.Owing to the short preparation time and absence of a heating process,the energy consumption of the proposed flash sintering method was significantly reduced to 10%of that by conventional sintering.The proposed method is a promising approach for the preparation of ZnO arresters with excellent electrical properties and serves as an effective method that realises energy saving and emission reduction.

关键词： ceramics varistor preparation

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Effects of Sm Doping to Improve the Thermoelectric Properties of ZnO ceramics

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Journal of Wuhan University of Technology(Materials Science) 2022年第6期37卷 1166-1171页

作者：冯波 MAO Wentao School of Mechanical and Electrical Engineering Wuhan Donghu UniversityWuhan 430070China Institute of Engineering and Technology Hubei University of Science and TechnologyXianning 437100China

A series of Sm doped ZnO based thermoelectric materials were prepared by mechanical alloying and spark plasma sintering.The effects of Sm doping on ZnO based thermoelectric materials were systematically studied by means of electrical and thermal properties tests combined with first principles calculations of energy band,density of states and elastic constants.The experimental results show that the substitution of Sm at Zn site could cause the valence band and conduction band moving down,and the 4f orbitals of Sm could contribute to the increase of the density of states near the Fermi level,corresponding to the increase of carrier concentration and electrical conductivity.The substitution of Sm at Zn site could cause the decrease of effective mass and Seebeck coefficient.The substitution of Sm at Zn site could lead to the decrease of Young's modulus and lattice thermal conductivity,which contribute to the decrease of thermal conductivity.Finally,the highest dimensionless thermoelectric figure of merit(ZT)value has been increased to 0.346,which is 3.48 times as pristine ZnO.

关键词： Sm doping energy band engineering phonons ceramics

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Progress in Research on Structural Ceramic Materials Toughened by Graphene

Expert Review of Chinese Chemical

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Expert Review of Chinese Chemical 2024年第2期2卷 37-42页

作者： Wenyu Yao Yalong Zhang College of Materials Science and Engineering Shenyang University of Architecture

Graphene has excellent mechanical properties and unique physical/chemical properties,which make it have a good strengthening and toughening effect on structural ceramic materials.In recent years,it has received widespread attention and research.This article reviews the mixing and sintering processes in the preparation of graphene/ceramic com-posites,as well as the toughening mechanism of graphene on ceramic materials.It also looks forward to how to further enhance the toughening effect of graphene.

关键词： graphene ceramics mixing materials sintering toughening

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Structure and dielectric properties of (1-x)Na_(0.5)Bi_(0.5)TiO_(3-x)Na_(0.5)K_(0.5)NbO_(3)

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Journal of Advanced Dielectrics 2024年第1期14卷 82-88页

作者： E.V.Glazunova L.A.Shilkina A.S.Chekhova A.V.Nazarenko I.A.Verbenko L.A.Reznichenko Research Institute of Physics Southern Federal University Rostov-on-Don344090Russia Faculty of Physics Southern Federal University Rostov-on-Don344090Russia Southern Scientific Center of the Russian Academy of Sciences Rostov-on-Don 344006Russia

The solid solutions of the(1-x)Na_(0.5)Bi_(0.5)TiO_(3-x)Na_(0.5)K_(0.5)NbO_(3) system were produced by the conventional ceramic technology using mechanical activation of the synthesized product.It was found that in the(1-x)Na_(0.5)Bi_(0.5)TiO_(3-x)Na_(0.5)K_(0.5)NbO_(3) system at room temperature,a number of morphotropic phase transitions occur:rhombohedral!cubic!tetragonal!monoclinic phases.The introduction of a small amount of Na_(0.5)K_(0.5)NbO_(3) leads to an increase in the temperature stability of the dielectric properties of ceramics.A change in the relaxor properties of the solid solutions of the(1-x)Na_(0.5)Bi_(0.5)TiO_(3-x)Na_(0.5)K_(0.5)NbO_(3) system was shown.The increase in energy density and energy efficiency was found at additive 10 mol.%of Na_(0.5)K_(0.5)NbO_(3).

关键词： ceramics lead-free materials mechanical activation dielectric properties energy storage

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