JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2020
·Vol. 31
·期 17
·14879-14885
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IF 2.22
Niu Shuting,Jiang Juan,Wang Jinzhao,Gan Lin,Zhang Tianjin
0.67CaTiO 3 –0.33LaAlO 3 (CTLA) microwave dielectric ceramic materials with the additives of H 3 BO 3 , Li 2 CO 3 or H 3 BO 3 –Li 2 CO 3 were prepared by a conventional solid-state reaction method. The effects of the sintering additives on the densification behavior, phase compositions, microstructures, and microwave dielectric properties of the CTLA ceramic samples were investigated. It was found that the binary additive of H 3 BO 3 –Li 2 CO 3 effectively promoted the densification and lowered the sintering temperature of the CTLA ceramic samples without a significant decrease in their Q × f values. For example, with an addition of 0.2 wt% H 3 BO 3 –0.1 wt% Li 2 CO 3 , the optimal microwave dielectric properties of ε r = 45.5, Q × f = 31,771 GHz and a near-zero τ f of 2.43 ppm/℃ were obtained in the CTLA ceramic sample sintered at only 1175 ℃, which is significantly lower (~ 225 ℃) compared to the sintering temperatures of conventionally sintered CTLA ceramics.
研究领域:
材料科学
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电子材料
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DOI
高影响因子
Materials
·
2025
·Vol. 18
·期 21
·4932
·
IF 3.2
Yangyang Zhang,Haizhou Guo,Shuyao Zhai,Liqin Yue,Juqin Zhang,Suxia He,Ruiling Fu,Chiyu Yin,Ling Zhang
(Bi 0.5 Na 0.5 )TiO 3 -based lead-free ferroelectric ceramics are among the most extensively researched energy storage materials today. In this paper, (1 − x)Bi 0.46 Sr 0.06 Na 0.5 TiO 3−x CaTiO 3 ceramics were synthesized through a solid-phase sintering method by synergistically adjusting CaTiO 3 components after introducing Sr 2+ at the A-site. The XRD patterns revealed that all samples formed a single perovskite solid solution, with the 111 and 200 peaks shifting to higher levels as the CaTiO 3 increased, indicating a gradual decrease in cell volume. The SEM images exhibited dense crystals without any apparent porosity, which were formed by the different components of the ceramics. Through energy storage, dielectric, and charge–discharge performance tests, it was found that with a 10%mol CaTiO 3 addition, the samples obtained a maximum breakdown field strength of 260 kV/cm and corresponding saturation polarization strength of 32.80 μC/cm 2 and thereby exhibited a reversible energy storage density valued 3.52 J/cm 3 . In addition, the dielectric constant varied by less than 10% within the temperature range of 63.7 °C to 132.7 °C and presented good frequency (10–250 Hz) stability at 180 kV/cm. Moreover, the ceramics demonstrated a maximum current density reaching 349.58 A/cm 2 and a maximum power density of 18.90 MW/cm 3 for their charge–discharge performance, all of which makes them suitable for pulse system applications.
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DOI
PubMed
高影响因子
Nature Communications
·
2025
·Vol. 16
·期 1
·1-9
·
IF 15.7
Cai Jinghan,Lan Shun,Wei Bin,Qi Junlei,Nan Ce-Wen,Lin Yuan-Hua
Dielectrics with high permittivity, low dielectric loss, and good temperature stability are crucial for electronic components to meet the ever-increasing application demands. However, challenges remain in further optimizing dielectric properties due to the correlation between these parameters. Here, we propose a chemical bonding engineering strategy in high-entropy CaTiO 3 ceramics and realize colossal permittivity with low loss and excellent stability. Our results reveal that the high-concentration oxygen vacancy ( \({{{\rm{V}}}}_{{{\rm{O}}}}^{\cdot \cdot }\) )-related defects and the decreased activation energy of grain/grain boundary led to a colossal permittivity dielectric behavior, which should be ascribed to the weakened chemical bonding and the reduced formation energy of defects confirmed by our first-principles calculation. Consequently, in the high-entropy CaTiO 3 ceramic, a permittivity of 2.37 × 10 5 , low loss of 0.005, and good temperature stability (<± 15%) in -50–250 °C are simultaneously achieved. This finding implies that chemical bonding engineering may be a promising strategy for designing colossal permittivity materials and provides a broad opportunity for the development of other defect-dependent functional materials.
