Results in Physics
·
2017
·
IF 0.946
Haihua Chen,Hao Liang,Lingxiao Liu,Huishan Li,Kui Liu,Fang Peng
The Vickers hardness of the bulk TaB and nano-TaC ceramics sintered at high pressure and high temperature were measured by using a diamond indentation method. Our tests gave a maximum Vickers hardness of 13.9 GPa for TaB, and 19.2 GPa for nano-TaC ceramics under a load of 29.4 N. The hardness of nano-TaC-5 wt% Co composites was also measured under the same load for comparison, which was found to be much lower than that of TaB and nano-TaC. The relative densities calculated by the Archimedes method are 13.5 g/cm 3 for TaB and 13.6 g/cm 3 for nano-TaC. The averaged fracture toughness is 6.8 ± 0.3 MPa m 1/2 for TaB and 5.0 ± 0.2 MPa m 1/2 for nano-TaC. Our results show that the hardness of the TaB may not be as high as previous reports.
研究领域:
材料科学
·
陶瓷学
·
凝聚态物理
·
高温材料
·
超硬材料
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2018
·Vol. 44
·期 9
·10420-10425
·
IF 3.057
Yurun Feng,Xue Guo,Hongyu Gong,Yujun Zhang,Yu Liu,Xiao Lin,Junjie Mao
PDCs-SiCN(Fe) ceramics were successfully fabricated with different content of ferric acetylacetonate (FA) by polymer-derived method. The effects of FA on the phase composition, microstructure, resistivity, dielectric properties , magnetic properties and microwave absorption properties of PDCs-SiCN(Fe) ceramics in the range of 2–18 GHz were investigated. The samples presented amorphous structure with a few crystalline phases of α-Fe and free carbon in the gaps, which were expected to be good soft magnetic materials . The average real permittivity and imaginary permittivity of PDCs-SiCN(Fe) ceramics with 50 wt% FA was about 14.1 and 5.3 respectively. Furthermore, the PDCs-SiCN(Fe) ceramics with 50 wt% FA addition content showed the broad absorption bandwidth in the 5.1–8.4 GHz with RL ≤ −10 dB (> 90% absorption) at 4 mm.
研究领域:
材料科学
·
功能陶瓷
·
电磁特性
·
吸波材料
·
复合材料
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2017
·Vol. 43
·期 17
·15551-15555
·
IF 2.986
Youzhi Wang,Xue Guo,Yurun Feng,Xiao Lin,Hongyu Gong
Ferreous polymer-derived SiCN ceramics (PDCs-SiCN(Fe)) were successfully synthesized by precursor conversion method. The phase composition and microstructure of the obtained products were investigated by XRD , SEM and TEM . The result indicated a mainly amorphous structure with a few α-Fe,and graphite phases in the gaps. The conductivity, electromagnetic parameters and wave absorbing properties of the prepared ceramics were studied at the frequency band from 2 to 18 GHz. The reflectance of PDCs-SiCN(Fe) was about −10 dB (> 90% absorption) in the range of 4–16 GHz with 25 wt% nano-Fe 2 O 3 addition at the thickness 8 mm. The maximum value of dielectric and magnetic loss angle tangent was about 1.5, indicating PDCs-SiCN(Fe) ceramics possessed good absorption performance .
研究领域:
材料科学
·
陶瓷学
·
电磁学
·
功能材料
·
复合材料
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·Vol. 50
·期 4
·6598-6605
·
IF 5.2
Wei Peng,Jianglei Chang,Bin Wang,Zhen Liu,Genshui Wang,Shuxiang Dong
The ultrahigh piezoelectric coefficient (d 33 ≥ 1000 pC/N) exhibited by piezoelectric Pb(Zr,Ti)O 3 (PZT) ceramics not only captivates researchers but also holds considerable practical value across various applications. While significant progress has been made in enhancing piezoelectricity of PZT-based ceramics, novel mechanisms need to be proposed to explain the piezoelectric behavior of new systems with ultrahigh d 33 . In this study, we initially employ LiNbO 3 as an additive to enhance the piezoelectric properties of the Pb(Ni 1 / 3 Nb 2 / 3 )O 3 –PbZrO 3 –PbTiO 3 ceramics. and the optimal performance is achieved by incorporating 1.5 mol% of LiNbO 3 into the system, resulting in an ultrahigh d 33 ∼1178 pC/N ( d 33 * ∼1560 p.m./V (@ E = 5 kV/cm)). The corresponding mechanism for this superior piezoelectric response involves the AB-site co-doping effect, especially the ( Li Pb ′ − Nb Zr / Ti ∙ ) defect dipoles formed by the introduction of LiNbO 3 . In particular, the addition of LiNbO 3 leads to a more uniform distribution of domain sizes, thereby further enhancing the ultrahigh piezoelectricity. These findings pave the way for a deeper under-standing of the origin of ultrahigh piezoelectric properties and make substantial contributions to the advancement of piezoelectric materials for practical applications in electromechanical devices.
