POLYMER COMPOSITES
·
2020
·Vol. 41
·期 5
·1820-1829
·
IF 2.265
Yuliang Zhang,Kuan Yin,Kai Sun,Shengjia Cao,Fujun Tao,Binbin Wang,Li Li,Xueting Chang,Liangjun Huang,Runhua Fan
In recent years, random metacomposites with tunable negative permittivity have aroused widespread attention because of their distinctive properties and broad potential prospects. It is indicated that an enormously negative permittivity with a large value is not conducive to performance optimizing and impedance matching. In this article, the 2D Mxene Ti 3 C 2 T x was selected as the conductive phase instead of metal and carbon materials to fabricate Ti 3 C 2 T x /poly(vinylidene fluoride) metacomposites. The results of dielectric properties indicated that the conductive Ti 3 C 2 T x networks were formed by Ti 3 C 2 T x contacting with each other near the percolation threshold (ƒ c ). The as-obtained metacomposites containing 75 wt% Ti 3 C 2 T x generated percolating phenomenon. Additionally, when the fraction of Ti 3 C 2 T x was below ƒ c , the frequency dispersion behaviors of conductivity were in accordance with the Jonscher's power law, which proved that conducting mechanism was dependent on hopping conduction. While above ƒ c , the conductivity conformed to the Drude model and Lorentz model, which demonstrated a conductive behavior. Furthermore, the real part of permittivity transformed to negative value at 75 wt%, which can be explained as the existence of the low-frequency plasma oscillation and electric-dipole-induced resonance. The dielectric loss of the metacomposite was also analyzed by the imaginary permittivity spectra. Small negative permittivity values in the range of −550 to −400 were observed, owing to the low free carrier concentration in composites. The appearance of weakly negative permittivity opened up a new direction in negative dielectric materials by 2D layered Ti 3 C 2 T x nanomaterials.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
·
2025
·
IF 9.8
Haofei Sima,Bo Liu,Jingshi Liang,Xiaolin Shi,Chunling Zhang
Highly conductive and super-tough acrylamide hydrogels are essential for the development of flexible electronics. However, the inherent electrical and mechanical deficiencies of polyacrylamide (PAM) impede their utilization in flexible electronics. To address this challenge, a novel double-crosslinking method for rapid gelation based on an MXene-initiated poly (acrylamide/vinylimidazole) (MPAV) system is presented in this paper. MXene rapidly initiated the copolymerization of acrylamide with ionic liquids and acted as a physical cross-linking point for dynamic and reversible physical interactions with the polymer chains. The copolymerization of ionic liquids solved the problem of MXene aggregation in the medium and enabled the ionic conductivity mechanism of directional movement of free ions inside the MPAV hydrogel. MPAV hydrogels exhibited high electrical conductivity (2.28 S/m), excellent electromagnetic interference shielding efficiency (SE t > 35 dB), and sensitive strain sensing properties (maximum gauge factor: 14.69 and maximum sensitivity: 0.124 kPa -1 ). The well-designed MPAV double crosslinked hydrogel also displays remarkable mechanical properties (elongation: 457% and compressibility: 80%) and self-healing capabilities.