研究领域:
材料科学
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电子工程
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DOI
PubMed
高影响因子
ACS Applied Energy Materials
·
2023
·
IF 6.4
Jianbo Li,Quanwei Jiang,Zhen Tian,Huijun Kang,Zongning Chen,Enyu Guo,Zhiqiang Cao,Tongmin Wang
Manipulating microstructures is of considerable importance for controlling the transport of heat and charge. Herein, the microstructure of CaTiO3 was controlled by adding Nb. Nb serves a dual purpose in the matrix by acting as a dopant, providing extra electrons, and as a phonon scatterer in the lattice. Additionally, it precipitates as a second phase in the Nb-doped CaTiO3 matrix. Through this approach, we achieved significant enhancements in the power factor, which increased from 2.81 μW cm–1 K–2 in pristine CaTiO3 to 7.67 μW cm–1 K–2 in CaTi0.85Nb0.15O3 at 1031 K. Additionally, we observed a reduction in the lattice thermal conductivity from 2.61 W m–1 K–1 in pristine CaTiO3 to 2.46 W m–1 K–1 in CaTi0.85Nb0.15O3 at the same temperature. As a result, a noteworthy 180% improvement in the overall zT was achieved. Remarkably, the zT value of CaTi0.9Nb0.1O3 in our work was found to be 88% higher than the values reported in the existing literature at 1031 K. This work provides a reference for optimizing the thermoelectric properties of CaTiO3-based materials by precipitating metal inclusions.
研究领域:
材料科学
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热电学
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陶瓷材料
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固体物理
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DOI
高影响因子
Advanced Electronic Materials
·
2025
·
IF 5.3
Jian Wang,Zhuowen Zou,Jiajun Zhu,Dandan Gao,Wanbiao Hu
The wealth of complex defects induces attractive functionalities and structural variations in materials. This renders engineering defect states, as well as building up a defect-property relationship, a central subject, but it remains highly challenging because the configurations and charge dynamics of the involved defect systems are hardly explored and thus unclear experimentally. Herein, the defect-dipole-cluster in La-doped CaTiO 3 and, more importantly, its dielectric response process is clarified. Through combined HAADF-STEM, DFT calculation, dielectric, and photoluminescence (PL) spectroscopy, the defect configuration is identified to be V Ca − O − − La Ca type defect-cluster-dipole. The electron–hole recombination from the Ti 3+ and O − states dominates the dielectric relaxation process, as revealed by the similar relaxation frequencies of dielectric response and photoluminescence emission. These findings experimentally demonstrate property tailoring involved in defect-cluster-dipole, providing crucial insights for establishing the defect-property relationship in dielectric materials.
研究领域:
材料科学
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凝聚态物理
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电子显微学
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DOI
高影响因子
POWDER TECHNOLOGY
·
2022
·
IF 5.64
Hong-Rui Yue,Gong-Jin Cheng,Jian-Xing Liu,Xiang-Xin Xue,Wei-Jun Zhang
Calcium ferrite-TiO 2 (C x F-TiO 2 ) diffusion couples were prepared to investigate the reaction between TiO 2 and CaO of calcium ferrite during sintering vanadium‑titanium magnetite. The distribution, species, and number of phases in the vicinity of the C x F/TiO 2 interface were characterized by electron probe microanalysis (EPMA), Fourier transform-infrared (FT-IR) spectroscopy, and X-ray diffraction (XRD) that could select the scanning location. The phases generated from the C x F side to the TiO 2 side are 66.66% CaFe 2 O 4 + 33.33% Fe 2 O 3 , 100% CaTiO 3 , 66.66% CaTiO 3 + 33.33% Fe 2 O 3 , and 75% CaTiO 3 + 25% Fe 2 O 3 , respectively. The isothermal section was plotted using the experimental data. The diffusion thickness decreased from 90.2 to 8.1 μm as the temperature decreased from 1323 to 1173 K, and increaesed from 47.4 to 121.4 μm as the annealing time increased from 1 to 4 h. The linear relationship between the diffusion thickness and the square root of the annealing time indicates that the formation of CaTiO 3 was controlled by the diffusion process. Vacancy-mediated diffusion mechanism, which was widely used to describe the diffusion-controlled process, was introduced to describe the formation of CaTiO 3 in the vicinity of the C x F/TiO 2 interface. The Ti 4+ in the TiO 2 layer jumped and diffused through the Ti 4+ vacancies in the CaTiO 3 + Fe 2 O 3 layer to the CaFe 2 O 4 + Fe 2 O 3 /CaTiO 3 interface, and reacted with CaFe 2 O 4 and O 2− to generate CaTiO 3 . The concentration data across the C x F/TiO 2 interface were applied in the modified Boltzmann-Matano method to calculate the interdiffusion coefficient. The average interdiffusion coefficients of various Ti concentrations increased with temperature: 2.51 × 10 −10 , 7.49 × 10 −10 , 2.56 × 10 −9 , and 8.06 × 10 −9 cm 2 ·s −1 at 1173, 1223, 1273, and 1323 K, respectively. The relationship between the logarithm of the interdiffusion coefficient and the reciprocal of the temperature was empirically described by the Arrhenius expression. Linear regression analysis showed that the diffusion activation energy of CaTiO 3 formation is 300.14 kJ/mol.
