JOURNAL OF THE AMERICAN CERAMIC SOCIETY
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2022
·Vol. 106
·期 3
·1954-1969
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IF 4.186
Yaxin Wei,Donglin He,Zhilong Fu,Yafei Liu,Ruifeng Wu,Wenyuan Li,Min Lu,Yahong Xie,Aimin Chang,Bo Zhang
Y 2/3 Cu 3 Ti 4 O 12 ceramic is a novel semiconductor with potential applications in electronic devices. However, its resistance drift and surface structure defects limit the application for negative temperature coefficient thermistor devices. A comparative study of solid-phase and a Pechini processing of Y 2/3 Cu 3 Ti 4 O 12 is presented in this paper, in the particular comparative study of stability. The Pechini method is found to be effective in lowering sintering temperature and improving thermal stability (Δ R / R 0 < 0.3％) in comparison with solid-phase method. The origin of the stability deterioration is related to the oxidation state of Cu ions and the migration of sublattice. The Pechini method overcomes stoichiometric ratio deviations and cation vacancy diffusion, thus reducing metal ion segregation in a continuous high-temperature environment and thereby showing unique insensitivity to oxygen. The important role of the Pechini method in improving thermal stability is revealed, which is expected to be used in the preparation of high stability electron devices.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
Energy & Environmental Science
·
2023
·Vol. 16
·期 12
·6046-6057
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IF 32.5
Haotian Gao,Kunpeng Zhao,Hexige Wuliji,Min Zhu,Beibei Xu,He Lin,Liting Fei,Hongyao Zhang,Zhengyang Zhou,Jingdan Lei,Heyang Chen,Shun Wan,Tian-Ran Wei,Xun Shi
High-entropy engineering is considered one of the most promising strategies in materials science, including the field of thermoelectrics. However, the presence of multiple elements with different atomic sizes and electronegativities in high-entropy materials often results in phase separation instead of the formation of a single phase. Herein, we propose that the adaptable sublattice can effectively stabilize single-phase high-entropy materials. Furthermore, the electrical and thermal transports can be efficiently tuned for much enhanced thermoelectric performance. Taking Mg2−δ(Si, Ge, Sn, Bi) as a case study, the loosely bonded Mg sublattice is featured with large dynamic adaptability or flexibility, enabling it to release the large lattice strains caused by the large atomic size mismatch among Si, Ge, Sn and Bi. The resulting ultralow lattice thermal conductivity of 0.58 W m−1 K−1 at 800 K is not only approaching the amorphous limit but also lower than that of all known Mg2X-based materials. Additionally, the interplay between the substitutional BiSn defects and self-compensational Mg vacancies leads to an optimized carrier concentration and thereby high power factors. A maximum zT value of 1.3 is finally realized at 700 K in Mg2−δSi0.12Ge0.13Sn0.73Bi0.02, which is among the top values of all Mg2X-based materials. This study highlights the role of an adaptable sublattice in stabilizing high-entropy materials and offers a new pathway for exploring high-performance thermoelectric materials.
研究领域:
材料科学
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热电材料
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晶体结构
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凝聚态物理
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能源转换技术
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Zihao Chen,Xiaolu Liang,Zimeng Pan,Zhenyu Wang,Yao Wang,Haitao Wang,Jiachen Wang,Jiankun Sun,Jun Ma,Xuexing Jiang,Jubo Peng,Xin Gu,Jing Zhang,Xiang Liu
In this study, La 0.67− x Nd x Ca 0.25 Sr 0.08 MnO 3 (LNCSMO, x = 0.09, 0.10, 0.11, 0.12) films were prepared by sol-gel spin coating method. The results indicate that the LNCSMO film is oriented and grown on a La 0.3 Sr 0.7 Al 0.65 Ta 0.35 O 3 (LSATO) (00 l ) substrate. In addition, with the increase of Nd 3+ content, the Mn-O bond length ( d Mn-O ) and Mn-O-Mn bond angle ( θ Mn-O-Mn ) decreases. The concentration ratio of Mn 4+ increases firstly and then decreases, and resulting in an enhanced and then weakened double exchange (DE) effect. Measuring the variation of sample resistivity with temperature ( ρ -T) using the standard four-probe method. As the content of Nd 3+ increases, the metal-insulator transition temperature ( T p ) gradually decreases, and the resistivity ( ρ ) gradually increases. The replacement of Nd 3+ makes the peak temperature coefficient of resistivity value ( TCR max ) of the material firstly increase and then decrease. At x = 0.11, the TCR max reaches 34.28 % K −1 at 254.72 K. This provides new insights into the impact of Nd doping on electrical transport properties.
