CERAMICS INTERNATIONAL
·
2024
·Vol. 51
·期 6
·6968-6975
·
IF 5.1
Xinrong Yang,Deqin Chen,Guobin Zhu,Siyu Xiong,Xiaowei Zhu,Laijun Liu,Chunchun Li
The impact of configurational entropy on the microwave dielectric properties of LnNbO 4 fergusonite was investigated by designing a series of high-entropy counterparts, including (La, Nd, Sm, Ho, Yb, Y)NbO 4 (6RNO), (La, Nd, Sm, Eu, Ho, Yb, Y)NbO 4 (7RNO), (La, Nd, Sm, Eu, Gd, Ho, Yb, Y)NbO 4 (8RNO), and (La, Nd, Sm, Eu, Gd, Ho, Tm, Yb, Lu, Y)NbO 4 (10RNO). Simply prepared by the solid-state route, a pure phase with a monoclinic fergusonite structure of space group C /2 c was obtained. By comparing the microstructural evolution and lattice vibration modes, an analysis was conducted on the variations in microwave dielectric performances. It was confirmed that the permittivity ( ε r ) is primarily influenced by relative density, while the quality factor ( Q × f ) exhibits a strong correlation with packing fraction and lattice vibrations. The resonant frequency temperature coefficient (τ f ) is significantly associated with bond valence. The optimal microwave dielectric properties were achieved in 7RNO ceramics at a temperature of 1270 °C, resulting in a relative density of 95.43 %. The microwave dielectric properties were measured as ε r = 18.62, Q × f = 35200 GHz, τ f = −23.28 ppm/°C. The present study expands the application of entropy engineering to achieve ultrahigh configurational entropy in microwave dielectric ceramics . These findings demonstrate that optimizing the configuration entropy is an effective approach for manipulating the dielectric properties, thereby providing valuable insights for material component design.
研究领域:
材料科学
·
无机非金属材料
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功能陶瓷
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介电材料
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固态化学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2025
·
IF 8.2
Xi Ouyang,Manwen Yao,Tongqing Yang,Xi Yao
The significance of temperature stability in piezoelectric materials is crucial as it directly impacts their reliability and consistency in piezoelectric performance under varying temperature conditions. However, the relationship between structural stability and temperature stability remains ambiguous. In this study, we aim to address this issue by constructing piezoceramics with low and high structural stability using the “high configurational entropy” (Pb (Ni0.11Hf0.33Ti0.34Nb0.22) O3) strategy and “tolerance factor” (Pb (Ni0.11Hf0.21Ti0.46Nb0.22) O3) strategy. The relationship between structural stability and temperature stability was then explored through temperature-dependent XRD, Raman, and piezoelectric property tests in the range of 25–250 °C. Our results successfully demonstrate a positive correlation between structural stability and temperature stability. The microstructure information analyzed by temperature-dependent XRD and Raman showed that Pb (Ni0.11Hf0.33Ti0.34Nb0.22) O3 has a more abundant phase structure transition and higher ion disorder, which is directly reflected in its poor temperature stability in the piezoelectric property tests. On the other hand, Pb (Ni0.11Hf0.21Ti0.46Nb0.22) O3 exhibited excellent temperature stability due to its stable phase structure and lower ion disorder. Specifically, the unipolar strain of piezoceramics with low structural stability decreases from 1.63% at 25 °C to 0.24% at 200 °C, while the unipolar strain of piezoceramics with high structural stability only changes from 0.78% at 25 °C to 0.79% at 225 °C. Additionally, our understanding of the high energy barrier imposed by a wide band gap, as well as the hindrance of domain switching and stabilization of domains through the pinning effect of defect dipoles, reveals the underlying mechanism of temperature stability. These findings provide a promising approach to the development of piezoceramics that can effectively function across a wide range of temperatures.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2024
·
IF 5.8
Qianbiao Du,Jianhong Duan,Linzhao Ma,Longxiang Jiang,Hao Li
The novel spinel Li 2 Zn 6 MgTi 6 O 20 ceramic with high configuration entropy was synthesized using the traditional solid-state method. Analysis from X–ray diffraction, transmission electron microscope, and Raman spectra demonstrates a disordered state in Li 2 Zn 6 MgTi 6 O 20 ( Fd -3 m ). This dense ceramic exhibits excellent microwave dielectric properties at 1240 °C: ε r = 18.01 ± 0.2, Q × f = 98,450 ± 3,000 GHz (at 9.17 GHz), and τ f = −38 ± 3.6 ppm/°C. Further studies combining bond valence and P–V–L theory reveal that Ti 4+ significantly influences the ε r of Li 2 Zn 6 MgTi 6 O 20 ceramic, while the Ti 4+ polarizability is underestimated by 10.6%, resulting in the ԑ r higher than the ԑ th . The solid solution leads to structural disorder and high configuration entropy, driving each bond to contribute almost equally to the bond energy. This structural feature promotes a favorable and stable microstructure, enhancing the microwave dielectric and sintering properties synergistically. Furthermore, the τ f is optimized by composites ( 4.5 ppm/°C).
