RARE METALS
·
2025
·
IF 11
Mao Pu,Sun Jie,Feng Hui-Min,Liu Zhi-Yong,Guo Kun,Xie Bing,Wang Ting,He Li-Qiang,Gao Jing-Hui
Copper calcium titanate (CaCu 3 Ti 4 O 12 , CCTO) ceramics with colossal permittivity have gained widespread concern because of their potential application in modern electronic devices with miniaturization and integration. However, the extent of grain and grain boundary contribution to the colossal permittivity of CCTO-based ceramics based on the internal barrier layer capacitor (IBLC) model is still in debate. This affects their electrical performance optimization and real-world applications. In this study, a series of novel lead-free colossal permittivity ceramics, x LiCuNb 3 O 9 –(1– x )CaCu 3 Ti 4 O 12 (LCNO-CCTO), were designed and prepared using a solid-phase reaction approach. The colossal permittivity response mechanism of LCNO-CCTO ceramics was further explored by performing the complex impedance spectrum and analyzing the activation energy from the grain and grain boundary contribution viewpoint. As a result, the LCNO-CCTO ceramics present the cubic perovskite structure with the space groups of \(Im \overline{3}\) . All the LCNO-CCTO ceramics exhibit the significantly enhanced colossal permittivity (10 5 ) response, and the ceramic with x = 0.15 shows the highest permittivity of about 4.64 × 10 5 (20 Hz, room temperature) accompanied by a lower grain resistance of 9.61 Ω and larger grain activation energy of 0.21 eV. The enhanced colossal permittivity response is primarily attributed to the great electrical response inside grains of LCNO-CCTO ceramics, resulting from a smaller grain resistance. Also importantly, the high-frequency dielectric relaxation characteristics are improved by incorporating the LCNO into CCTO ceramics as an ion form. Accordingly, the LCNO-CCTO ceramics show a suppressed high-frequency dielectric loss. These results can provide a thorough knowledge and useful optimization strategy for developing high-performance colossal permittivity materials. Graphical
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
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2019
·
IF 4.029
He Lin,Wentao Xu,Haitao Zhang,Chen Chen,Youfu Zhou,Zhiguo Yi
We report on high dielectric constant (8.3 × 10 3 , 10 4 Hz), low dielectric loss (0.029, 10 4 Hz) as well as fine grain size (∼840 nm) achieved in pure CaCu 3 Ti 4 O 12 (CCTO) ceramics through a combination of sol–gel method, spark plasma sintering and annealing process. By adjusting the sintering temperature and annealing conditions, the composition variations, valence states and microstructures of CCTO ceramics are systematically studied, which provide direct clues in understanding the origin of their excellent dielectric response. Through the studies on the dielectric, impedance, modulus and conductivity properties of CCTO ceramics, a modified brick-layer model based on two interfacial polarizations originating from sub-grain boundary and grain boundary barriers is proposed to explain their dielectric behaviors. The high dielectric constant of CCTO ceramics is mainly dominated by the sub-grain contribution; and the reduced dielectric loss is attributed to the decreases of electrical conductivity and relaxation loss.
研究领域:
材料科学
·
电子材料
✓ 已验证
DOI
高影响因子
POLYMER COMPOSITES
·
2025
·
IF 4.7
Che Zhao,Yuxuan Zeng,Yuhan Zhou,Tianyu Wu,Meng Song,Lei Duan,Jiamei Dong,Yanlong Luo
Cross-linked polymeric damping materials with efficient energy dissipation mechanisms have attracted significant attention in impact protection applications. However, conventional viscoelastic damping materials frequently encounter limitations in processability and operational durability. Herein, a novel high-dielectric CaCu 3 Ti 4 O 12 /poly(lipoic acid) dynamic covalent network composite was introduced. This advanced material demonstrated an exceptional self-healing efficiency of 89.7% after 24 h at ambient temperature and remarkable reprocessability through thermally activated bond exchange reactions. Upon damage, the material's mechanical strength and integrity can be restored via the reformation of cross-linking points within the polymer network, thereby extending its operational lifespan. Notably, the synergistic combination of interfacial polarization effects from CaCu 3 Ti 4 O 12 particles and the dynamic equilibrium of coordination bonds establishes multiple energy dissipation pathways. This unique architecture achieves broadband damping performance with loss factors (tan δ) exceeding 0.3 across an extended frequency spectrum (0.009–100 Hz), coupled with a substantial enhancement in dielectric constant. The energy dissipation capability was verified through a steel ball rebound experiment, which demonstrated an exceptionally low rebound rate of 3.0%. This research offers an innovative design concept for developing sustainable impact-resistant materials. Highlights A novel high-dielectric self-healing CaCu 3 Ti 4 O 12 /poly(lipoic acid) damping material was successfully synthesized. The CaCu 3 Ti 4 O 12 /poly(lipoic acid) films exhibit outstanding self-healing ability and reprocessability. The CaCu 3 Ti 4 O 12 /poly(lipoic acid) composites achieve a superior impact resistance and a significantly elevated dielectric constant.
