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Enhancement of Piezoelectric Properties in CaBi_(4)Ti_(4)O_(15)-based Ceramics through Bi^(3+) Self-doping Strategy
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作者 ZHOU Yangyang ZHANG Yanyan +4 位作者 YU Ziyi FU Zhengqian XU Fangfang LIANG Ruihong ZHOU Zhiyong 《无机材料学报》 北大核心 2025年第6期719-728,共10页
High-temperature piezoelectric vibration sensors are the preferred choice for structural health monitoring in harsh environments such as high temperatures and complex vibrations.Bismuth layer-structured CaBi_(4)Ti_(4)... High-temperature piezoelectric vibration sensors are the preferred choice for structural health monitoring in harsh environments such as high temperatures and complex vibrations.Bismuth layer-structured CaBi_(4)Ti_(4)O_(15)(CBT)high-temperature piezoelectric ceramics,with high Curie temperature(TC),are the key components for piezoelectric vibration sensors operating at temperatures exceeding 500℃.However,their low piezoelectric coefficient(d_(33))greatly limits their high-temperature applications.In this work,a novel Bi^(3+)self-doping strategy was employed to enhance the piezoelectric performance of CBT ceramics.The enhancement is attributed to an increase in the number of grain boundaries,providing more sites for space charge accumulation and promoting formation of space charge polarization.Furthermore,given that space charge polarization predominantly occurs at low frequencies,dielectric temperature spectra at different frequencies were used to elucidate the mechanism by which space charge polarization enhances piezoelectric properties of CBT ceramics.Excellent overall performance was achieved for the CBT-based high-temperature piezoelectric ceramics.Among them,TC reached 778℃,d_(33) increased by more than 30%,reaching 20.1 pC/N,and the electrical resistivity improved by one order of magnitude(reaching 6.33×10^(6)Ω·cm at 500℃).These advancements provide a key functional material with excellent performance for practical applications of piezoelectric vibration sensors at 500℃and above. 展开更多
关键词 high-temperature piezoelectric ceramic bismuth layer structure SELF-DOPING space charge polarization oxygen vacancy
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Sintering Behaviour and Dielectric Properties of MnCO_(3)-doped MgO-based Ceramics
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作者 WANG Zhixiang CHEN Ying +2 位作者 PANG Qingyang LI Xin WANG Genshui 《无机材料学报》 北大核心 2025年第1期97-103,共7页
Ceramic dielectric materials with high dielectric strength and mechanisms of their internal factors affecting dielectric strength are significantly valuable for industrial application,especially for selection of suita... Ceramic dielectric materials with high dielectric strength and mechanisms of their internal factors affecting dielectric strength are significantly valuable for industrial application,especially for selection of suitable dielectric materials for high-power microwave transmission devices and reliable power transmission.Pure magnesium oxide(MgO),a kind of ceramic dielectric material,possesses great application potential in high-power microwave transmission devices due to its high theoretical dielectric strength,low dielectric constant,and low dielectric loss properties,but its application is limited by high sintering temperature during preparation.This work presented the preparation of a new type of multiphase ceramics based on MgO,which was MgO-1%ZrO_(2)-1%CaCO_(3-x)%MnCO_(3)(MZCM_(x),x=0,0.25,0.50,1.00,1.50,in molar),and their phase structures,morphological features,and dielectric properties were investigated.It was found that inclusion of ZrO_(2) and CaCO_(3) effectively inhibited excessive growth of MgO grains by formation of second phase,while addition of MnCO_(3) promoted the grain boundary diffusion process during the sintering process and reduced activation energy for the grain growth,resulting in a lower ceramic sintering temperature.Excellent performance,including high dielectric strength(Eb=92.3 kV/mm)and quality factor(Q×f=216642 GHz),simultaneously accompanying low dielectric loss(<0.03%),low temperature coefficient of dielectric constant(20.3×10^(–6)℃^(–1),85℃)and resonance frequency(–12.54×10^(–6)℃^(–1)),was achieved in MZCM1.00 ceramics under a relatively low sintering temperature of 1350℃.This work offers an effective solution for selecting dielectric materials for high-power microwave transmission devices. 展开更多
关键词 MgO ceramic dielectric strength sintering temperature growth activation energy
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Microstructure and Oxidation Behavior of ZrB_(2)-SiC Ceramics Fabricated by Tape Casting and Reactive Melt Infiltration 被引量:1
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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 ZrB_(2)-SiC oxidation behavior reactive melt infiltration
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Predicting the Degradability of Bioceramics through a DFT-based Descriptor
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作者 CHEN Mengjie WANG Qianqian +1 位作者 WU Chengtie HUANG Jian 《无机材料学报》 SCIE EI CAS CSCD 北大核心 2024年第10期1175-1181,I0007-I0009,共10页