研究领域:
材料科学
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冶金学
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DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2017
·
IF 9.446
Ruinan Wang,Shuang Ni,Gang Liu,Xiaoxiang Xu
In this work, we have applied microstructure management and doping techniques to conventional wide band gap semiconductor CaTiO 3 with the aim to improve its light absorption and photocatalytic activity. A series of La/Cr co-doping hollow CaTiO 3 cubes have been successfully prepared by a template-free hydrothermal method. Their crystal structures, microstructures, optical absorption and photocatalytic hydrogen production have been systematically investigated. Our results suggest that hollow CaTiO 3 owns a higher light absorption than solid one and demonstrates a much better photocatalytic activity both under full range (λ ≥ 250 nm) and visible light illumination (λ ≥ 400 nm). These improvements probably originate from the peculiar hollow microstructures that increase photon-matter interactions and shorten the charge migration pathways. The photocatalytic activity for hydrogen production has been further studied by varying the La/Cr content in CaTiO 3 . An optimal doping point at 5% La/Cr doping level has been reached for full range illumination with apparent quantum efficiency approaching ∼2.41%. Nevertheless, the activity under visible light illumination shows a clear dependence on doping level with highest apparent quantum efficiency ∼0.40% at 20% La/Cr doping level. DFT calculations reveal the critical role of Cr in forming a new spin-polarized valence band inside the original band gap of CaTiO 3 therefore is responsible for band gap reduction and visible light photocatalysis. This work here highlights the importance of microstructure control to the photocatalytic performance and shall shed a light on the design and development of efficient photocatalytic materials/systems.
研究领域:
材料科学
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光催化
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能源化学
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无机功能材料
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半导体物理
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纳米结构材料
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DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2026
·Vol. 109
·期 4
·e70709
·
IF 4.2
Quanwei Jiang,Zhibin Chen,Zhen Tian,Jianbo Li,Xiaowei Shi,Huijun Kang,Zongning Chen,Enyu Guo,Tongmin Wang
Calcium titanite, as an eco-friendly thermoelectric material, offers great potential for thermoelectric power generation. However, the polar metal–oxygen bonds place a low ceiling on the electrical conductivity, thereby limiting the overall thermoelectric performance. In this work, high-purity Ca 1- x Pr x Ti 0.95 Nb 0.05 O 3 ( x = 0–0.20) compounds are synthesized to investigate the electrical and thermal transport features. Nb doping enhances bond covalency, as confirmed by electron localization function (ELF) and crystal orbital Hamilton population (COHP) analyses. This enhancement leads to high carrier mobility by weakening the electron–phonon coupling, a mechanism verified by direct electron–phonon coupling calculations. Meanwhile, the multiscale hierarchical architectures, including dual point defects, nanoprecipitates, dislocations, etc., originating from the large mass and strain field fluctuations, further reduce the lattice thermal conductivity close to the minimum value estimated from Cahill's model. A peak ZT value of 0.33 is acquired for Ca 0.90 Pr 0.10 Ti 0.95 Nb 0.05 O 3 at 1073 K, approximately 267% higher than that of the pristine CaTiO 3 sample. Our investigation highlights that weakening the carrier–phonon coupling by modulating chemical bonding is a reasonable strategy, which could be applied in other thermoelectric systems.
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高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Changshuai Shu,Jiachen Xi,Chongyang Li,Wangfeng Bai,Peng Zheng,Peng Li,Jiwei Zhai
Constructing relaxor ferroelectrics (RFEs) in dielectrics is an efficient approach to break the so-called inverted relations between recoverable energy storage density ( W rec ) and efficiency ( η ). However, in view of the requirement for energy conservation, the major challenge of realizing near-zero energy consumption (ultrahigh η ) accompanied with high W rec still remains in the field of dielectric energy storage. Here, we designed a linear-like RFE with directly induced short-range local polar nanoregions via incorporating the ferroelectric into linear dielectric to realize high-performance capacitive storage, especially near-zero energy loss. Benefiting from linear-like RFE design, the combination of enhanced breakdown strength, ultrasmall dielectric loss, and minimized polarization hysteresis synergistically contributes to a record-high η of ∼97.7 % with a high W rec of 5.87 J/cm 3 and ultrahigh figure of merit of 255, which is ahead of most recently reported state-of-the-art lead-free ceramics. Moreover, based on such linear-like RFE merits, high thermal/frequency stability and cycling durability with high η > 90 % of the designed ceramics expand their applications in harsh condition energy storage systems. This study demonstrates the superiority of linear-like RFE design and provides a referential paradigm towards developing advanced near-zero energy loss energy storage dielectrics.