研究领域:
材料科学
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高分子化学
·
力学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Ruifeng Wu,Zhilong Fu,Yafei Liu,Yaxin Wei,Hao Sun,Aimin Chang,Bo Zhang
The entropy engineering strategy has been used for the first time to improve the grain boundary (GB) barrier of CaCu 3 Ti 4 O 12 (CCTO) ceramics, in order to solve its nonlinear problem at around 300 ℃ and expand its application in the field of high-temperature thermistors . To achieve this goal, we prepared (CaBaEuZnSr) 0.2 Cu 3 Ti 4 O 12 (CBEZSCT) high-entropy ceramics, and the GB spontaneous segregation properties were exploited to improve the GB resistance of CBEZSCT ceramics. The results show that the GB activation energy of CBEZSCT high-entropy ceramics (0.87 eV) is higher than that of CCTO ceramics (0.7 eV), which linearizes the resistance temperature curve and extends the application temperature limit from 300° to 750 °C. The proposed method of using a high entropy strategy to tune the GB resistance of CCTO to optimize its performance is highly effective, thus providing a new way of thinking about studying high-performance CCTO materials.
研究领域:
材料科学
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电子工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Meng-Han Yan,Zhi-Fei Zhang,Hai-Hua Huang,Zi-Liang Li,Peng Li,Ji-Gong Hao,Wei Li,Juan Du,Mahesh Kumar Joshi,Peng Fu
In this work, a series of x Sm 2 O 3 -(1- x ) CaCu 3 Ti 4 O 12 ( x Sm 2 O 3 -(1- x )CCTO, x = 0.00–0.05) negative temperature coefficient (NTC) ceramics were prepared by a solid-state method. The influence of Sm 2 O 3 content on electrical properties was examined using microstructural, band gap, morphological, Direct Current (DC) resistivity, and impedance spectroscopy analysis. The increase in Sm 2 O 3 content resulted in a gradual decrease of the resistivities ( ρ 25 ), thermal constants ( B 25/75 ), activation energies for electrical conduction ( E a ) and activation energies of the relaxation process ( E relax ) from 1.16 × 10 7 Ω cm, 6387 K, 0.5456 eV and 0.5592 eV to 3.43 × 10 5 Ω cm, 4149 K, 0.4088 eV and 0.4115 eV respectively. First-principles calculations revealed a reduction in the band gap by adding Sm 2 O 3 , partially explaining the decrease in electrical resistivity. In-situ XPS analysis elucidated a relationship between conduction mechanism of Sm 2 O 3 -doped CCTO ceramics and electron hopping. Impedance analyses showed that both grains and grain boundaries contributed to the NTC effect of ceramics. The electrical inhomogeneity arose from grains and grain boundaries, while local relaxation was due to the short-range motion of charge carriers.
研究领域:
材料科学
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物理学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2020
·Vol. 32
·期 1
·430-441
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IF 2.22
Liu Yuping,Wu Peng,Kang Peng,Li Liuyang,Shi Jinchao,Zhou Zheng,Chen Guang-xin,Li Qifang
With the development of new mobile communication systems, the composite substrate used for the wideband antennas will show a suitable dielectric constant, low dielectric loss, and good dielectric stability in a wide frequency range. In this work, a kind of dielectric filler, Sr 2+ -doped CaCu 3 Ti 4 O 12 nanowires (Ca 1− x Sr x Cu 3 Ti 4 O 12 NWs, x SCCTO NWs), was synthesized via a two-step hydrothermal method for the first time. The composites were then prepared by adding the obtained filler to polydimethylsiloxane (PDMS). Results revealed that Sr 2+ doping can significantly reduce the dielectric loss of composites and stabilize both the dielectric constant and the dielectric loss in a wide frequency range compared with those of CCTO NWs–PDMS composites. Moreover, 0.4SCCTO NWs–PDMS composites exhibit high thermal stability, tensile strength, breakdown strength, and energy density. These properties effectively broaden the frequency range of the PDMS based composites, which are very suitable for the application in flexible wideband antenna substrate materials.