研究领域:
材料科学
·
柔性电子学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2024
·Vol. 35
·期 26
·1-13
·
IF 2.8
Gao Qin,Zhao Nianshun,Wu Jiale,Yu Qi,Wang Li,Hu Juan,Lu Sha,Zheng Xiaofan
The solid-state reaction method was employed to synthesize (1− x )[0.90NaNbO 3 –0.10Bi(Mg 0.5 Ta 0.5 )O 3 ]– x (Bi 0.5 Na 0.5 ) 0.7 (Sr 0.7 La 0.2 ) 0.3 Ti 0.9 Zr 0.1 O 3 , denoted as (1− x )(NN–BMT)– x BNSLTZ ( x BNSLTZ). XRD analysis of x BNSLTZ confirmed that all samples possessed a pure perovskite structure. SEM micrographs demonstrated homogeneous grain distribution and minimal porosity. With an increasing concentration of BNSLTZ, there was a gradual reduction in average grain size. Impedance spectroscopy was utilized to investigate the electrical properties of x BNSLTZ across a frequency sweep of 10 Hz–1 MHz and over a temperature range of 420–560 °C. The complex impedance and modulus spectra reveal non-Debye-type dielectric relaxation, indicative of two contributing mechanisms: grain and grain boundary effects on conduction. Electric modulus analysis indicated that the low-frequency relaxation process was temperature independent. The dc conductivity variation with temperature follows the Arrhenius equation. The ac conductivity was found to adhere to Jonscher power law. The E a (the relaxation activation energy) and E c (conductance activation energy) confirmed the relaxation mechanism of 0.3BNSLTZ is dipolar conduction. The dielectric properties showed a significant dependence on both frequency and temperature. A dielectric anomaly pointed to the presence of a single relaxation behavior. It was observed that an increase in BNSLTZ concentration led to a decrease in the maximum dielectric constant. Optimum performance was obtained with the 0.3BNSLTZ ceramics, which has the smallest average grain size (1.54 μm), considerable resistance value ( R ~ 1000 K \({\Omega }cm\) ), and moderate dielectric constant ( ε r ~ 600), superior to the pure NN-BMT ceramic. These results demonstrate that the electrical property of the x BNSLTZ ceramics have some potential value in the application of electrical materials.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
·
2020
·
IF 2.717
Dongyang Zhu,Yuan Xu,Xiaoxiong Wang,Jinxia Sui,Qi Liu,Chao Song,Jing Yu,Junpeng Wu,Yunze Long
We systematically studied the structure, electrical and magnetic properties of indium oxide prepared by electrospinning. Resistance studies have shown that indium oxide nanofibers have significant extrinsic effects. Magnetic studies have shown that indium oxide has obvious positive and negative magnetic resistance competition and transformation during temperature change. The conduction mechanism can be described using Mott’s variable range hopping conduction and the weak localization effect, where the dimensions of the conduction model are all in three dimensions.
研究领域:
材料科学
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凝聚态物理
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电磁学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2023
·Vol. 34
·期 24
·1-12
·
IF 2.8
Qu Jing-Jing,Liu Fei,Yuan Chang-Lai,Liu Xiao,Meng Liu-Fang,Shen Nai-Rui,Ning Hui-Wang,Jiang Wei
The Mn 3+ -ions doped Ba(Mn x Bi 1− x )O 3 ( x = 0.0, 0.02, 0.04, 0.06, 0.08 and 0.1) ceramic block samples are prepared by traditional solid-state method. The phase structures of these ceramic systems are analyzed, in which the XRD analysis results show the ceramic systems can be formed the solid solutions as the relatively lower Mn-adding content of x ≤ 0.4, and the ceramic blocks appear the additional diffraction peak belonging to the MnO 2 second phase with the increase of x value (≥ 0.6). Combined with the acceptor atom-doping conduction model theory and XPS analysis results, the main conductive forms of these Ba(Mn x Bi 1− x )O 3 thermistors include in the following three kinds: the movable holes formed by the acceptor Mn-doping, the 2Bi 4+ → Bi 3+ + Bi 5+ disproportionation reaction, and the [Mn 3+ /Mn 4+ ] small polaron jump. For the electrical properties test results, the NTC thermal properties for the x = 0.02 and x = 0.06 samples are relatively superior: ρ 25 − 690 Ω cm, B 25/85 − 3150 K and ρ 25 ~ 940 Ω cm, B 25/85 − 3080 K, respectively.
研究领域:
材料科学
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电子工程
✓ 已验证
产品关联
DOI
高影响因子
Small
·
2024
·
IF 13
Lin Zhang,Hongjing Shang,Qi Zou,Changping Feng,Hongwei Gu,Fazhu Ding
Flexible polymer/single-wall carbon nanotube (SWCNT) composites are a vital component for wearable/portable electronics, but the development of their n-type counterpart is laggard. Furthermore, little attention is paid to the interaction between SWCNT and polymers, especially the unconjugated polymers, as well as the conversion mechanism of conduction characteristics. Here, the n-type flexible SWCNTs/Polyvinyl Pyrrolidone (PVP) films are successfully fabricated, where the oxygen atoms in PVP interacted with SWCNT via hydrogen bonds, which can lower the energy barrier of electron tunneling, providing the pathway for the electron transfer. Furthermore, with the increasing synthesis temperature, the hydrogen bonds strengthened and the thermal activation energy further improved, both of which enhanced the electron-donating ability of PVP, resulting in a high-power-factor value of 260 µW m −1 K −2 . Based on the optimized SWCNTs/PVP films, a thermoelectric module is assembled, which achieved a power density of 400 µW cm −2 at a temperature difference of 56 K, coupled with excellent flexibility, showing a less than 1% variation of resistance after 5000 bending cycles. It shows the highest output-performance and the best flexibility among the reported SWCNT-based thermoelectric modules. This work provides significant insights into the interaction mechanism and performance optimization of hybrid thermoelectric composites, based on SWCNTs/unconjugated polymers.