研究领域:
材料科学
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能源存储
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·Vol. 47
·期 22
·31329-31336
·
IF 4.527
Dehua Wang,Hongwei He,Xiaoxiong Wang,Yang Yu,Longlong Jiang,Ye Lu,Jing Yu,Jun Zhang,Yunze Long,Keqing Ruan
Traditional inorganic materials exhibit rigidity owing to the lack of polymer chains in polymer materials or atom slipping in metals. However, nanometerization has been recently proposed for the conversion of inorganic oxide materials into flexible materials. Herein, the flexible inorganic luminescent material , CaTiO 3 :0.2%Pr 3+ , was synthesized through electrospinning, and the macroscopic flexibility of pure inorganic CaTiO 3 :0.2%Pr 3+ was achieved. The flexible membrane was characterized via X-ray diffraction, thermogravimetry , scanning electron microscopy (SEM), and photoluminescence analyses. The grain size was analyzed at various calcination temperatures via SEM, and the results suggested that the increase in the calcination temperature resulted in the growth of crystal grains. Studies have reported that the growth of crystal grains is beneficial for improving the luminescence performance; however, to obtain better flexibility, smaller crystal grains are required. This study provides an important reference for the design of flexible inorganic materials.
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DOI
高影响因子
INORGANIC CHEMISTRY COMMUNICATIONS
·
2022
·
IF 3.428
Mengjie Lu,Siyu Liu,Jinyan Xiong,Wei Li
Photocatalytically splitting water to hydrogen production is a great potential for addressing the issue of energy crisis and environmental pollution. Metal-semiconductor hybrid photocatalyst has attracted increasing attention, and especially non-noble metal decoration is one of promising strategies to promote photoinduced electron-hole pairs separation for an efficient solar-to-hydrogen evolution. Herein, a facile solvothermal approach was successfully employed to prepare calcium titanate (CaTiO 3 ) nanorods with decoration of copper particles. The composition and morphology characterization showed that the Cu particle was deposited on the surface of CaTiO 3 nanorod. The as-synthesized CaTiO 3 /Cu composites exhibited promoted solar-to-hydrogen performance and their activities varied from copper loading amounts. The optimized CaTiO 3 /Cu-0.05 achieved a hydrogen evolution rate of 251 µmol g −1 h −1 , which was much higher than that of bare CaTiO 3 . Based on the photoluminescence spectra and photocurrent density measurements, it was proposed that efficient separation of photogenerated charges was achieved between the CaTiO 3 nanorod and Cu nanoparticles, which promoted water splitting for H 2 production. This work further confirms that metallic Cu decoration is an efficient approach to promote photocatalytic H 2 production performance of semiconductor photocatalysts.
研究领域:
材料科学
·
能源科学
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DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2020
·
IF 4.495
Jiawei Zhang,Jian Wang,Dandan Gao,Huan Liu,Jiyang Xie,Wanbiao Hu
Ceramic-based capacitors for energy storage devices require simultaneously high energy density and efficiency. Achieving high electric breakdown field based on linear dielectrics is crucial. Here, A-site Sm 3+ doped perovskite Ca 1-1.5 x Sm x □ 0.5 x TiO 3 ceramics with introduced A-site vacancies ( V A ) were prepared. All Ca 1-1.5 x Sm x □ 0.5 x TiO 3 ceramics crystallize in an orthorhombic structure, with lattice constants a , b , and c linearly decreased. As a result of Sm 3+ dopants and V A , the grain size decreased while the ceramics’ density was improved. The permittivity decreases from 176 ( x = 0) to 135 ( x = 0.1), but tan δ is effectively constrained (∼10 −4 ). What’s more, the dielectric breakdown strength is significantly improved from 429 kV/cm ( x = 0) to 547 kV/cm ( x = 0.1) with dielectric linearity is maintained. The optimum energy storage density of 2 J/cm 3 ( x = 0.02) with ultrahigh energy efficiency of over 93.7 % is achieved, which are superior to many existing linear dielectrics and relaxor ferroelectrics. This work confirms the energy-storage enhancement through chemical modifications and microstructural engineering.
研究领域:
材料科学
·
能源存储技术
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DOI
高影响因子
危险品化学品经营许可证（带存储）