Bioceramics have attracted extensive attention for bone defect repair due to their excellent bioactivity and degradability.However,challenges remain in matching the rate between bioceramic degradation and new bone for... Bioceramics have attracted extensive attention for bone defect repair due to their excellent bioactivity and degradability.However,challenges remain in matching the rate between bioceramic degradation and new bone formation,necessitating a deeper understanding of their degradation properties.In this study,density functional theory(DFT)calculations was employed to explore the structural and electronic characteristics of silicate bioceramics.These findings reveal a linear correlation between the maximum isosurface value of the valence band maximum(VBM_(Fmax))and the degradability of silicate bioceramics.This correlation was subsequently validated through degradation experiments.Furthermore,the investigation on phosphate bioceramics demonstrates the potential of this descriptor in predicting the degradability of a broader range of bioceramics.This discovery offers valuable insights into the degradation mechanism of bioceramics and holds promise for accelerating the design and development of bioceramics with controllable degradation. 展开更多
关键词 BIOCERAMICS SILICATE PHOSPHATE first PRINCIPLES degradation
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Rate and Cycling Performance of Ti and Cu Dopedβ-NaMnO_(2) as Cathode of Sodium-ion Battery
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作者 ZHOU Jingyu LI Xingyu +3 位作者 ZHAO Xiaolin WANG Youwei SONG Erhong LIU Jianjun 《无机材料学报》 SCIE EI CAS CSCD 北大核心 2024年第12期1404-1412,I0010,I0011,I0012,共12页
Sodium-ion batteries are economical and environmentally sustainable energy storage batteries.Among them,β-NaMnO_(2),a promising sodium-ion cathode material,is a manganese-based oxide with a corrugated laminar structu... Sodium-ion batteries are economical and environmentally sustainable energy storage batteries.Among them,β-NaMnO_(2),a promising sodium-ion cathode material,is a manganese-based oxide with a corrugated laminar structure,which has attracted significant attention due to its structural robustness and relatively high specific capacity.However,it has short cycle life and poor rate capability.To address these issues,Ti atoms,known for enhancing structural stability,and Cu atoms,which facilitate desodiation,were doped intoβ-NaMnO_(2) by first-principles calculation and crystal orbital Hamilton population(COHP)analysis.β-NaMn_(0.8)Ti_(0.1)Cu_(0.1)O_(2) exhibits a notable increase in reversible specific capacity and remarkable rate properties.Operating at a current density of 0.2C(1C=219 mA·g^(–1))and within a voltage range of 1.8–4.0 V,the modified material delivers an initial discharge capacity of 132 mAh·g^(–1).After charge/discharge testing at current densities of 0.2C,0.5C,1C,3C,and 0.2C,the material still maintains a capacity of 110 mA h·g^(–1).The doping of Ti atoms slows down the changes in the crystal structure,resulting in only minimal variation in the lattice constant c/a during the desodiation process.Mn and Cu engage in reversible redox reactions at voltages below 3.0 V and around 3.5 V,respectively.The extended plateau observed in the discharge curve below 3.0 V signifies that Mn significantly contributes to the overall battery capacity.This study provides insights into modifyingβ-NaMnO_(2) as a cathode material,offering experimental evidence and theoretical guidance for enhancing battery performance in Na-ion batteries. 展开更多
关键词 FIRST-PRINCIPLES sodium-ion battery layered cathode material
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Ablative Properties of SiC_(p)Doped C_(f)/Li_(2)O-Al_(2)O_(3)-SiO_(2)Composites
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作者 LIN Yuanwei JING Zhao +4 位作者 CHEN Hetuo LI Jiaheng QIN Xianpeng ZHOU Guohong WANG Shiwei 《无机材料学报》 北大核心 2025年第10期1153-1162,共10页
In a high heat flux ablative environment,the surface temperature of aircraft rises rapidly,leading to traditional high thermal conductivity materials being ineffective at protecting internal metal components.In this s... In a high heat flux ablative environment,the surface temperature of aircraft rises rapidly,leading to traditional high thermal conductivity materials being ineffective at protecting internal metal components.In this study,continuous carbon fiber reinforced Li_(2)O-Al_(2)O_(3)-SiO_(2)(C_(f)/LAS)glass ceramic composites doped with SiC particles(SiC_(p))were prepared by slurry immersion winding and hot pressing sintering.Effect of matrix crystallinity on ablative properties of the composites under ultra-high heat flux was investigated.By utilizing heat absorption and low thermal conductivity characteristics associated with SiO_(2)gasification within composite materials,both surface and internal temperatures of these materials are effectively reduced,thereby ensuring the safe operation of aircraft and electronic devices.Results indicate that the average linear ablation rate of composites doped with 10%(in mass)of SiC_(p)significantly decreases at a heat flux of 20 MW/m^(2).Transmission electron microscope observation reveals that the doped glass matrix exhibits increased crystallinity,reduced internal stress,and minimized lattice distortion,thereby enhancing the composites’high-temperature performance.However,excessive SiC_(p)doping leads to reduced crystallinity and deteriorated ablation performance.Ultimately,the average linear ablation rate of C_(f)/LAS composites with 10%(in mass)SiC_(p)at 20 MW/m^(2)heat flux is comparable to that of commercial carbon/carbon composites,accompanied by providing lower thermal conductivity and higher bending strength.This novel high-performance C_(f)/LAS composite is cost-effective,short-cycled,and suitable for mass production,offering promising potential for widespread application in ablation-resistant components of hypersonic vehicles. 展开更多