研究领域:
材料科学
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纳米技术
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能源材料
✓ 已验证
DOI
PubMed
高影响因子
Cell Reports Physical Science
·
2023
·
IF 8.9
Chuan Shi,Jianjun Song,Yang Zhang,Xiuting Wang,Zhen Jiang,Tong Sun,Jinbao Zhao
Conductive filler-based solid polymer electrolytes are excellent candidates for the large-scale production of solid-state lithium-ion batteries. However, the transport and conduction mechanisms of lithium ions in such solid polymer electrolyte systems remain largely unrevealed. In this work, the results of in situ conductive atomic force microscopy demonstrate that lithium ions travel mainly through the Li 6.4 La 3 Zr 1.4 Ta 0.6 O 12 (LLZO) filler in polyethylene oxide (PEO)-based SPEs. The transport routes from LLZO into the polymer matrix can be greatly altered by adding succinonitrile (SCN). Combining experiment with ab initio simulations, we find that the adsorption affinity order for lithium ions is SCN > LLZO > PEO. Diffusion barriers are calculated for various composites, showing higher barriers for migration of lithium on the surface compared with in bulk. This work provides understanding of lithium affinity, diffusion barriers, and conductive mechanisms in solid polymer electrolytes, enhancing our understanding of mechanisms to guide future designs.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
ECS Journal of Solid State Science and Technology
·
2020
·Vol. 9
·期 5
·053003
·
IF 2.142
Hanying Wang,Chunyuan Deng,Kai Sun,Yunpeng Qu,Runhua Fan
In this paper, FeCrNi/CaCu3Ti4O12 metacomposites with different FeCrNi content were fabricated by low-temperature presureless sintering process. With increasing FeCrNi content above percolation threshold, the conduction mechanism changed from hopping conduction to metal-like conduction. Meanwhile, epsilon-negative property was obtained at 70 wt%–90 wt% content of FeCrNi, ascribing to the low frequency plasmonic state from three-dimensional conductive FeCrNi networks. The correlation between epsilon-negative property and inductive character was clarified by reactance spectrum. This work benefited the exploration of metal/ceramic metacomposites which could facilitate their promising applications in invisibility, high-k capacitors, novel antennae and sensors.
研究领域:
材料科学
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电磁学
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纳米技术
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·Vol. 48
·期 22
·33455-33461
·
IF 5.532
Yuyu Liu,Wenye Deng,Xianghui Chen,Yan Xue,Xuelian Bai,Huimin Zhang,Aimin Chang,Yongxin Xie
A series of novel high temperature negative temperature coefficient (NTC) composite ceramics based on (1- x )CaMn 0.05 Zr 0.95 O 3 - x NiMn 2 O 4 ( x = 0, 0.1, 0.2, 0.3) were fabricated by using the solid-state method. The Rietveld refinement method and backscattered electron (BSE) image confirmed the absence of any other phase. The conduction mechanism of the composite ceramics was determined by analyzing the complex impedance and resistance-temperature characteristics, which could be related to the formation of a continuous Mn 3+ -O-Mn 4+ network. The effect of spinel content on the high temperature stability was analyzed using aging tests. The ρ 400°C , ρ 700°C and B 400/700 values of the NTC thermistors were determined to be 4.9 × 10 6 –1.2 × 10 4 , 1.4 × 10 5 –0.8 × 10 3 Ω cm and 12739-5712 K, respectively. This indicated that the electrical properties could be tuned by adjusting the weight ratio of CaMn 0.05 Zr 0.95 O 3 and NiMn 2 O 4 . The findings obtained in this study reveal that the composite NTC thermistor exhibits a good application potential at high temperatures and under harsh environments.