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Man Tian,Hujun Cao,Laijun Liu,Jungu Xu
In this work, a series of multiple lanthanide and tungsten co-doped fluorite structured (Bi 2 O 3 ) 0.95- x (Ho 0.4 Er 0.4 Tm 0.4 Yb 0.4 Lu 0.4 O 3 ) x (WO 3 ) 0.05 ( x = 0.1, 0.2, 0.3, 0.4) and (Bi 2 O 3 ) 0.26 (Ho 0.5 Er 0.5 Tm 0.5 Yb 0.5 O 3 ) 0.48 (WO 3 ) 0.26 materials were prepared by traditional solid-state reaction method. The phases, stabilities, and electrical properties of these materials were thoroughly studied. The results revealed that under high oxygen partial pressure, CO 2 , or inert atmospheres, all these samples had excellent long term thermal stability and chemical stability, and the samples of (Bi 2 O 3 ) 0.95- x (Ho 0.4 Er 0.4 Tm 0.4 Yb 0.4 Lu 0.4 O 3 ) x (WO 3 ) 0.05 ( x = 0.1, 0.2, 0.3, 0.4) with low or mediate configuration entropies showed pure and high oxide ion conductivities, e.g. ∼2.6 × 10 −2 S/cm at 600 °C for the sample x = 0.2. Whereas, for the (Bi 2 O 3 ) 0.26 (Ho 0.5 Er 0.5 Tm 0.5 Yb 0.5 O 3 ) 0.48 (WO 3 ) 0.26 sample with high configuration entropy, pure ionic conduction occurred only within a narrow temperature range (700−750 °C) under the N 2 atmosphere. Under strong reducing condition, only the high-entropy sample (Bi 2 O 3 ) 0.26 (Ho 0.5 Er 0.5 Tm 0.5 Yb 0.5 O 3 ) 0.48 (WO 3 ) 0.26 showed high phase and chemical stabilities, but would introduce strong electronic conduction rise from the reduction of the high content W 6+ . While for (Bi 2 O 3 ) 0.95- x (Ho 0.4 Er 0.4 Tm 0.4 Yb 0.4 Lu 0.4 O 3 ) x (WO 3 ) 0.05 with low or mediate configuration, phase decompositions with impurities of Bi metal and HoH 2 were observed under strong reducing atmosphere, accompany with obviously decreased conductivities. Therefore, we provided here a comprehensive understanding for the multiple components doped Bi 2 O 3 -based materials with configuration entropy from low to high on their phases, stabilities, and electrical properties, and suggested a new strategy for designing and stabilizing bismuth-oxide-based materials.
