JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2024
·Vol. 35
·期 34
·1-9
·
IF 2.8
Gao Dawei,Ma Juncheng,Zhang Jiafen,Shi Qingang,Xiong Zhe,Zhang Xing,Tang Bin
The occurrence of "dark holes" is a common phenomenon in TiO 2 -based ceramics, resulting from the reduction of Ti 4+ under high-temperature and low-oxygen partial pressure sintering conditions. To achieve low dielectric loss, Ca 0.61 Nd 0.26 Ti 1- x Cu x O 3 ceramics were designed and prepared in this work. The results indicate that moderate doping of CuO not only enhances insulation resistivity and Q × f value but also reduces the positive τ f value. The Ca 0.61 Nd 0.26 Ti 0.98 Cu 0.02 O 3 sample exhibited the highest Q × f value of 16,895 GHz, contributing to the miniaturization and insertion loss of microwave devices.
研究领域:
材料科学
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电子工程
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Ying Xue,Zhuo Wang,Jinteng Kang,Caidan Hou,Ronghui Ye,Ting Zhao,Xin Li
TiO 2 -based colossal dielectric ceramics have emerged as a prominent research focus in recent years. However, their further applications have been constrained by several key limitations, including the requirement of high sintering temperature (>1400 °C), relatively high dielectric loss (>0.05, 1 kHz), and temperature stability (<200 °C). This study reports rutile (In 0.5 Ta 0.5 ) 0.1 Ti 0.87 O 1.88 F 0.12 ceramics at 1220 °C sintering using 12 % InF 3 as the acceptor In 3+ source, which exhibits a colossal dielectric constant (1.1 × 10 5 ) and an ultra-low dielectric loss (0.0071) at 1 kHz and room temperature, even loss values below 0.04 (20 Hz - 100 kHz). Notably, the thermal stabilities (10 kHz, 100 kHz) simultaneously satisfy X9E (Δε r /ε 25 °C ≤ ±4.7 %) above 300 °C. F − not only supplies electrons to enhance the semiconductivity of grains, but also decreases the oxygen vacancy and average grain size (270 ± 12.53 nm) to improve grain boundaries resistances, which reduces dielectric loss and enhances frequency and temperature stabilities. As a result, the dielectric mechanism is mainly related to internal barrier layer capacitor (IBLC) and high grain boundary resistance. Therefore, this strategy provides a creative design for developing TiO 2 -based ceramics.
研究领域:
材料科学
·
电子工程
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Xingyu Chen,Yeqing Guan,Zhaolin Zhong,Fenglin Wang,Wei Li,Haijun Mao,Zhuofeng Liu,Weijun Zhang
The effect of Zr 4+ substitution for Ti 4+ on the phase evolution and microwave dielectric properties of (Cu 1/3 Nb 2/3 ) 0.25 Ti 0.75- x Zr x O 2 (0 = x ≤ 0.35) ceramics prepared via conventional solid-state method has been investigated. With the increase of Zr substitution, the ceramics exhibit a gradual phase transition from a tetragonal rutile phase to an orthorhombic srilankite phase, where the synthesis of the srilankite phase at atmospheric pressure and temperature below 1200 °C in this study is reported for the first time. The crystal structure is tetragonal rutile type for the unsubstituted composition, orthorhombic srilankite type for the compositions with x > 0.30, and the compositions in between is a two-phase region with a mixture of rutile and srilankite. The Zr substitution has a great influence on the microstructure of the ceramics. In particular, for compositions where x > 0.1, the grain boundaries are surrounded by elongated powdery particles. The microwave dielectric properties of the ceramics are closely related to the phase transition process, in which Q × f is significantly improved and τ f decreases almost linearly with the increase of the content of srilankite phase. Optimum microwave dielectric properties with a permittivity of 35.1, a Q × f value of 7270 GHz, and a near-zero τ f of 9.0 ppm/°C are obtained in the ceramics with x = 0.3 sintered at 1150 °C for 4 h, which provides a new option for microwave devices requiring medium-permittivity dielectric ceramics .
