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Robust and Tunable Ferroelectricity in Ba/Co Codoped (K_(0.5)Na_(0.5))NbO_(3) Ceramics
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作者 刘佳讯 查节林 +5 位作者 杨玉龙 吕笑梅 胡雪莉 阎朔 吴子敬 黄凤珍 《Chinese Physics Letters》 SCIE EI CAS CSCD 2024年第7期152-160,共9页
The 0.98(K_(0.5)Na_(0.5))NbO_(3)-0.02Ba(Nb_(0.5)Co_(0.5))O_(3-δ) ceramics with doped Ba^(2+) and Co^(2+) ions are fabricated,and the impacts of the thermal process are studied.Compared with the rapidly cooled (RC) sa... The 0.98(K_(0.5)Na_(0.5))NbO_(3)-0.02Ba(Nb_(0.5)Co_(0.5))O_(3-δ) ceramics with doped Ba^(2+) and Co^(2+) ions are fabricated,and the impacts of the thermal process are studied.Compared with the rapidly cooled (RC) sample,the slowly cooled (SC) sample possesses superior dielectric and ferroelectric properties,and an 11 K higher ferroelectricparaelectric phase transition temperature,which can be attributed to the structural characteristics such as the grain size and the degree of anisotropy.Heat treatment can reversibly modulate the content of the oxygen vacancies,and in turn the ferroelectric hysteresis loops of the samples.Finally,robust and tunable ferroelectric property is achieved in SC samples with good structural integrity. 展开更多
关键词 ceramics FERROELECTRIC treatment
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Temperature/electric field induced photoluminescence-modulation effect in dysprosium-doped barium titanate ferroelectric ceramics
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作者 Lei Xia Xiao Liu +4 位作者 Zhan Mao Yanbin Cai Jing Zhu Jiyang Xie Wanbiao Hu 《Journal of Materiomics》 SCIE CSCD 2024年第5期1117-1125,共9页
Lanthanide(Ln^(3+))based ferroelectric phosphors,with an integration of PL emission and ferroelectric effect,are unveiling an exciting realm of possibilities for multifunctional ferroelectric-optic materials.However,h... Lanthanide(Ln^(3+))based ferroelectric phosphors,with an integration of PL emission and ferroelectric effect,are unveiling an exciting realm of possibilities for multifunctional ferroelectric-optic materials.However,how the ferroelectric host enables the tuning on the PL emissions through modulating the local structure(e.g.,lattice site,symmetry,strains etc.)of the Ln^(3+)activator is not established yet.In this work,a luminescent-ferroelectric material,i.e.Dy^(3+)doped BaTiO_(3) ceramic(Ba_(1–x)Dy_(x)TiO_(3)(x=0–0.07),abbr:BTO:Dy^(3+)),was explored to address the aforementioned issues.The BTO:Dy^(3+)ceramics were synthesized by a solid-state reaction method.The crystal structure,photoluminescence(PL)and electric properties(dielectric constant,ferroelectric hysteresis and piezoelectric hysteresis loop)were systematically investigated.The BTO:Dy^(3+)ceramics show two predominant emission peaks,corresponding to the blue magnetic dipole transition(477 nm,4F_(7/2)→6H_(15/2))and yellow electric dipole transition(573 nm,4F_(7/2)→6H_(13/2)),the intensity ration of which can be modulated by the ferroelectric polarization that causes the slight lattice deformation.Such a polarization-emission modulation combining with the Dy3+doping could accelerate the color change,from yellow to blue,which is characterized to detect the phase transition,with a method and mechanism were proposed,that is,the phase change is reflected by the PL characteristic peak intensity ratio.Therefore,the current results offer a convenient photoluminescence method for detecting the ferroelectric phase transition and a feasible approach to study the interaction between the photoluminescence and polarization in ferroelectric materials,for providing new insights for the development of multifunctional materials. 展开更多
关键词 PHOTOLUMINESCENCE Barium titanate MODULATION Ferroelectric ceramics
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Anomalous photovoltaic effect in Na_(0.5)Bi_(0.5)TiO_(3)-based ferroelectric ceramics based on domain engineering
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作者 Xinxiang Yang Xing Gao +7 位作者 Shan Zhang Jun Zhao Xinlei Zhang Xin Song Chunxiao Lu Yong Li Liwen Zhang Xihong Hao 《Journal of Materiomics》 SCIE CSCD 2024年第5期975-983,共9页