研究领域:
材料科学
·
固体化学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2025
·
IF 7.9
Chenhui Bai,Yuxiu Yao,Saeed Ahmed Khan,Jing Li,Fang Yi,Jie Zhang,Hu Shi,Hulin Zhang
Thermogalvanic cells provide an efficient pathway for converting low-grade heat into electricity. Their performance is governed by the Seebeck coefficient, which dictates voltage output and thermoelectric efficiency. Previous efforts to enhance the Seebeck coefficient have focused on entropy contributions from solvent-induced solvation effects, while the impact of configurational entropy in quasi-solid-state networks has received limited attention. Here, we demonstrate that configurational entropy serves as an additional factor modulating the thermoelectric behavior of thermogalvanic hydrogels. Using the PVA hydrogel incorporating the Fe 2+ /Fe 3+ redox couple as a model system, we elucidate how constrained polymer networks alter redox thermodynamics. When a Fe 2+ /Fe 3+ concentration of 0.1 mol L −1 , the Seebeck coefficient in the hydrogel reaches 1.32 mV K −1 , significantly higher than that in aqueous solution (0.75 mV K −1 ). Complementary molecular dynamics simulations further demonstrate that hydrogel chains disturb the first solvation shell, broaden the radial distribution of coordinating water molecules, and increase dipole orientation disorder, thereby amplifying the configurational disparity between oxidized and reduced species. This leads to an enhanced role of configurational entropy in the ionic migration entropy. Our findings therefore highlight rational design ideas for optimizing high-performance quasi-solid-state thermogalvanic cells by quantifying the actual contribution of configurational entropy in the nano-network structure.
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Xuan Zhou,Xiaojun Yang,Hui Li,Peng Zhang
High-entropy rare-earth zirconates (RE 2 Zr 2 O 7 ) have attracted considerable attention as thermal barrier coatings (TBCs) candidates. In this study, pyrochlore RE 2 Zr 2 O 7 (RE = Nd, Sm, Eu, Gd, Dy) ceramics were synthesized with a fixed average RE 3+ radius while varying configurational entropy by tuning the number of principal cations. The ceramics were synthesized and systematically examined to assess the effect of entropy on thermo-mechanical properties. With increasing entropy, the thermal conductivity and the coefficients of thermal expansion of the entropy engineering designed RE 2 Zr 2 O 7 are improved, attributable to enhanced anharmonicity from elemental mixing, which leads to lattice distortion and a high density of dislocations. These features intensify phonon scattering and strengthen the Grüneisen response. Fracture toughness is also enhanced owing to increased energy dissipation during crack propagation via dislocation interactions. This work highlights configurational entropy engineering as a general route to tune thermo-mechanical properties for promising TBC top coat candidates.
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2025
·
IF 19
Lvye Dou,Xianglei Pu,Bingbing Yang,Chi Zhang,Yujun Zhang,Wei Xu,Lei Li,Jianqiang Li,Hui Wu,Ce-Wen Nan,Yuan-Hua Lin
Ceramics possess notable attributes including high-temperature stability, strong chemical tolerance, and exceptional wear resistance, rendering them highly promising for various applications. Nevertheless, the brittleness of ceramics presents a substantial hurdle in harnessing their full potential for applications in wearable devices and unconfined loading environments. In this study, an entropy-assisted strategy is proposed to realize the flexibility of Bi 4 Ti 3 O 12 -based dielectric nanofibers. The findings illustrate that augmented atomic configurational entropy within the nanofibers instigates favorable structural changes, including the development of refined grains and a substantial amorphous component, thereby leading to the notable improvement in the flexibility of ceramic nanofibers with functional properties. The flexible high-entropy nanofibers enable the development of a high-performance capacitive strain sensor with remarkable response sensitivity (1.62 kPa −1 ), wide temperature range adaptability over 25–350 °C, and excellent fatigue resistance over 3000 cycles. Importantly, this entropy-driven approach holds promise for the advancement of flexible functional ceramics, extending beyond simple oxides such as amorphous silica and alumina.