研究领域:
材料科学
·
电子材料
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DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Ying Xue,Zhuo Wang,JinTeng Kang,Ting Zhao,Ronghui Ye,Xin Li
With the rapid development of integrated circuits and microelectronic devices, the research of colossal dielectric constant ceramics has been greatly promoted. In this study, (In 0.5 Ta 0.5 ) 0.1 Ti 0.9 O 2- x F x ( x = 0, 0.03, 0.06, and 0.09) ceramics were synthesized using a conventional solid-phase sintering method in an Air atmosphere. When the concentration is 0.06, the colossal dielectric constant (ε = 10 5 ) and dielectric loss (tan δ = 0.068) were obtained at 1 kHz. The impedance spectra confirm that the materials have semiconductor grains and insulating grain boundaries, which originates from polaron polarization and electron hopping polarization. Meanwhile, the generation of oxygen vacancies ( V O · · ) is restricted because of the F − substitutional O 2 − sites, increasing the grain boundaries resistance and leading to low dielectric loss. Therefore, this anion doping method can be used as a simple and scalable way to provide new ideas to further progress the requirements of dielectric materials for integrated electronics.
研究领域:
材料科学
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电子工程
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2024
·Vol. 35
·期 11
·1-12
·
IF 2.8
Yang Zaizhi,Wang Xi,Zhang Liang,Li Hailing,Zhang Hui,Xu Dong
Flash sintering is considered a promising energy-saving and efficient technology for preparing high-temperature ceramics. The effects of limited current on flash sintering parameters, microstructure, and electrical properties of (La 1/2 , Ta 1/2 ) 0.02 Ti 0.98 O 2 ceramic were investigated by the XRD, SEM, XPS, and precision impedance analyzer. With limiting current increase, the grain size of flash sintering sample increases gradually, and the relative density increases first and then decreases. The average grain size is about 1 μm, and the highest relative density is 96.9%. Joule heating runaway and oxygen vacancy defect lead to rapid densification of flash sintering La and Ta co-doped TiO 2 ceramics. According to the EPDD model, doped La 3+ and Ta 5+ ions increase the concentration of oxygen vacancies and free electrons, lead to local polarization of carriers, and obtain a giant dielectric constant of ε ’ = 7.6 × 10 4 and low dielectric loss of tanδ = 0.11. At high temperature, electrons break free from the constraints of defect clusters and accumulate at the interface, leading to interface polarization due to the IBLC model. The giant dielectric properties originate from the combined effect of EPDD and IBLC model.
研究领域:
材料科学
·
陶瓷工程
·
电气工程
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DOI
高影响因子
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
·
2024
·
IF 4.3
Panpan Xu,Congli Guo,Wentao Hao,Li Sun,Ensi Cao
The internal barrier layer capacitance effect substantially contributes to the colossal permittivity in In and Nb co-doped TiO 2 (INTO) ceramics. Therefore, enhancing grain boundary density and ceramic compactness can efficaciously reduce their low-frequency dielectric loss . In this investigation, Bi 2 O 3 addition was utilized to aid sintering and refine grains for INTO ceramics. The results reveal that Bi-doped INTO ceramics, in contrast to their undoped counterparts, exhibit a more refined and compact grain structure with a significant increase in the quantity of grain boundaries. Moreover, a noticeable reduction in low-frequency dielectric loss from above 0.1 to below 0.05 and enhanced frequency stability of permittivity from below 10 Hz to approximately 10 kHz were observed, along with a decrease in the sintering temperature to 1300 °C. In comparison to undoped INTO ceramics, Bi doping also enhances the withstand voltage capability by a factor of 1.5–4 for Bi-doped INTO ceramics. However, as the sintering temperature of Bi-doped INTO ceramics increases and the grain size enlarges, their breakdown voltage gradually decreases, but the non-linear coefficient of current-voltage characteristics progressively increases. Analysis of complex impedance spectra confirms that the increased grain boundary density and resistance in Bi-doped INTO ceramics is the primary factor for the enhanced dielectric properties and withstand voltage capability.