The anomalous photovoltaic(APV)effect is promising for high-performance ferroelectric materials and devices in photoelectric applications.However,it is a challenge how to tune the APV effect by utilizing the character... The anomalous photovoltaic(APV)effect is promising for high-performance ferroelectric materials and devices in photoelectric applications.However,it is a challenge how to tune the APV effect by utilizing the characteristic structure of ferroelectrics.Here,a domain engineering strategy is proposed to enhance the APV effect in lead-free 0.88(Na_(0.5)Bi_(0.5)TiO_(3))-0.12(Ba_(1–1.5x)S_(mx)TiO_(3))(NBT-BST)ferroelectric ceramics.By tuning the domain size based on Sm^(3+)doping,a maximum open-circuit voltage(VOC)of 18.1 V is obtained when Sm^(3+)content is 0.75%,which is much larger than its bandgap(Eg).The mechanism of this large VOC originates from the multiple positive effects induced by the small-size domain,where decreasing domain size enhances ferroelectric polarization and net interface barrier potential,leading to a large driving electric field.Moreover,the APV effect exhibits a giant temperature sensitivity due to the dramatic evolution of small-size domain in the temperature field.This work sheds light on the exploration of ferroelectrics with APV effect and inspires their future high-performance optoelectronic device applications. 展开更多
关键词 Anomalous photovoltaic effect FERROELECTRIC Domain NBT-BST ceramics Polarization
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Improving high-field strain and temperature stability on KNN-based ceramics sintered in reducing atmosphere via defect engineering
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作者 Zhenyong Cen Meiyi Feng +5 位作者 Fuzhi Cao Yuqi Jiang Ze Xu Changrong Zhou Ke Wang Nengneng Luo 《Journal of Materiomics》 SCIE CSCD 2024年第6期1165-1175,共11页
High-field strain and its temperature stability of(1-x)K_(0.48)Na_(0.52)Nb_(0.96)Ta_(0.04)O_(3)-xBaZrO_(3)+8%MnO+3%ZrO_(2)(in mole,KNNT-xBZ+8Mn)ceramics sintered in reducing atmosphere are improved simultaneously via ... High-field strain and its temperature stability of(1-x)K_(0.48)Na_(0.52)Nb_(0.96)Ta_(0.04)O_(3)-xBaZrO_(3)+8%MnO+3%ZrO_(2)(in mole,KNNT-xBZ+8Mn)ceramics sintered in reducing atmosphere are improved simultaneously via defect design in A and B site.There is a conducting type transition from n-type to p-type at x=0.07.The BaZrO_(3) dopant not only induces the increase of defects(Zr′_(Nb),Ba_(Na),Ba_(K))concentration,but also results in the increase of defect(Mn″_(Nb))concentration,because more Mn ions as+2 oxidation state in ceramics is triggered by BaZrO3 doping modifcation.Defect dipoles(Mn″_(Nb)-V_(o),Zr′_(Nb)-V_(o),Ba_(Na)-V′_(Na),Ba_(Na)-V′_(Na))in poled and aged ceramics enhance the reversibility of the non-180°domains switching,which increases the high-field strain of KNNT-xBZ+8Mn ceramics.The reversibility of non-180°domain switching can be preserved to high temperature due to stable defect dipoles(Ba_(Na)-V′_(Na),Ba_(K)-V′_(K))in A-site.The KNNT-xBZ+8Mn ceramics at x=0.07 show the largest high-field strain coefficient(543 pm/V@20 kV/cm)and the highest temperature stability(125℃).The KNNT-xBZ+8Mn ceramic is a lead-free material with great potential to be applied in the fabrication of multilayer ceramic actuators with Ni inner electrodes in the future. 展开更多
关键词 Lead-free ceramics Piezoelectric materials Reducing atmosphere DEFECTS
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Preparation and Photostriction Properties of BiFeO_(3)-BaTiO_(3)Ceramics
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作者 ZHENG Zewei ZHANG Liqiang +3 位作者 CHEN Chen CAO Minghe YI Zhiguo LIU Hanxing 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第5期1079-1086,共8页
Under illumination by 405,520 and 655 nm monochromatic visible light(light intensity of 30 kW/m^(2)),large photostriction(ΔL/L)of 0.19%,0.13%and 0.26%for 67BiFeO_(3)-33BaTiO_(3)(67BF-33BT)lead-free ferroelectric cera... Under illumination by 405,520 and 655 nm monochromatic visible light(light intensity of 30 kW/m^(2)),large photostriction(ΔL/L)of 0.19%,0.13%and 0.26%for 67BiFeO_(3)-33BaTiO_(3)(67BF-33BT)lead-free ferroelectric ceramics are obtained,respectively.By studying the ferroelectric and photoelectric properties in conjunction with in situ Raman spectroscopy,it is found that the photostrictive effect of 67BF-33BT is not caused by the electrical strain induced by abnormal photovoltaic voltage,but related to the optical induced oxygen octahedral distortion.The 67BF-33BT lead-free ferroelectric material with excellent photostrictive response in the visible light region is expected to play an important role in the field of optical drive electromechanical devices. 展开更多
关键词 ferroelectric ceramics photostrictive effect visible light response
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Microstructure Characteristics and Possible Phase Evolution of the Coal Gangue-Steel Slag Ceramics Prepared by the Solid-State Reaction Methods
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作者 刘文洁 WANG Yang +1 位作者 LI Jingtao 李宝让 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第4期921-930,共10页