研究领域:
材料科学
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纳米技术
·
传感器
·
陶瓷
·
柔性电子学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2024
·
IF 8.1
Chao Huang,Qiang Li,Liping Sun,Lihua Huo,Hui Zhao,Fourcade Sebastien,Bassat Jean-Marc
High entropy oxides are one of the research topicalities in the field of SOFC. However, the relationship between configuration entropy and the electrochemical properties of these materials is not well understood. Here, a medium entropy material (La 0.2 Pr 0.2 Nd 0.2 Sm 0.2 Eu 0.2 ) 2 CuO 4 ((Ln 0.2 ) 2 CuO 4 ) derived from Nd 2 CuO 4 material is designed. It was found that increasing the configuration entropy of the A-site promotes the production of highly reactive/concentrated non-stoichiometric oxygen and increases the covalency of the Cu3d-O2p orbital. The polarization impedance of (Ln 0.2 ) 2 CuO 4 is 0.92 Ω cm 2 at 700 °C, which is smaller than that of Nd 2 CuO 4 (1.8 Ω cm 2 at 700 °C). The peak power density of single cells NiO-YSZ|YSZ|GDC|cathode is 526 mW cm −2 at 700 °C within 60 h of stable operation at 0.5 V. First-principles calculations demonstrate that (Ln 0.2 ) 2 CuO 4 has lower charge transfer energy, which promotes the electronic conduction. Furthermore, the dissociation energy of adsorbed oxygen (O ad ) on the surface of (Ln 0.2 ) 2 CuO 4 is 2.24 eV, which is smaller than that of Nd 2 CuO 4 (2.26 eV). These results suggest that the entropy-increasing strategy can enhance the electrocatalytic performance.
研究领域:
材料科学
·
电化学
·
能源材料
·
固态离子学
·
催化化学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2025
·
IF 6.9
Xiang Xu,Jingxu Tian,Zijie Sun,Kueasook Ratchadaporn,Peng He,Zheng Zeng,Liqing Li
The expensive material costs of precious metals long limit their use as catalysts. The development of High-Entropy Alloy (HEA) materials provides a feasible approach to combine high performance and lower cost. Therefore, Ru-containing HEA nanoparticles are synthesized on carbon nanofibers. Among them, Ru 0.2 @CNFs reveals the best catalytic oxygen evolution reaction (OER) performance and extraordinary stability for the 1000th cycle. Moreover, the Ru-containing multimetallic catalyst models are calculated based on crystal information obtained from X-ray diffraction result. The great electrocatalytic potential of the Ru 0.2 <1 1 1> crystal face is indicated by the density of states and d-band center, which might benefit from the stronger atomic interaction caused by high-entropy mixing. The largest configuration entropy of Ru 0.2 HEA (1.58 R ) gives a reasonable explanation for its remarkable stability in OER electrocatalysis. In addition, the similar adsorption energies of *OH demonstrate the abundant active sites on the surface of RuFeCoNiCu HEA. As a result, the high-entropy material Ru 0.2 @CNFs can provide potential nanocatalysts with reduced noble metal loading for practical applications. Besides, significant insights for performance prediction in other high-entropy materials are given by the modeling and calculations of HEAs.
研究领域:
材料科学
·
催化
·
纳米技术
·
电化学
·
计算化学
✓ 已验证
产品关联
DOI
高影响因子
RARE METALS
·
2025
·
IF 11
Feng Lei,Meng Yu-Ying,Chen Yi-Zhong,Zhu Ze-Kai,Zou Yi-Ming,Zhang Wen-Biao,Xiang Chun-Yan,Liu Er-Kang,Chen Deng-Jie,Tang Yi,Voiry Damien,Gao Qing-Sheng
Single-phase high-entropy carbides (HECs) are emerging as promising electrocatalysts for the hydrogen evolution reaction (HER) due to their widely tunable electronic configurations and the synergistic effects of multimetallic sites. However, their controllable synthesis and mechanistic understanding remain significant challenges due to the thermodynamic immiscibility of the multi-metallic elements within the carbide structure. In this study, we demonstrate the first successful synthesis of single-phase HECs based on Mo and W systems through an innovative high-entropy design strategy. Guided by comprehensive thermodynamic predictions, the single-phase solid solution formation temperatures were determined for the HEC- n ( n = 2–9) series of high-entropy carbides. We achieved the configurational-entropy driven formation of HEC nanoparticles containing 4–9 transition metal elements via an ultra-fast joule heating process (i.e., (TiZrHfVNbTaCrWMo)C). Through rapid