研究领域:
材料科学
·
电子工程
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Lingfang Zou,Zhuan Li,Zonglong Gao,Fu Chen,Wenjie Li,Yong Yu,Yimin Li,Peng Xiao
Improving the piezoelectric activity of lead zirconate titanate (PZT) ceramics is of great importance for practical applications. In this study, the influence of Pr 3+ doping on the ferroelectric phase composition, microstructure, and electric properties on the A-site of (Pb 1-1.5x Pr x )(Zr 0.52 Ti 0.48 )O 3 is extensively investigated. A dense and fine microstructural sample is obtained with the introduction of Pr 3+ . The results show that the morphotropic phase boundary (MPB) moves to the rhombohedral phase region. The rhombohedral and tetragonal phases exhibit an ideal coexistence in the 4 mol.% Pr 3+ doped (PPZT4) samples. Lead vacancy and the reduction of the potential energy barrier are considered to be the key mechanisms for donor doping, which is upheld by the Pr 3+ doping. Combining the I-E hysteresis loops with the P-E hysteresis loops, it becomes apparent that both contribution maximums of the domain switching and residual polarisation are in PPZT4. Moreover, the thermal aging resistance of PZT is improved by doping, and the temperature stability is optimised from 83% in PZT to 96% in PPZT4. Hence, an appropriate amount of Pr 3+ doping can effectively improve the piezoelectric activity of PZT ceramics in the MPB area and optimise the performance stability of the material under application temperatures.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Mengting Jiang,Chenying Shi,Yuling Liu,Xiaopeng Li,Tengfei Deng
The mechanism of Mg 2+ introduction on the thermal expansion properties of Al 2 TiO 5 ceramics was elucidated through experimental characterization and theoretical calculation for Mg x Al 2(1-x) Ti 1+x O 5 (x = 0, 0.25, 0.50, 0.75). Results showed that as x increased from 0 to 0.75, the calculated thermal expansion coefficient (single-crystal) exhibited minimal variation, while the apparent thermal expansion coefficient (polycrystalline) increased from 0.09 × 10 -6 K -1 to 3.85 × 10 -6 K -1 (1000 °C). The low apparent thermal expansion of Al 2 TiO 5 (x = 0) was attributed to microcrack healing and pore compensation effects. For x = 0.75, the enhanced apparent thermal expansion was correlated with reduced microcrack formation and improved densification. The incorporation of Mg 2+ reduced octahedral distortion and lattice stiffness, thereby suppressing transverse vibrations of bridging oxygen atoms and contraction along the c-axis. This reduced thermal expansion anisotropy and minimized microcrack formation. Additionally, as Mg 2+ content increased from x = 0 to x = 0.75, the porosity reduced from (11.23 ± 0.13) % to (3.96 ± 0.24) %, thereby weakening the pore compensation effect. These findings provide valuable insights for designing Al 2 TiO 5 -based ceramics with low thermal expansion.
研究领域:
材料科学
·
无机非金属材料
·
热物理性能
✓ 已验证
产品关联
DOI
高影响因子
Journal of Advanced Dielectrics
·
2014
·
IF 0
Juan Li,Renli Fu,Yue Xu,Zhenxiao Fu,Hongjuan Su
The TiO 2 ceramics doped with nano CuO were fabricated by the conventional solid-state reaction method. The crystal structure, microstructure, microwave dielectric properties and lattice vibrations of TiO 2 ceramics doped with nano CuO have been investigated. Nano CuO with higher sintering capability worked as flux former and effectively improved the sintering process of TiO 2 ceramics. The microwave dielectric properties of TiO 2 doped with nano CuO were much better than that doped with micron CuO at the same doping content. Raman spectra showed that the full width at half maximum of E g mode of TiO 2 doped with micron CuO was larger than nano CuO doped ones, which indicated a poor crystalline and a short phonon lifetime. TiO 2 doped with 1 wt.% nano CuO , sintered at 950°C for 2 h had compact and homogeneous microstructure and possessed the following dielectric properties: ε r = 106, Q × f = 24808, τ f = 371 ppm/°C.