研究领域:
材料科学
·
凝聚态物理
✓ 已验证
产品关联
DOI
高影响因子
Science Advances
·
2025
·Vol. 11
·期 27
·
IF 12.5
Shenghong Ren,Heyang Chen,Huangliu Fu,Haoran Huang,Tian-Ran Wei,Xun Shi,Xiuyan Li
Ductile polycrystals are usually metals with high-symmetry structures that provide multiple slip systems to coordinate the synergetic deformation of adjacent grains. However, while exceptional plasticity was recently discovered in a series of low-symmetry semiconductors, their deformation mechanism remains mysterious. Here, taking monoclinic Ag 4 SSe as a case study, we show that the inherent high-symmetry anion sublattice with a quasi–body-centered cubic (bcc) structure is embedded in the monoclinic matrix. This, coupled with the highly diffuse cations, results in multiple slip systems and is responsible for the superior plasticity as normally unexpected in low-symmetry structures. We observe typical slip systems conforming with those of the bcc structure by experiment. This finding clarifies the deformation mechanism of Ag 2 S-based low-symmetry semiconductors and sheds light on future exploration of ductile inorganic semiconductors.
研究领域:
材料科学
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固体物理
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半导体物理
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晶体学
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材料力学性能
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产品关联
DOI
PubMed
高影响因子
DALTON TRANSACTIONS
·
2022
·Vol. 51
·期 18
·7333-7342
·
IF 4.569
Hua Yu,Liuyan Zhou,Renguang Ye,Degang Deng,Shiqing Xu
Polychromatic emission can be achieved by controlling the distribution of the rare earth activator in multi-cation lattices, which can be used in the fields of white light LED and fluorescence temperature sensing. However, it is still a challenge to control their distribution and location of the target site in a given host material because the distribution of the rare earth activator is uncertain. In this paper, we have chosen Li4SrCa(SiO4)2 as the multi-cation site host and induced the distribution of Eu2+ ions between different cation sites through anion substitution, for the first time, to regulate the luminescence characteristics of a series of Li4SrCaSi2O8−yN2y/3:Eu2+ phosphors. In Li4SrCa(SiO4)2:Eu2+ phosphors, the substitution of O2− by N3− triggered a distinct ordered to disordered structure transition of the SiO4 tetrahedron and induced the remote distribution of the Eu2+ activator, which was verified through the analysis of the XRD, EPR, FT-IR and fluorescence spectra. Due to the location of Eu2+ ions in different cation sites (Eu2+Sr and Eu2+Ca), two distinguishable emission peaks with tunable color emissions and different responses to temperature were realized. The white LED that utilized blue-orange-emitting Li4SrCaSi2O4N8/3:Eu2+ and green-emitting BaSi2O2N2:Eu2+ (500 nm) displayed an outstanding color rendering index (Ra) of 85.1. Based on the fluorescence intensity ratio (FIR) technique, an optical temperature measurement mechanism was hypothesized and studied in the temperature range of 293–473 K. The highest Sa of the material was 0.086 K−1, and Sr was 1.76% K−1 based on the FIR detection technology, revealing obviously better than most inorganic optical temperature-measuring materials reported before. Our work indicates that Li4SrCaSi2O8−2yN4y/3:Eu2+ is a promising material for application in White LEDs and optical thermometers.
研究领域:
材料科学
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发光材料
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无机化学
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光电子学
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传感器技术
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Zimeng Pan,Jiachen Wang,Zihao Chen,Zhenyu Wang,Yao Wang,Xiaolu Liang,Haitao Wang,Yiliang Liu,Yufei Du,Jiamei Han,Jiabin Jiang,Xin Gu,Xiang Liu
For uncooled infrared bolometers, the traditional thermal sensing materials such as vanadium oxide and amorphous silicon have a relative low value of temperature coefficient of resistivity ( TCR ). In contrast, perovskite manganese oxide films exhibit 3–5 times higher TCR values than traditional materials. The important challenge is to achieve both high TCR and peak TCR temperatures ( T k ) at room temperature. Herein, La 0.7 Ca 0.3− x K x MnO 3 (LCKMO, 0.22 ≤ x ≤ 0.28) films were fabricated on La 0.3 Sr 0.7 Al 0.65 Ta 0.35 O 3 (00 l ) substrates using a combined sol–gel and spin coating process. It was found that by optimizing the K doping amount at x = 0.24, on the one hand, double exchange mechanism becomes the strongest. On the other hand, with minimal lattice strain, electron scattering is inhibited, and the electron-lattice coupling effect improves. Furthermore, the film exhibits a dense surface structure and a uniform distribution of grains. Finally, TCR value reaches 15.95 % K −1 at the corresponding temperature of 283.28 K. Obviously, the prepared LCKMO films effectively combine the high TCR of La 1− x Ca x MnO 3 with the high T k of La 1− x K x MnO 3 by optimizing the K doping level. The results show that LCKMO films are a promising candidate for fabricating uncooled infrared bolometers.
研究领域:
材料科学
·
凝聚态物理
·
电子器件
·
薄膜技术
·
红外传感
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）