synthesis and screening, we obtained (VNbCrWMo)C nanoparticles exhibiting the best HER activities and exceptional long-term stability over 168 h due to high-entropy composition design and synthesis strategies, outperforming unary, binary, ternary, quaternary carbides and carbides with more than six metallic elements. Theoretical calculations and X-ray photoelectron spectroscopy analysis reveal that the (VNbCrWMo)C high-entropy carbide achieves enhanced HER activity through multi-metallic synergy, where constituent elements cooperatively redistribute electron density at catalytic sites. This work provides a new pathway for the rational design of advanced metal carbide electrocatalysts, highlighting the potential of high-entropy effects in tailoring material properties for energy conversion applications. Graphical abstract
研究领域:
材料科学
·
电化学
·
纳米技术
·
能量转换
·
催化
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Xi Ouyang,Yushan Deng,Manwen Yao,Xi Yao
The traditional approach to designing ferroelectrics through phase boundaries has limitations in regulating polarization configuration and achieving significant performance enhancements. In contrast, the concept of high-entropy materials has emerged as a promising strategy for designing new materials with enhanced properties. Herein, by incorporating the high configurational entropy ( S config ) strategy, the investigation explored the influence of S config on the electrical properties of PNN-PHT piezoceramics. The results demonstrated that high S config values were highly beneficial in improving the piezoelectric properties and significantly influenced the microstructure and grain size. The increase in S config value was found to be positively correlated with the Rayleigh coefficient ( α ), dielectric loss (tan δ ), and frequency dispersion ( γ ), while inversely correlated with the coercive electric field ( E c ). By exploring the mechanism via Raman and simulation analyses, it was discovered that high S config induces enhanced disorder, increased lattice distortion, and sharp volume changes. This ultimately resulted in a richer phase structure, reducing the potential energy barriers and leading to a lower activation energy ( E a ) required for polarization switching. This finding provides novel strategies and directions for the development of high-voltage and high-coercive-field materials, holding promise for designing piezoelectric devices with enhanced power density and precision.
研究领域:
材料科学
·
铁电学
·
固体物理
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纳米技术
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电子陶瓷
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2023
·Vol. 11
·期 36
·19696-19706
·
IF 11.9
Xiaolan Duan,Xiaopeng Wang,Lan Xu,Tingting Ma,Yuan Shu,Shengtai Hou,Qiang Niu,Pengfei Zhang
Since 2018, high entropy oxides (HEOs) have been introduced to the catalysis community, due to their tunable compositions, abundant lattice distortion, and excellent thermal stability. Although porous structure is usually essential for heterogeneous catalysts, the synthesis of porous HEOs using both traditional hard and soft templates failed. Herein, inspired by the self-assembly behavior of polystyrene (PS), various HEOs with three-dimensional ordered macro-porous (3DOM) structure, including cubic Ce0.5Ni0.1Mg0.1Cu0.1Zn0.1Co0.1Ox, cubic Zr0.5Ni0.1Fe0.1Cu0.1Mn0.1Co0.1Ox, spinel Ni0.2Mg0.2Cu0.2Mn0.2Co0.2Al2Ox, and perovskite LaNi0.2Fe0.2Co0.2Cr0.2Mn0.2Ox, were prepared. Together, the uniform distribution of metal precursors inside the PS matrix and the decreased crystallization temperature due to the increased configuration entropy facilitated the formation of 3DOM-HEOs. The crystallization process was monitored by in situ X-ray diffraction. Interestingly, Ce0.5Ni0.1Mg0.1Cu0.1Zn0.1Co0.1Ox with ordered macropores, active oxygen species, and high entropy-stabilized structure exhibits competitive activity (T50 = 393 °C) in soot combustion under harsh conditions (4.2 vol% moisture, 20 ppm SO2), higher than those of the sol–gel control sample (T50 = 419 °C), 3DOM-CeO2 (T50 = 506 °C), commercial CeO2 (T50 = 519 °C) and 1% Pt/Al2O3 (T50 = 595 °C).
研究领域:
材料科学
·
催化
·
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）