研究领域:
材料科学
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电子工程
✓ 已验证
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2022
·
IF 6.364
Wentao Hao,Panpan Xu,Peide Han,Mingwen Wang
Reduction of dielectric loss for CCTO ceramics is a prerequisite for their applications. Considering internal barrier layer capacitance effect, improving the capacitance and grain boundary resistance is an effective way to reduce dielectric loss. Therefore, more conductive Ti 3+ and Cu + ions were introduced to grains by adding carbon to ceramic bodies, improving the permittivity of CCTO ceramics. Annealing was performed to increase the grain boundary resistance. The dielectric loss of the CCTO ceramics thus prepared, which maintain a giant permittivity, is significantly reduced. Specifically, the CCTO ceramic with carbon addition, which was sintered at 1080 °C for 8 h and air annealed at 950 °C for 2 h, exhibits a giant permittivity of about 2.50(5)×10 4 and a low dielectric loss of less than 0.050(2) from below 20 Hz to 50 kHz at room temperature. Meanwhile, its dielectric loss at 1–10 kHz is less than 0.050(2) from below room temperature to about 100 °C.
研究领域:
材料科学
·
电子材料
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Pu Mao,Qinzhao Sun,Lixue Zhang,Zepeng Wang,Liqiang He,Ruirui Kang,Gang Lu,Bing Xie,Zhiyong Liu,Jiping Wang
The development of excellent performances polymer-based nanocomposite films with high discharge energy density and high discharge efficiency are eagerly desirable for promoting their electric energy storage applications. However, the high discharge energy density and efficiency of polymer-based nanocomposite films are usually not compatible above intermediate electric fields. To address this issue, here we propose a newly designed multilayer-structured nanocomposite film with a combination of introducing the BaTiO 3 /CaCu 3 Ti 4 O 12 @SiO 2 (BT/CCTO@SO) hybrid nanoparticles with core–shell structure in middle layer and the poly(methyl methacrylate) (PMMA) linear polymer with low loss in outer layers. These motivations of introducing the core–shell structured hybrid nanoparticles with high dielectric constant and designing the multilayered structure give rise to an enhancement of maximum electric displacement while maintaining a relatively high breakdown strength. Also importantly, bring the PMMA polymer into top and bottom layers results in the low energy loss of whole nanocomposite film. Benefiting from these merits, a larger maximum electric displacement of 11.7 μC/cm 2 and a higher discharge energy density of 18.84 J/cm 3 accompanied with an ultrahigh discharge efficiency of 79.81% under an intermediate electric field of 418.13 MV/m are achieved in multilayer-structured nanocomposite film even at a very low filler loading of 2 wt% BT/CCTO@SO hybrid nanoparticles in middle layer, and these enhanced values are far higher than that of the monolayer nanocomposite films. This work validates the advantages of multilayered structure to integrate multiple components and presents outstanding overall performances of nanocomposite films in further applications of the dielectric capacitors with miniaturization and integration.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2022
·Vol. 33
·期 29
·22773-22784
·
IF 2.779
Chen Xin,Ouyang Yuting,Liu Xiukun,Ruan Hong,Xu Xu,Lu Shaorong,Li Yuqi
Providing a green and sustainable cathodic protection method for metal surfaces is the key to increasing the service life of equipment. Herein, furan-modified CaCu 3 Ti 4 O 12 (F-CCTO) and polyurethane with maleimide group as side group (MPU) were synthesized to prepare the high-performance dynamic covalent-crosslinked F-CCTO/MPU (FP) composites. And then the FP composites were further used to construct a triboelectric nanogenerator (FP-TENG) for Q235 steel cathodic protection. The results show that at 1-wt% F-CCTO content, the tensile strength and T 10% of the FP composite increased by 83.3% and 30 °C, respectively, compared with those of pure MPU. In addition, short-circuit current ( I sc ), open-circuit voltage ( V oc ), and peak power density of the FP-TENG were 4.6 μA, 100 V, and 3.3 Wm −2 , respectively. Notably, the mechanical and electrical output properties of the reprocessed FP composites obtained using the inverse Diels–Alder (DA) reaction are almost unchanged compared to the original FP composites. Electrochemical experimental results confirmed that the Q235 steel connected to the FP-TENG cathodic protection system exhibits excellent corrosion resistance. The corrosion potential of Q235 steel was reduced by about 110 mV, and in addition, the corrosion prevention mechanism of self-powered cathodic protection of metal surfaces was discussed.