Industrial wastes such as steel slag and coal gangue etc.were chosen as raw materials for preparing ceramic via the conventional solid-state reaction method.With steel slag and coal gangue mixed in various mass ratios... Industrial wastes such as steel slag and coal gangue etc.were chosen as raw materials for preparing ceramic via the conventional solid-state reaction method.With steel slag and coal gangue mixed in various mass ratios,from 100%steel slag to 100%coal gangue at 10%intervals,microstructure and possible phase evolution of the coal gangue-steel slag ceramics were investigated using X-ray powder diffraction,scanning electron microscopy,mercury intrusion porosimetry and Archimedes boiling method.The experimental results suggest that the phase compositions of the as-prepared ceramics could be altered with the increased amount of coal gangue in the ceramics.The anorthite-diopside eutectic can be formed in the ceramics with the mass ratios of steel slag to coal gangue arranged from 8:2 to 2:8,which was responsible for the melting of the steel slag-coal gangue ceramics at relatively high temperature.Further investigations on the microstructure suggested that the addition of the proper amount of steel slag in ceramic compositions was conducive to the pore formation and further contributed to an increment in porosity. 展开更多
关键词 steel slag-coal gangue ceramics SYNTHESIS phase evolution microstructure characteristics
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A critical review of direct laser additive manufacturing ceramics
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作者 Dake Zhao Guijun Bi +4 位作者 Jie Chen WaiMeng Quach Ran Feng Antti Salminen Fangyong Niu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第12期2607-2626,共20页
The urgent need for integrated molding and sintering across various industries has inspired the development of additive manu-facturing(AM)ceramics.Among the different AM technologies,direct laser additive manufacturin... The urgent need for integrated molding and sintering across various industries has inspired the development of additive manu-facturing(AM)ceramics.Among the different AM technologies,direct laser additive manufacturing(DLAM)stands out as a group of highly promising technology for flexibly manufacturing ceramics without molds and adhesives in a single step.Over the last decade,sig-nificant and encouraging progress has been accomplished in DLAM of high-performance ceramics,including Al_(2)O_(3),ZrO_(2),Al_(2)O_(3)/ZrO_(2),SiC,and others.However,high-performance ceramics fabricated by DLAM face challenges such as formation of pores and cracks and resultant low mechanical properties,hindering their practical application in high-end equipment.Further improvements are necessary be-fore they can be widely adopted.Methods such as field-assisted techniques and post-processing can be employed to address these chal-lenges,but a more systematic review is needed.This work aims to critically review the advancements in direct selective laser sintering/melting(SLS/SLM)and laser directed energy deposition(LDED)for various ceramic material systems.Additionally,it provides an overview of the current challenges,future research opportunities,and potential applications associated with DLAM of high-perform-ance ceramics. 展开更多
关键词 3D printing laser additive manufacturing ceramics QUALITY microstructure mechanical properties
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Si/Al order and texture orientation optimization of red-emitting Mg_(2)Al_(4)Si_(5)O_(18):Eu^(2+)ceramics for laser phosphor display
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作者 Weibin Chen Yuzhen Wang +2 位作者 Gaochao Liu Yongsheng Sun Zhiguo Xia 《Journal of Materiomics》 SCIE CSCD 2024年第5期1137-1143,共7页
Laser phosphor display technology plays an important role in advanced display projection;however,it is a challenge in maintaining excellent color accuracy under high brightness due to the lack of red spectrum.Here,red... Laser phosphor display technology plays an important role in advanced display projection;however,it is a challenge in maintaining excellent color accuracy under high brightness due to the lack of red spectrum.Here,red-emitting Mg_(2)Al_(4)Si_(5)O_(18):Eu^(2+)ceramics as the phosphor wheel have been optimized in chemical compositions and texture orientation.The textured Mg_(2)Al_(4)Si_(5)O_(18):Eu^(2+)ceramics have high transparency and spot limiting ability,accordingly,the ceramic wheel outputs 1,184 lm of ultra-bright red light under 50 W/mm^(2) laser power density.Moreover,the red spectral utilization(over 600 nm)of textured Mg_(2)Al_(4)Si_(5)O_(18):Eu^(2+)ceramics is 2.17 times that of traditional Y3Al5O12:Ce^(3+)phosphor wheel.The red-emitting textured Mg_(2)Al_(4)Si_(5)O_(18):Eu^(2+)cordierite ceramic herein enables an improved light-color saturation experience,and it is potential in the next-generation laser phosphor display applications. 展开更多