关键词 ablation-resistant C_(f)/LAS composite SiC doping crystallinity of glass matrix long-range ordered
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Powder Characteristics on the Rheological Performance of Resin-based Zirconia Suspension for Stereolithography 被引量:7
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作者 LI Xing-Bang ZHONG He +2 位作者 ZHANG Jing-Xian DUAN Yu-Sen JIANG Dong-Liang 《无机材料学报》 SCIE EI CAS CSCD 北大核心 2020年第2期231-235,共5页
As for ceramic stereolithography technique,the preparation of suitable resin-based ceramic slurry is of primary importance.In this study,the effects of powder characteristics such as specific surface area,particle siz... As for ceramic stereolithography technique,the preparation of suitable resin-based ceramic slurry is of primary importance.In this study,the effects of powder characteristics such as specific surface area,particle size and distribution,particle morphology on the rheological behavior of zirconia resin-based suspensions were investigated intensively.Results show that the specific surface area of the powder is the most important factor affecting slurry viscosity.Choosing low specific surface area and quasi-spherical shaped powder is more likely to obtain low viscosity slurries.In addition,the influence of solid loading on the flow behavior were also studied using Krieger-Dougherty model.Zirconia samples with the relative density of(97.83±0.33)%were obtained after sintering at 1550℃.No obvious abnormal grain growth in the microstructure of the sintered body is observed.Results indicate that after the optimization of the processing parameters with the help of rheology characterization,complex-shaped high-quality zirconia parts can be obtained using the stereolithography technique. 展开更多
关键词 ZIRCONIA ceramic stereolithography SLURRY rheological properties
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Microwave Assisted Sintering and Photoluminescence Properties of BaaSi6OleNe:Eu^2+ Green Phosphors 被引量:3
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作者 HAN Bin WANG Yi-Fei +1 位作者 LIU Qian HUANG Qing 《无机材料学报》 SCIE EI CAS CSCD 北大核心 2015年第3期330-336,共7页
Eu^2+-doped Ba3Si6012N2 green phosphors were prepared by microwave assisted sintering method at 1275℃ for 4 h, while the counterparts using conventional solid-state reaction method were synthesized at temperature hi... Eu^2+-doped Ba3Si6012N2 green phosphors were prepared by microwave assisted sintering method at 1275℃ for 4 h, while the counterparts using conventional solid-state reaction method were synthesized at temperature higher than 1300℃ and for to 10 h. Microwave assisted sintering could reduce the activation energy and enhance the diffu- sion rate, thus greatly improved the sintering. Moreover, the influence of Si3N4 content on phase formation, morphol- ogy, absorption, and quantum efficiency, and photoluminescence properties of phosphors were studied. As a result, the Ba3Si6OI2N2:Eu^2+ samples sintered by microwave assisted sintering method have a higher phase purity and photo- luminescence intensity under ultraviolet excitation as compared with samples sintered in the conventional tube furnace The proposed method is a potential preparation method for the oxynitride phosphors with strong photoluminescence and high phase purity. 展开更多
关键词 Ba3S16012N2:Eu^2+ PHOSPHORS OXYNITRIDE MICROWAVE assisted SINTERING PHOTOLUMINESCENCE
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Solidification and Crystal Growth on the SJ-10 Recoverable Scientific Experiment Satellite
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作者 YIN Zhigang ZHANG Xingwang +3 位作者 WU Jinling LI Xiaoya YU Jianding YUAN Zhangfu 《空间科学学报》 CAS CSCD 北大核心 2018年第5期836-838,共3页
The low-gravity environment aboard the space provides a unique platform for understanding crystal-growth-related phenomena that are masked by gravity on the Earth and for exploring new crystal growth techniques. We ha... The low-gravity environment aboard the space provides a unique platform for understanding crystal-growth-related phenomena that are masked by gravity on the Earth and for exploring new crystal growth techniques. We have characterized the wetting behavior of metal alloys and carried out melt growth of compound semiconductors under the support of materials science program in the SJ-10 recoverable satellite. We found that interfacial reaction plays a significant role in the interfacial evolution of Sn-based alloys. Detached growth of InAsSb was realized under microgravity, whereas during the terrestrial experiment the crystal and the crucible wall contact with each other. Moreover, the suppression of buoyancy-driven convection results in a more uniform composition distribution in the InGaSb and Bi_2Te_3-based semiconductor alloys. 展开更多
关键词 科学实验卫星 水晶生长 INASSB 金属合金 复合半导体 半导体合金 生长技术 材料科学
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