研究领域:
材料科学
·
功能陶瓷
·
压电材料
·
固态物理
·
电子显微学
·
介电材料
·
无机非金属材料
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·Vol. 50
·期 9
·15202-15208
·
IF 5.1
Xiong Huang,Pengfei Wang,Jianwei Zhao,Jun Yang,Zhenxiao Fu,Xiuhua Cao,Lei Zhang,Shuhui Yu,Rong Sun
As a dielectric material , BaTiO 3 -based ceramics are desirable for high performance ultra-thin multilayer ceramic capacitors (MLCCs) application. In this work, BaTiO 3 -based dielectric ceramics with superior dielectric properties were synthesized using a reducing atmosphere sintering process . It is found that the contribution of “wet" grain-boundary diffusion become significant as the oxygen partial pressure increases, resulting to a larger grain size and higher permittivity. Especially, for the specimen sintered in higher oxygen partial pressure , the stable temperature coefficient of capacitance (TCC) is dominated by irreversal domain due to the increase of super-lattice phase. Samples with higher oxygen partial pressure exhibit a higher permittivity of 2700 and better permittivity-temperature stability. Furthermore, ultra-thin MLCCs with thickness of 1 μm and capacitance of 10 μF and the TCC of X7R were successfully fabricated. This work provides a comprehensive explanation demonstrating upon the significant roles of grain size and defect engineering in the dielectric performance in BaTiO 3 -based ceramics, and points out an avenue to obtain excellent permittivity-temperature stability in ultra-thin MLCCs.
研究领域:
材料科学
·
电子陶瓷
·
介电材料
·
固态物理
·
功能陶瓷
·
电容器技术
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2024
·Vol. 59
·期 36
·16909-16917
·
IF 3.5
Xie Jingru,Fu Zhifen,Cheng Qing,Chen Chen,She Yubin,Li Xiangyi
Low temperature co-fired ceramics (LTCC) technology is extensively utilized to meet the requirements of device integration and miniaturization. Low-fired Li 3 Mg 2 NbO 6 ceramics doped with x wt% Li 2 O–MgO–B 2 O 3 –CaF 2 –SiO 2 glass (LMBCS, x = 0.5, 1.0, 1.5, 2.0) were prepared by the solid-state reaction method for applications in microwave communication materials. All samples exhibited a single-phase Li 3 Mg 2 NbO 6 structure. The addition of LMBCS glass effectively reduced the sintering temperature of Li 3 Mg 2 NbO 6 ceramics from 1250 °C to 875 °C. And adding LMBCS glass improved the Q × f value of Li 3 Mg 2 NbO 6 ceramics. The Li 3 Mg 2 NbO 6 -1.0wt% LMBCS ceramics exhibited outstanding microwave dielectric properties: ε r = 16.8, Q × f = 89,495 GHz, τ f = − 27.4 ppm/°C at 875 °C, which indicates that this ceramic is potential candidate materials for LTCC.