关键词 Luminescent materials Rare earth materials Textured ceramic Red emission Laser phosphor display
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Microstructure and Oxidation Behavior of ZrB_(2)-SiC Ceramics Fabricated by Tape Casting and Reactive Melt Infiltration
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作者 TAN Min CHEN Xiaowu +5 位作者 YANG Jinshan ZHANG Xiangyu KAN Yanmei ZHOU Haijun XUE Yudong DONG Shaoming 《无机材料学报》 SCIE EI CAS CSCD 北大核心 2024年第8期955-964,共10页
ZrB_(2)-based ceramics typically necessitate high temperature and pressure for sintering,whereas ZrB_(2)-SiC ceramics can be fabricated at 1500℃using the process of reactive melt infiltration with Si.In comparison to... ZrB_(2)-based ceramics typically necessitate high temperature and pressure for sintering,whereas ZrB_(2)-SiC ceramics can be fabricated at 1500℃using the process of reactive melt infiltration with Si.In comparison to the conventional preparation method,reactive synthesis allows for the more facile production of ultra-high temperature ceramics with fine particle size and homogeneous composition.In this work,ZrSi_(2),B4C,and C were used as raw materials to prepare ZrB_(2)-SiC via combination of tape casting and reactive melt infiltration herein referred to as ZBC ceramics.Control sample of ZrB_(2)-SiC was also prepared using ZrB_(2) and SiC as raw materials through an identical process designated as ZS ceramics.Microscopic analysis of both ceramic groups revealed smaller and more uniformly distributed particles of the ZrB_(2) phase in ZBC ceramics compared to the larger particles in ZS ceramics.Both sets of ceramics underwent cyclic oxidation testing in the air at 1600℃for a cumulative duration of 5 cycles,each cycle lasting 2 h.Analysis of the oxidation behavior showed that both ZBC ceramics and ZS ceramics developed a glassy SiO_(2)-ZrO_(2) oxide layer on their surfaces during the oxidation.This layer severed as a barrier against oxygen.In ZBC ceramics,ZrO_(2) is finely distributed in SiO_(2),whereas in ZS ceramics,larger ZrO_(2) particles coexist with glassy SiO_(2).The surface oxide layer of ZBC ceramics maintains a dense structure because the well-dispersed ZrO_(2) increases the viscosity of glassy SiO_(2),preventing its crystallization during the cooling.Conversely,some SiO_(2) in the oxide layer of ZS ceramics may crystallize and form a eutectic with ZrO_(2),leading to the formation of ZrSiO_(4).This leads to cracking of the oxide layer due to differences in thermal expansion coefficients,weakening its barrier effect.An analysis of the oxidation resistance shows that ZBC ceramics exhibit less increase in oxide layer thickness and mass compared to ZS ceramics,suggesting superior oxidation resistance of ZBC ceramics. 展开更多
关键词 ultra-high temperature ceramic ZRB2-SIC oxidation behavior reactive melt infiltration
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Low-firing and temperature stability regulation of tri-rutile MgTa_(2)O_(6)microwave dielectric ceramics
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作者 Chengzhi Xu Hongyu Yang +5 位作者 Hongcheng Yang Linzhuang Xing Yuan Wang Zhimin Li Enzhu Li Guorui Zhao 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第8期1935-1943,共9页
A glass frit containing Li_(2)O-MgO-ZnO-B_(2)O_(3)-SiO_(2)component was used to explore the low-temperature sintering behaviors and microwave dielectric characteristics of tri-rutile MgTa_(2)O_(6)ceramics in this stud... A glass frit containing Li_(2)O-MgO-ZnO-B_(2)O_(3)-SiO_(2)component was used to explore the low-temperature sintering behaviors and microwave dielectric characteristics of tri-rutile MgTa_(2)O_(6)ceramics in this study.The good low-firing effects are presented due to the high matching relevance between Li_(2)O-MgO-ZnO-B_(2)O_(3)-SiO_(2)glass and MgTa_(2)O_(6)ceramics.The pure tri-rutile MgTa_(2)O_(6)structure remains unchanged,and high sintering compactness can also be achieved at 1150℃.We found that the Li_(2)O-MgO-ZnO-B_(2)O_(3)-SiO_(2)glass not only greatly improves the low-temperature sintering characteristics of MgTa_(2)O_(6)ceramics but also maintains a high(quality factor(Q)×resonance frequency(f))value while still improving the temperature stability.Typically,great microwave dielectric characteristics when added with 2wt%Li_(2)O-MgO-ZnO-B_(2)O_(3)-SiO_(2)glass can be achieved at 1150℃:dielectric constant,ε_(r)=26.1;Q×f=34267 GHz;temperature coefficient of resonance frequency,τ_(f)=-8.7×10^(-6)/℃. 展开更多
关键词 MgTa_(2)O_(6) ceramIC microwave dielectric characteristics glass
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Clay Materials for Ceramics Application from N’Djamena in the Chad Republic: Mineralogical, Physicochemical and Microstructural Characterization
