Nanoscale
·
2024
·Vol. 16
·期 45
·21031-21038
·
IF 5.8
Hanwen Hu,Yiyan Liao,Shanshan Tan,Chen Li,Jun Tang,Kun Zheng,Lei Yang
Ag2Se has emerged as a promising n-type thermoelectric material; however, its application is limited mainly due to the strongly coupled charge carrier and phonon transport. Enhancing phonon scattering by constructing interfacial complexes often results in low carrier mobility due to its strong carrier scattering resulting from the high energy barrier at the multiphase interface. Inspired by the cell membrane with selective permeability, we construct bio-mimic grain boundaries with TiO2 and MoS2 co-decoration in Ag2Se to decouple electron scattering from strong phonon scattering. The nanostructured TiO2 with a high dielectric constant screens the interfacial Coulomb potential, ensuring efficient carrier transport and reducing the grain boundary barriers, while the few-layer MoS2 provides significant phonon scattering to further reduce the thermal conductivity. This method effectively enhances the zT value of Ag2Se by as much as 60% and also can significantly enhance the theoretical output performance of the thermoelectric device, which highlights the effectiveness of the bio-mimic grain boundary engineering strategy.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2021
·Vol. 32
·期 13
·18397-18407
·
IF 2.478
Gao Yan,Li Ling,Li Yule,Yang Sheng’an,Ma Ji,Li Yingjuan,Qi Longfei,Yang Yunrui,Wu Dingzhang,Zhang Hui,Chen Qingming
Doping is a primary method to improve the temperature coefficient of resistance ( TCR ) and magnetoresistance ( MR ) of La 1- x A′ x MnO 3 polycrystalline in a low magnetic field. La 0.7 Ca 0.3- x Na x MnO 3 ( x = 0, 0.02, 0.04, 0.06, 0.08) series of polycrystalline were synthesized by the sol–gel method. X-ray diffraction patterns indicate that the crystal structure changes from orthorhombic to rhombohedral, and the space group changes from Pnma to \(\text{R}\stackrel{\mathrm{-}}{\text{3}}\text{c}\) with increasing x . With Na-doping rise, the increase in grain size reduces grain boundaries, weakening the electron scattering at grain boundaries and decreasing the peak resistivity. The excellent MR (59.51%) is observed in La 0.7 Ca 0.24 Na 0.06 MnO 3 at the 1 T magnetic field. Meanwhile, TCR max reaches 12.36% K −1 in the absence of a magnetic field. The resistivity variation with temperature curve fitting illustrates that grain boundary scattering dominates in the low-temperature stage, and the effect of activation energy dominates in the high-temperature stage.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
NPG Asia Materials
·
2022
·Vol. 14
·期 1
·1-11
·
IF 10.761
Jian Gang,Jiao Yong,Feng Liang,Meng Qingzhen,Yang Ning,Zhu Shangtao,Lü Minfeng,Wong Ching-Ping
Dielectric substances exhibit great potential for high-power capacitors due to their high stability and fast charge–discharge; however, a long-term challenge is to enhance energy density. Here, we propose a poly(vinylidene fluoride) (PVDF) composite utilizing BaTiO 3 nanoparticle@TiO 2 nanosheet (BT@TO ns) 2D nanohybrids as fillers, aiming at combining the interfacial strategy of using a core–shell filler and the electron scattering of a 2D filler to improve the energy density. With 4 wt% filler, the composite possesses the largest breakdown strength ( E b ) of 561.2 MV m −1 , which is significantly enhanced from the 407.6 MV m −1 of PVDF, and permittivity of 12.6 at 1 kHz, which is a 23% increase from that of PVDF. A superhigh energy density of 21.3 J cm −3 with an efficiency of 61% is obtained at 550 MV m −1 . The 2D BT@TO ns-filled composite exhibits a higher energy density than composites filled with core–shell 1D BT@TO nws or non-core–shell 0D BT, 1D TO, or 2D TO particles. The E b and energy density improvements are attributed to the buffer layer-based interface engineering and enhanced area scattering of electrons caused by the 2D hybrids, an effect similar to that of a ping-pong paddle to scatter electric field-induced charge migrations in composites. Thus, an effective hybrid strategy is presented for achieving high-performance polymer composites that can be used in energy storage devices.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Yiliang Liu,Xiaolu Liang,Yufei Du,Yao Wang,Zihao Chen,Zhenyu Wang,Haitao Wang,Xin Gu,Jiankun Sun,Jing Zhang,Xiang Liu
The influence of sintering duration ( t s = 7, 10, 13 and 16 h) on the microstructure, A-site cation disorder ( σ 2 ), hopping conduction mechanism and temperature coefficient of resistance characteristics of La 0.81 Sr 0.19 MnO 3 polycrystalline ceramics were investigated in this work. By systematically adjusting the sintering duration, it is observed that the A-site cation disorder has decreased from σ 2 = 4.23 × 10 −3 ( t s = 7 h) to σ 2 = 3.71 × 10 −3 ( t s = 13 h). The changes in the A-site cation disorder increase the ratio of Mn 4+ /Mn 3+ , Mn-O bond lengths and angles of perovskite manganite oxides. The hopping conduction mechanism of the ceramics was examined using the variable range hopping model, and the result verified that the dynamics of charge carriers are significantly impacted by variations in cation disorder. All of the scattering processes in electron-electron, electron-phonon, and electron-magnon in La 0.81 Sr 0.19 MnO 3 ceramics were decreased with cation disorder decreasing. The temperature coefficient of resistivity ( TCR ) achieved its maximum value of 11.19 % K −1 at room temperature (298.56 K) when t s = 13 h. The value of TCR has increased by 38.32 % from 8.05 % K −1 ( t s = 10 h) to 11.19 % K −1 ( t s = 13 h). Therefore, the ceramic has great application potential for infrared bolometers.
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 Materials Chemistry C
·
2025
·
IF 5.1
Sidi Fan,Xinghan Du,Wenqi Zhang,Kaixuan Sun,Rui Yang,Fangcheng Lü,Qing Xie,Xiang Yu
To optimize the dielectric properties of poly(m-phenylene isophthalamide) (PMIA), nanodiamond (ND) particles are incorporated as doping fillers. However, they often cause issues like uneven dispersion, filler aggregation, interfacial incompatibility, and dielectric mismatch. To address these issues, three coupling agents of (3-Aminopropyl)triethoxysilane (KH550), triethoxyvinylsilane (KH151), and nonafluorohexyltriethoxysilane (F-agent) are utilized to modify ND. Among them, the F-agent modified PMIA/ND composite film shows the best performance, achieving a Young’s modulus of 5.8 GPa and a breakdown strength of 342 kV/mm at 15 wt% doping. The F-agent enhances the ND dispersibility due to an increased Zeta potential, effectively mitigating filler agglomeration. Its fluorine-containing functional groups engage in robust hydrogen bonding with PMIA molecules, strengthening interfacial interactions and compatibility. This promotes a dense and compact structure conducive to a uniform electric field distribution and confines dipole activities for a reduced dielectric loss. Moreover, the negative surface potential of the F-agent induces repulsive Coulomb interactions with free electrons, leading to the carrier scattering effect that shortens the mean free path of electrons and impedes charge transport. Therefore, the leakage current is highly suppressed for a high breakdown strength. These findings provide valuable insights and guidelines for designing high-performance aramid-based dielectric composites.
研究领域:
材料科学
·
电气工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）