研究领域:
材料科学
·
电子陶瓷
·
功能材料
·
无机非金属材料
·
微波通信材料
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·Vol. 51
·期 6
·6968-6975
·
IF 5.1
Xinrong Yang,Deqin Chen,Guobin Zhu,Siyu Xiong,Xiaowei Zhu,Laijun Liu,Chunchun Li
The impact of configurational entropy on the microwave dielectric properties of LnNbO 4 fergusonite was investigated by designing a series of high-entropy counterparts, including (La, Nd, Sm, Ho, Yb, Y)NbO 4 (6RNO), (La, Nd, Sm, Eu, Ho, Yb, Y)NbO 4 (7RNO), (La, Nd, Sm, Eu, Gd, Ho, Yb, Y)NbO 4 (8RNO), and (La, Nd, Sm, Eu, Gd, Ho, Tm, Yb, Lu, Y)NbO 4 (10RNO). Simply prepared by the solid-state route, a pure phase with a monoclinic fergusonite structure of space group C /2 c was obtained. By comparing the microstructural evolution and lattice vibration modes, an analysis was conducted on the variations in microwave dielectric performances. It was confirmed that the permittivity ( ε r ) is primarily influenced by relative density, while the quality factor ( Q × f ) exhibits a strong correlation with packing fraction and lattice vibrations. The resonant frequency temperature coefficient (τ f ) is significantly associated with bond valence. The optimal microwave dielectric properties were achieved in 7RNO ceramics at a temperature of 1270 °C, resulting in a relative density of 95.43 %. The microwave dielectric properties were measured as ε r = 18.62, Q × f = 35200 GHz, τ f = −23.28 ppm/°C. The present study expands the application of entropy engineering to achieve ultrahigh configurational entropy in microwave dielectric ceramics . These findings demonstrate that optimizing the configuration entropy is an effective approach for manipulating the dielectric properties, thereby providing valuable insights for material component design.
研究领域:
材料科学
·
无机非金属材料
·
功能陶瓷
·
介电材料
·
固态化学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2019
·Vol. 30
·期 10
·9983-9988
·
IF 2.195
Ma Panfei,Zhang Huimin,Chen Mingxing,Liu Ting,Chang Aimin,Su Zhi
Highly dense LaCrO 3 negative temperature coefficient (NTC) thermistor ceramics by low-heating solid-state method have been successfully synthesized in air ambient. The X-ray diffraction analysis has shown that both of the calcined powders and as-sintered ceramics crystallize in a perovskite structure. The relative densities of the ceramics synthesized by Cr(NO 3 ) 3 ·9H 2 O and the ceramics synthesized by CrCl 3 ·6H 2 O are 91% and 65%, respectively. The relationship between lnρ and 1000/T shows an approximate line in the measured temperature range. The values of ρ 25 and B 0/25 of the ceramics synthesized by Cr(NO 3 ) 3 ·9H 2 O and the ceramics synthesized by CrCl 3 ·6H 2 O are 424.8 Ω cm, 3252 K and 1835.9 Ω cm, 3636 K, respectively.
研究领域:
材料科学
·
无机非金属材料
·
电子陶瓷
·
热敏材料
✓ 已验证
DOI
高影响因子
IONICS
·
2019
·Vol. 26
·期 1
·263-272
·
IF 2.289
Luo X. Y.,Meng B.,Xia Z. D.,Chen Q. B.,Dong D. Z.,Zhao M. Y.
In order to investigate the effects of Na 2 CO 3 /ZnO co-addition on the sinterability and electrical conductivity of BaZr 0.1 Ce 0.7 Y 0.1 Sc 0.1 O 3-δ (BZCYSc) ceramic, Na 2 CO 3 and ZnO were added and BZCYSc/ZnO/Na 2 CO 3 ceramic was prepared by mechanical ball milling and high-temperature sintering in air. The crystalline structure, micro-morphology, chemical composition, density, and electrical conductivity of the sintered ceramics were characterized by XRD, SEM, EDS, Archimedes method, and electrochemical impedance spectrum, respectively. The grains size of BZCYSc-2%ZnO-5%Na 2 CO 3 is about 2.5~5 μm. Na 2 CO 3 /ZnO co-addition is beneficial to improve the sinterability and electrical conductivity of BZCYSc. The sintering temperature of BZCYSc can be lowered from 1550 to 1350 °C when 2 mol%ZnO is added. At 550 °C, the electrical conductivities of BZCYSc-2%ZnO-10%Na 2 CO 3 and BZCYSc are 1.90 × 10 −3 S/cm and 1.81 × 10 −3 S/cm. The activation energies of BZCYSc and BZCYSc-2%ZnO-10%Na 2 CO 3 are 0.7529 eV and 0.5641 eV, respectively.