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作者 Ndjolba Madjihingam Djoda Pagore +3 位作者 Jacques Richard Mache Bebbata Warabi Bertin Pagna Kagonbe Patrick Mountapmbeme Kouotou 《Journal of Materials Science and Chemical Engineering》 2024年第2期31-48,共18页
Herein, we report some characteristics of the clayey materials (CMs) collected from Kaliwa (C1), Kabé (C2) and Malo (C3) district in N’Djamena (Chad). Three samples were characterized applying XRF, XRD, FTIR, SE... Herein, we report some characteristics of the clayey materials (CMs) collected from Kaliwa (C1), Kabé (C2) and Malo (C3) district in N’Djamena (Chad). Three samples were characterized applying XRF, XRD, FTIR, SEM. In addition, TGA/DSC were performed to control decomposition/mass loss and show phase transitions respectively of CMs. Geochemical analysis by XRF reveals the following minerals composition: SiO<sub>2</sub> (~57% - 66%), Al<sub>2</sub>O<sub>3 </sub>(~13% - 15%), Fe<sub>2</sub>O<sub>3</sub> (~6% - 10%), TiO<sub>2</sub> (~1% - 2%) were the predominant oxides with a reduced proportion in C1, and (~7%) of fluxing agents (K<sub>2</sub>O, CaO, Na<sub>2</sub>O). Negligible and trace of MgO (~1%) and P<sub>2</sub>O<sub>5</sub> was noted. The mineralogical composition by XRD shows that, C1, C2 and C3 display close mineralogy with: Quartz (~50%), feldspar (~20%) as non-clay minerals, whereas clays minerals were mostly kaolinite (~15%), illite (~5%) and smectite (~10%). FTIR analysis exhibits almost seemingly similar absorption bands characteristic of hydroxyls elongation, OH valence vibration of Kaolinite and stretching vibration of some Metal-Oxygen bond. SEM micrographs of the samples exhibit microstructureformed by inter-aggregates particles with porous cavities. TGA/DSCconfirm the existence of quartz (570˚C to 870˚C), carbonates (600˚C - 760˚C), kaolinite (569˚C - 988˚C), illite (566˚C - 966˚C), MgO (410˚C - 720˚C) and smectite (650˚C - 900˚C). The overall characterization indicates that, these clayey soils exhibit good properties for ceramic application. 展开更多
关键词 Clay Soils Characterization MINERALOGY Physicochemical Properties ceramic Application
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Study on Acoustic Emission Characteristics of Deformation Damage Process of Zirconia Ceramics
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作者 Qingchuan Fu Yushu Lai 《Journal of Materials Science and Chemical Engineering》 2024年第2期61-72,共12页
Zirconia ceramics have become increasingly widely used in recent years and are favored by relevant enterprises. From the traditional dental field to aerospace, parts manufacturing has been used, but there is limited r... Zirconia ceramics have become increasingly widely used in recent years and are favored by relevant enterprises. From the traditional dental field to aerospace, parts manufacturing has been used, but there is limited research on the deformation and damage process of zirconia ceramics. This article analyzes the acoustic emission characteristics of each stage of ceramic damage from the perspective of acoustic emission, and explores its deformation process characteristics from multiple perspectives such as time domain, frequency, and EWT modal analysis. It is concluded that zirconia ceramics exhibit higher brittleness and acoustic emission strength than alumina ceramics, and when approaching the fracture, it tends to generate lower frequency acoustic emission signals. 展开更多
关键词 Zirconia ceramics Acoustic Emission Monitoring Crack Damage
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The B-site ordering in RFe_(0.5)Cr_(0.5)O_(3)ceramics and its effect on magnetic properties
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作者 Li Hou Lei Shi +3 位作者 Liping Yang Yiqiang Liu Zhitao Li Lanxiang Meng 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第10期434-441,共8页
To insight into the B-site ordering in RFe_(0.5)Cr_(0.5)O_(3)ceramics,a series of RFe_(0.5)Cr_(0.5)O_(3)ceramics(R=La,Y,Lu)were synthesized by the sol-gel method,and the structural and magnetic properties were systemi... To insight into the B-site ordering in RFe_(0.5)Cr_(0.5)O_(3)ceramics,a series of RFe_(0.5)Cr_(0.5)O_(3)ceramics(R=La,Y,Lu)were synthesized by the sol-gel method,and the structural and magnetic properties were systemically investigated.By using the Rietveld refinement of all samples,it is found that the structural distortion is increased as the R ionic radius decreases,leading to the weakened interactions between Fe/Cr ions.Moreover,the Fe and Cr are arranged in disorder in LaFe_(0.5)Cr_(0.5)O_(3),but partially ordered in YFe_(0.5)Cr_(0.5)O_(3)and LuFe_(0.5)Cr_(0.5)O_(3),showing an increasing trend of the proportion of ordered domains with the decrease of R ionic