研究领域:
材料科学
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无机非金属材料
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电子功能材料
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固态离子学
·
高温传感器技术
✓ 已验证
DOI
高影响因子
Materials Today Communications
·
2022
·
IF 3.662
Shuangfeng Wu,Chunchun Li,Huina Wei,Xingping Song,Laijun Liu,Jungu Xu
The tetragonal LiNbWO 6 (α−LiNbWO 6 ) with a trirutile structure was previously reported to have good lithium ion conductivity. However, the electrical properties of the hexagonal LiNbWO 6 (β−LiNbWO 6 hereafter) polymorph have not been reported yet mainly due to the difficulty to obtain single-phase. Herein, by quenching the sample from high temperature to room temperature at ambient air condition, a series of pure-phase β−LiNb 1- x Ta x WO 6 ( x = 0, 0.05, 0.1) materials were successfully prepared. The phase evolutions and conductivities of these materials were investigated by variable temperature X-ray diffraction and alternating current impedance spectroscopy techniques, respectively. The results revealed that lithium ion conduction also dominated in this hexagonal polymorph of LiNbWO 6 and an interesting great ionic conduction enhancement behavior was observed at a temperature region of 660–800 °C due to the minor phase transition from hexagonal to tetragonal. In addition, the possible ionic conducting mechanisms in both the tetragonal and hexagonal LiNbWO 6 materials were studied by the bond-valence-based method for the first time. The results disclosed two-dimensional and three-dimensional lithium ion migration pathways for the tetragonal and hexagonal LiNbWO 6 , respectively.
研究领域:
材料科学
·
电化学
·
固体化学
✓ 已验证
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2025
·
IF 19
Tianhong Zhou,Shuming Chen
Quantum dot light-emitting diodes (QLEDs) exhibit pronounced thermal- and size-dependent charge injection, characterized by significantly enhanced current under elevated temperatures and reduce device areas. In this study, the underlying mechanisms are elucidated by examining the influence of thermal energy on carrier transport dynamics. This analysis reveals that hole transport is governed by a hopping mechanism, leading to markedly increased hole mobility at higher temperatures, which is a primary contributor to the thermal-dependent current enhancement. This improved hole injection promotes better charge balance and increase luminance. Furthermore, both thermal effect and lateral resistance is identified as key contributors to the size-dependent current behavior. Smaller-area QLEDs exhibit reduced lateral resistance and more pronounced thermal effect, resulting in higher current injection. By leveraging these thermally and geometrically enhanced hole injection characteristics, the application of QLEDs is demonstrated as multi-dimensional visual temperature sensors and realize significantly stronger emission from high-energy excitonic state (1P) transitions in small-area devices.
研究领域:
光电子学
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纳米技术
·
量子点
·
半导体器件
·
电子器件中的热效应
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Electronic Materials
·
2023
·
IF 4.7
Qingyue Xu,Wenjing Li,Qi Qi,Ying Guo
Respiration is an important physiological signal that can be used to monitor human health and activity. This study presents a high-performance inorganic composite-based humidity sensor for respiration monitoring. The sensor is composed of a 3D nanostructure of ZnGa-layered double hydroxide (ZnGa-LDH) growing in situ on negatively charged MoS2 wafers, obtained by co-precipitation. By adjusting the MoS2 content, the resulting ZnGa-LDH/MoS2 composite displays a 3D “house of cards” structure with a larger surface area than pure ZnGa LDH or MoS2. The sensor exhibits nearly 3 orders of magnitude impedance change from the humidity range of 11% to 95% RH, fast response/recovery time of 1.5/5 s, hysteresis difference of 2.93%, and long-term stability and high repeatability. The optimized humidity sensor can distinguish between different breathing patterns, as well as the breathing rate/depth of the subject. The conductive mechanism of the material has also been analyzed by combining with the complex impedance curve of the material. This study not only provides an easy approach to adjust the hydrophilic/hydrophobic surface of the materials to control the humidity sensing ability but also develops a humidity sensor that can reflect the breathing conditions of the human body, potentially having applications in respiratory monitoring.
研究领域:
材料科学
·
纳米技术
·
传感器
·
生物医学工程
✓ 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）