研究领域:
材料科学
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物理学
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DOI
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2021
·Vol. 127
·期 10
·1-9
·
IF 2.584
Meng Ke,Li Wenhua,Tang Xingui,Guo Xiaobin,Liu Qiuxiang,Jiang Yanping
Ferroelectric materials with the typical perovskite structure are widely used in capacitors, ultrasonic devices, oil drilling, transducers, and other fields. Lead-lanthanum-zirconium-titanate ceramics co-doped with Sn and Ba , have been widely investigated. However, there is little attention has been focused on the dielectric properties of barium-lanthanum-zirconium-titanate. Thus, in this work, Sn doped Ba 0.955 La 0.03 Zr 0.02 Ti 0.98 O 3 ferroelectric ceramics were prepared via a classical high-temperature solid state reaction. Scanning Electron Microscopy (SEM) was used to observe the surface appearance of ceramics. The X-ray diffraction (XRD) patterns at room temperature, indicate that the ceramics are well crystallized. Impedance properties and dielectric properties reflect the characteristic of typical high temperature dielectric relaxation behavior. The conductive activation energy and the relaxation activation energy are obtained through the calculation of the Arrhenius law. The fitting results show that the dielectric relaxation behavior at high-temperature, was related to the oxygen defect. The electrical modulus verified the partial short-range carrier migration, also contribute to the high-temperature dielectric properties.
研究领域:
材料科学
·
固态物理
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2017
·Vol. 29
·期 5
·3640-3647
·
IF 2.019
Guo Jingdong,Ma Weibing,Ma Minjie,Zhao Huaidang,Yang Yixuan,Gao Jifeng
Microwave dielectric properties and microstructures of ultra-low loss Li 2 Mg 3 TiO 6 ceramic prepared by reaction-sintering method (RS) and conventional solid-state reaction method (CS) have been investigated. The XRD patterns and SEM images revealed that the single phase of Li 2 Mg 3 TiO 6 and uniform morphology are obtained by both RS and CS methods at the optimal sintering temperatures. In order to further investigate the effects of different sintering methods on the microwave dielectric properties of Li 2 Mg 3 TiO 6 ceramics, the oxide polarizabilities and packing fraction were calculated based on the Rietveld refinement. The calculation results revealed that the RS method was more beneficial to the microwave dielectric properties of Li 2 Mg 3 TiO 6 ceramics in comparison with CS method. Excellent microwave dielectric properties for Li 2 Mg 3 TiO 6 ceramics with enhanced Q × f value of 157,036 GHz could be obtained using RS method sintered at 1250 °C for 6 h.
研究领域:
材料科学
·
陶瓷工程
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2018
·
IF 3.057
C.H. Yang,H.T. Wu
The Li 2 MgTi 1-x (Mg 1/3 Nb 2/3 ) x O 4 (0 ≤x ≤ 0.5) ceramics were prepared by the conventional solid-state method. The relationship among phase composition, substitution amount and microwave dielectric properties of the ceramics was symmetrically investigated. All the samples possess the rock salt structure with the space group of Fm- 3 m . As the x value increases from 0 to 0.5, the dielectric constant linearly decreases from 16.75 to 15.56, which can be explained by the variation of Raman spectra and infrared spectra. The Q·f value shows an upward tendency in the range of 0 ≤x ≤ 0.3, but it then decreases when x > 0.3. In addition, the temperature coefficient of resonant frequency ( τ f ) is shifted toward zero with the increasing (Mg 1/3 Nb 2/3 ) 4+ addition. By comparison, the Li 2 MgTi 0.7 (Mg 1/3 Nb 2/3 ) 0.3 O 4 ceramics sintered at 1400 °C can achieve an excellent combination of microwave dielectric properties: ε r = 16.19, Q·f = 160,000 GHz and τ f = −3.14 ppm/°C.
研究领域:
材料科学
·
物理学
✓ 已验证
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DOI
高影响因子
危险品化学品经营许可证（带存储）