radius.Through fitting the temperature-dependent magnetizations,it is identified that the magnetization reversal(MR)in disorder LaFe_(0.5)Cr_(0.5)O_(3)is resulted from the competition between the moments of Cr and Fe sublattices.In the partially ordered YFe_(0.5)Cr_(0.5)O_(3)and LuFe_(0.5)Cr_(0.5)O_(3)ceramics,because of the presence of Fe-O-Cr networks in the ordered domains whose moment is antiparallel to that of Fe-O-Fe and Cr-O-Cr in the disordered domains,the compensation temperature T_(comp)of MR is increased by nearly 50 K.These results suggest that the changing of R-site ions could be used very effectively to modify the Fe-O-Cr ordering,apart from the structural distortion,which has a direct effect on the magnetic exchange interactions in RFe_(0.5)Cr_(0.5)O_(3)ceramics.Then at values of composition where ordered domains are expected to be larger in number as compared to disordered domains and with a weaker structural distortion,one can expect a higher transition temperature Tcomp,providing a different view for adjustment of the magnetic properties of RFe_(0.5)Cr_(0.5)O_(3)ceramics for practical applications. 展开更多
关键词 RFe_(0.5)Cr_(0.5)O_(3)ceramics structural distortion B-site ordering magnetization reversal
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Physics-embedded machine learning search for Sm-doped PMN-PT piezoelectric ceramics with high performance
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作者 辛睿 王亚祺 +6 位作者 房泽 郑凤基 高雯 付大石 史国庆 刘建一 张永成 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第8期81-88,共8页
Pb(Mg_(1/3)Nb_(2/3))O_(3)–PbTiO_(3)(PMN-PT)piezoelectric ceramics have excellent piezoelectric properties and are used in a wide range of applications.Adjusting the solid solution ratios of PMN/PT and different conce... Pb(Mg_(1/3)Nb_(2/3))O_(3)–PbTiO_(3)(PMN-PT)piezoelectric ceramics have excellent piezoelectric properties and are used in a wide range of applications.Adjusting the solid solution ratios of PMN/PT and different concentrations of elemental doping are the main methods to modulate their piezoelectric coefficients.The combination of these controllable conditions leads to an exponential increase of possible compositions in ceramics,which makes it not easy to extend the sample data by additional experimental or theoretical calculations.In this paper,a physics-embedded machine learning method is proposed to overcome the difficulties in obtaining piezoelectric coefficients and Curie temperatures of Sm-doped PMN-PT ceramics with different components.In contrast to all-data-driven model,physics-embedded machine learning is able to learn nonlinear variation rules based on small datasets through potential correlation between ferroelectric properties.Based on the model outputs,the positions of morphotropic phase boundary(MPB)with different Sm doping amounts are explored.We also find the components with the best piezoelectric property and comprehensive performance.Moreover,we set up a database according to the obtained results,through which we can quickly find the optimal components of Sm-doped PMN-PT ceramics according to our specific needs. 展开更多
关键词 Pb(Mg_(1/3)Nb_(2/3))O_(3)–PbTiO_(3)(PMN-PT)ceramic physics-embedded machine learning piezoelectric coefficient Curie temperature
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Porous high-entropy rare-earth phosphate(REPO_(4),RE=La,Sm,Eu,Ce,Pr and Gd)ceramics with excellent thermal insulation performance via pore structure tailoring
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作者 Peixiong Zhang Enhui Wang +3 位作者 Jingjing Liu Tao Yang Hailong Wang Xinmei Hou 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第7期1651-1658,共8页
Thermal insulation materials play an increasingly important role in protecting mechanical parts functioning at high temperatures.In this study,a new porous high-entropy(La_(1/6)Ce_(1/6)Pr_(1/6)Sm_(1/6)Eu_(1/6)Gd_(1/6)... Thermal insulation materials play an increasingly important role in protecting mechanical parts functioning at high temperatures.In this study,a new porous high-entropy(La_(1/6)Ce_(1/6)Pr_(1/6)Sm_(1/6)Eu_(1/6)Gd_(1/6))PO_(4)(HE(6RE_(1/6))PO_(4))ceramics was prepared by combining the high-entropy method with the pore-forming agent method and the effect of different starch contents(0–60vol%)on this ceramic properties was systematically investigated.The results show that the porous HE(6RE_(1/6))PO_(4)ceramics with 60vol%starch exhibit the lowest thermal conductivity of 0.061 W·m^(-1)·K^(-1)at room temperature and good pore structure stability with a linear shrinkage of approximately1.67%.Moreover,the effect of large regular spherical pores(>10μm)on its thermal insulation performance was discussed,and an optimal thermal conductivity prediction model was screened.The superior properties of the prepared porous HE(6RE_(1/6))PO_(4)ceramics allow them to be promising insulation materials in the future. 展开更多