研究领域:
材料科学
·
无机非金属材料
·
固态离子学
·
能源材料
·
陶瓷工程
✓ 已验证
DOI
高影响因子
Journal of Energy Storage
·
2024
·
IF 8.9
Ying Lu,Xiaochun Wang,Peng Li,Juan Du,Peng Fu,Jigong Hao,Wei Li
Ceramic capacitors having great energy-storage performance (ESP) are receiving more and more concern in the electronics industry. In this paper, high ESP is obtained in 0.6Bi 0.5 Na 0.5 TiO 3 –0.4Bi 0.2 Sr 0.7 TiO 3 (BNT-BST)-based samples through doping the Sr(Sc 0.5 Nb 0.5 )O 3 (SSN) component. The results show that the recoverable energy density ( W rec ) and efficiency ( η ) of the materials will be significantly improved by adjusting the relaxation characteristics and domain structure engineering. In addition, the breakdown filed of ceramics is also improved by inhibition grain growth. The BNT-BST-0.15SSN ceramic has achieved high comprehensive ESP ( W rec = 5.49 J/cm 3 , η = 93.6 %) at an electric field of 455 kV/cm. Meanwhile, the ceramic shows outstanding temperature (25–160 °C), frequency (1–500 Hz) and cycle (1–10 4 ) stability (the variation of W rec / η < 5 %). Therefore, the BNT-BST-0.15SSN ceramic is expected to be a suitable candidate of environmentally friendly materials as advanced pulsed capacitor application.
研究领域:
材料科学
·
功能陶瓷
·
电介质物理
·
能源存储
·
电子材料
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·Vol. 47
·期 5
·6842-6847
·
IF 3.83
Shunjin Xiong,Rongxia Huang,Congfei Peng,Yejing Dai,Jiajiu Li,Wen Bai,Hua-Tay Lin
A series of HfO 2 -modified (Bi 0 .475 Na 0 . 405 K 0 . 055 Li 0.015 ) 0.95 Ba 0 . 05 Ti (1- x ) Hf x O 3 ( x = 0–0.015) lead-free ceramics were prepared. Results of detailed characterizations showed that the addition of HfO 2 had little influence on the grain size, and all of the samples showed the pure perovskite structure. As the Hf 4+ content increases, the samples changed from the normal ferroelectric phase to the ergodic relaxor state at room temperature, and the ceramics with x = 0.01 showed a high electro-strain of 0.295% at 6 kV/mm. Therefore, this study provides a new insight into of how the HfO 2 addition influences the ferroelectric property of the BNT-based ceramics by B-site substitution.
研究领域:
材料科学
·
无机非金属材料
·
功能陶瓷
·
铁电材料
·
压电材料
✓ 已验证
DOI
高影响因子
OPTICAL MATERIALS
·
2017
·
IF 2.238
Jianjian Sun,Bijun Fang,Shuai Zhang,Zhihui Chen,Jianning Ding,Xiangyong Zhao,Haosu Luo
Er 3+ -doped Na 0.5 Bi 0.5 TiO 3 (Er-doped NBT) ceramics were prepared via a hydrothermal method . High sintering active Er-doped NBT nano cubic particles with perovskite structure were synthesized at hydrothermal condition of 200 °C for 24 h in 12 M NaOH solution, which were self-assembled via in situ crystallization mechanism by the initially as-grown nanowires. The Er-doped NBT ceramics sintered at 1100 °C for 2 h exhibit pure rhombohedral perovskite structure, high densification and rather homogenous microstructure morphology. Under 488 nm light excitation , the strong green emission peaks centering at 530 nm and 550 nm and the weak red emission peaks locating at 665 nm and 735 nm are excited, which can be attributed to the 2 H 11/2 , 4 S 3/2 , 4 F 9/2 and 4 I 9/2 → 4 I 15/2 transitions, respectively. The maximum emission intensity is obtained when the Er doping content reaches 1.0 mol%. A strong upconversion emission peak centering around 550 nm in green light range is excited under 800 nm light excitation, which is correlated with the 4 S 3/2 → 4 I 15/2 transition.
研究领域:
材料科学
·
无机非金属材料
·
功能陶瓷
·
光电子学
·
固体化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）