研究领域:
材料科学
·
能源与环境
·
腐蚀与防护
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Xingyu Chen,Bo Zhang,Li Ni,Yang Zhou,Mingya Li,Aimin Chang
In this study, negative temperature coefficient (NTC) ceramics based on CaCu 3 Ti 4- x Zr x O 12 (0 ≦ x ≦ 0.15) compositions have been successfully synthesized by traditional solid-state method. X-ray diffraction results show that the major phase of all samples is CaCu 3 Ti 4 O 12 (CCTO) phase with body-centered cubic structure. The substitution of Zr 4+ for Ti 4+ inhibits the grain growth of CaCu 3 Ti 4- x Zr x O 12 ceramics and greatly reduces the grain size . The results of X-ray photoelectron spectroscopy fully confirm the coexistence of Cu + /Cu 2+ and Ti 3+ /Ti 4+ ions, which are one of the important reasons for conductivity of CaCu 3 Ti 4- x Zr x O 12 samples. There is a good linear relationship between the natural logarithm of resistivity and reciprocal temperature of all ceramic samples, which is consistent with NTC behavior. The obtained values of ρ 150 , B 150/550 and E a of the sintered samples are in the range of 1.62 × 10 5 –3.39 × 10 5 Ω cm, 6378–6593 K and 0.550–0.568 eV, respectively.
✓ 已验证
DOI
高影响因子
MRS Advances
·
2022
·Vol. 7
·期 30
·736-740
·
IF 0
Guo Yong,Tan Junlang,Zhao Jingchang
In this work, (La, Eu) co-doped CaCu 3 Ti 4 O 12 ceramics (Ca 1− x La x Cu 3 Ti 4− x Eu x O 12 (CLCTEO)), x = 0.1, 0.3, and 0.5) were prepared by the solid-state method. The phase structure, morphologies, dielectric properties, and impedance spectrum were investigated methodically. The XRD of CLCTEO ceramics confirmed the formation of the complex perovskite with a residual amount of CaTiO 3 . The refined calculation found that the lattice parameter of CLCTEO ceramics will significantly increase due to the co-doping of La and Eu. The FESEM analysis shows that the grain size of co-doped CCTO is smaller, reaching the nanometer scale. Impedance indicates that the (La, Eu) co-doped CCTO ceramics have higher dielectric permittivity than the single-doped with La or Eu. The results show that co-doping is an effective method to improve the dielectric properties of CCTO ceramics. Graphical abstract
研究领域:
材料科学
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电子工程
✓ 已验证
DOI
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
·
2019
·
IF 4.978
Tunmise Ayode Otitoju,Dafu Jiang,Yuanyuan Ouyang,Mohammed Ahmedelbadawi Mohammed Elamin,Sanxi Li
In this study, CaCu 3 Ti 4 O 12 (CCTO) modified polyethersulfone (PES) HF membranes were prepared via dry-wet phase inversion by adding different concentration of CCTO particles (0–4 wt.%) in the dope solution. The synthesized PES/CCTO composites were characterized by viscosity measurement , scanning electron microscope, X-ray diffraction, contact angle, pore size, and pore size distribution. The flux and the photocatalytic activity of CCTO entrapped PES membranes were subsequently evaluated by crossflow ultrafiltration and the photodegradation of Rhodamine B (RhB) under UV irradiation, respectively. The pure water permeability of the composite membranes improved considerably upon the addition of CCTO owing to its slightly improved hydrophilicity and moderate pore size. The results also show that the PES/CCTO composite exhibited a higher photocatalytic activity, which was mainly attributed due to the crystallite size of CCTO particles.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）