关键词 porous high-entropy(La_(1/6)Ce_(1/6)Pr_(1/6)Sm_(1/6)Eu_(1/6)Gd_(1/6))PO_(4) ceramics high-entropy strategy pore-forming agent method thermal insulation material thermal conductivity
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Effects of ZnO,FeO and Fe_(2)O_(3)on the spinel formation,microstructure and physicochemical properties of augite-based glass ceramics 被引量:2
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作者 Shuai Zhang Yanling Zhang Shaowen Wu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2023年第6期1207-1216,共10页
Augite-based glass ceramics were synthesised using ZnO,FeO,and Fe_(2)O_(3)as additives,and the spinel formation,matrix structure,crystallisation thermodynamics,and physicochemical properties were investigated.The resu... Augite-based glass ceramics were synthesised using ZnO,FeO,and Fe_(2)O_(3)as additives,and the spinel formation,matrix structure,crystallisation thermodynamics,and physicochemical properties were investigated.The results showed that oxides resulted in numerous preliminary spinels in the glass matrix.FeO,ZnO,and Fe_(2)O_(3)influenced the formation of spinel,while FeO simplified the glass network.FeO and ZnO promoted bulk crystallisation of the parent glass.After adding oxides,the grains of augite phase were refined,and the relative quantities of augite crystal planes were also influenced.All samples displayed good mechanical properties and chemical stability.The 2wt%ZnO-doping sample displayed the maximum flexural strength(170.3 MPa).Chromium leaching amount values of all the samples were less than the national standard(1.5 mg/L),confirming the safety of the materials.In conclusion,an appropriate amount of zinc-containing raw material is beneficial for the preparation of augite-based glass ceramics. 展开更多
关键词 SPINEL network structure thermodynamics MICROSTRUCTURE glass ceramics
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Improved microwave dielectric properties of MgAl_(2)O_(4)spinel ceramics through(Li_(1/3)Ti_(2/3))^(3+)doping 被引量:1
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作者 李潇 杨习志 +7 位作者 赖元明 张芹 李宝阳 戚聪 殷俊 王凡硕 巫崇胜 苏桦 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第5期668-673,共6页
A series of nominal compositions MgAl_(2-x)(Li_(1/3)Ti_(2/3))_(x)O_(4)(x=0,0.04,0.08,0.12,0.16,and 0.20)ceramics were successfully prepared via the conventional solid-state reaction route.The phase compositions,micros... A series of nominal compositions MgAl_(2-x)(Li_(1/3)Ti_(2/3))_(x)O_(4)(x=0,0.04,0.08,0.12,0.16,and 0.20)ceramics were successfully prepared via the conventional solid-state reaction route.The phase compositions,microstructures,and microwave dielectric properties were investigated.The results of x-ray diffraction(XRD)and scanning electron microscopy(SEM)showed that a single phase of MgAl_(2-x)(Li_(1/3)Ti_(2/3))_(x)O_(4)ceramics with a spinel structure was obtained at x≤0.12,whereas the second phase of MgTi_(2)O_(5)appeared when x>0.12.The cell parameters were obtained by XRD refinement.As the x values increased,the unit cell volume kept expanding.This phenomenon could be attributed to the partial substitution of(Li_(1/3)Ti_(2/3))^(3+)for Al^(3+).Results showed that(Li_(1/3)Ti_(2/3))^(3+)doping into MgAl_(2)O_(4)spinel ceramics effectively reduced the sintering temperature and improved the quality factor(Q_f)values.Good microwave dielectric properties were achieved for a sample at x=0.20 sintering at 1500℃in air for 4 h:dielectric constantε_(r)=8.78,temperature coefficient of resonant frequencyτ_(f)=-85 ppm/℃,and Q_(f)=62300 GHz.The Q_(f)value of the x=0.20 sample was about 2 times higher than that of pure MgAl_(2)O_(4)ceramics(31600 GHz).Thus,MgAl_(2-x)(Li_(1/3)Ti_(2/3))_(x)O_(4)ceramics with excellent microwave dielectric properties can be applied to 5G communications. 展开更多
关键词 microwave dielectric ceramics MgAl_(2)O_(4)ceramic co-substitution MgTi_(2)O_(5) solid solubility limit
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Preparation and Thermal Shock Resistance of Mullite Ceramics for High Temperature Solar Thermal Storage 被引量:1
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作者 吴建锋 章真宇 +3 位作者 XU Xiaohong MA Sitong LI Peixian SHI Xingxing 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2023年第4期743-752,共10页
Mullite thermal storage ceramics were prepared by low-cost calcined bauxite and kaolin.The phase composition,microstructure,high temperature resistance and thermophysical properties were characterized by modern testin... Mullite thermal storage ceramics were prepared by low-cost calcined bauxite and kaolin.The phase composition,microstructure,high temperature resistance and thermophysical properties were characterized by modern testing techniques.The experimental results indicate that sample A3(bauxite/kaolin ratio of 5:5)sintered at 1620℃has the optimum comprehensive properties,with bulk density of 2.83 g·cm^(-3)and bending strength of 155.44 MPa.After 30 thermal shocks(1000℃-room temperature,air cooling),the bending strength of sample A3 increases to 166.15 MPa with an enhancement rate of 6.89%,the corresponding thermal conductivity and specific heat capacity are 3.54 W·(m·K)^(-1)and 1.39 kJ·(kg·K)^(-1)at 800℃,and the thermal storage density is 1096 kJ·kg^(-1)(25-800 mullite ceramics;sintering properties;high-temperature thermal storage;thermal shock resistance).Mullite forms a dense and continuous interlaced network microstructure,which endows the samples high thermal storage density and high bending strength,but the decrease of bauxite/kaolin ratio leads to the decrease of mullite content,which reduces the properties of the samples. 展开更多
关键词 mullite ceramics sintering properties high-temperature thermal storage thermal shock resistance
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Minimizing Carbon Content with Three-in-One Functionalized Nano Conductive Ceramics:Toward More Practical and Safer S Cathodes of Li-S Cells 被引量:1
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作者 Ning Li Chang Sun +5 位作者 Jianhui Zhu Shun Li Yanlong Wang Maowen Xu Changming Li Jian Jiang 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2023年第3期31-39,共9页
Using porous carbon hosts in cathodes of Li-S cells can disperse S actives and offset their poor electrical conductivity.However,such reservoirs would in turn absorb excess electrolyte solvents to S-unfilled regions,c... Using porous carbon hosts in cathodes of Li-S cells can disperse S actives and offset their poor electrical conductivity.However,such reservoirs would in turn absorb excess electrolyte solvents to S-unfilled regions,causing the electrolyte overconsumption,specific energy decline,and even safety hazards for battery devices.To build better cathodes,we propose to substitute carbons by In-doped SnO_(2)(ITO)nano ceramics that own three-in-one functionalities:1)using conductive ITO enables minimizing the total carbon content to an extremely low mass ratio(~3%)in cathodes,elevating the electrode tap density and averting the electrolyte overuse;2)polar ITO nanoclusters can serve as robust anchors toward Li polysulfide(LiPS)by electrostatic adsorption or chemical bond interactions;3)they offer catalysis centers for liquid–solid phase conversions of S-based actives.Also,such ceramics are intrinsically nonflammable,preventing S cathodes away from thermal runaway or explosion.These merits entail our configured cathodes with high tap density(1.54 g cm^(−3)),less electrolyte usage,good security for flame retardance,and decent Li-storage behaviors.With lean and LiNO_(3)-free electrolyte,packed full cells exhibit excellent redox kinetics,suppressed LiPS shuttling,and excellent cyclability.This may trigger great research enthusiasm in rational design of low-carbon and safer S cathodes. 展开更多
关键词 flame retardance Li-S cells minimized carbon ratio nano conductive ceramics three-in-one functionality
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Physic, Chemical and Mineralogical Characterizations of Clays Used in the Making of Traditional Ceramics in the City of Katiola, C ôte d’Ivoire
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作者 Isabelle Linda He Grah Patrick Atheba +3 位作者 N’guadi Blaise Allou Patrick Drogui My Ali El Khakani Gildas Komenan Gbassi 《Journal of Minerals and Materials Characterization and Engineering》 2023年第4期81-91,共11页
In C ?te d’Ivoire, traditional ceramics are widely used in the form of pottery. The latter is used to store food, water and cereals. Analyzes (X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), ... In C ?te d’Ivoire, traditional ceramics are widely used in the form of pottery. The latter is used to store food, water and cereals. Analyzes (X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), inductive plasma optical emission spectrometry (ICP-OES), scanning electron microscopy (SEM) and analysis thermal gravimetric (ATG)) were carried out to determine the morphology, the chemical, physical and pedological constituents of these raw materials. It appears from this study that the clays used in the Mangoro pottery of Katiola contain silica SiO<sub>2</sub>, alumina Al<sub>2</sub>O<sub>3</sub> and iron oxide Fe<sub>2</sub>O<sub>3</sub> as well as kaolinite, muscovite, smectite and quartz. 展开更多
关键词 ceramics Characterization Clays KAOLINITE MUSCOVITE SMECTITE QUARTZ
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