CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Wenyi Li,Feng Li,Xiaoming Qiu,Chuangchuang Gong,Min Jiang,Zhenxin Zhao,Xiaomin Wang
Owing to the intrinsic dielectric-magnetic coupling loss mechanism, perovskite-type lanthanide-transition metal oxide (LaTMO 3 ) is considered as a promising candidate for electromagnetic wave absorbing material, but unmodified LaTMO 3 suffers from limited polarization processes and weak super-exchange magnetic response. Herein, we manipulate the TM-O bond properties by regulating the configuration entropy of transition metal sites to address such issues within single-phase LaTMO 3 . Elaborate structural characterization and P-V-L bond theory demonstrate quantitatively the optimization of electromagnetic wave absorption performance mainly stems from the synergistic improvement in TM-O bond distortion degree and covalency, as well as the formation of diverse super-exchange pathways. Consequently, the high entropy La(Cr 0.2 Mn 0.2 Fe 0.2 Co 0.2 Ni 0.2 )O 3 exhibits a minimum reflection loss of −50.68 dB, an effective absorption bandwidth covering entire Ku band of 7.6 GHz. The radar cross section of the structure with La(Cr 0.2 Mn 0.2 Fa 0.2 Co 0.2 Ni 0.2 )O 3 coating are less than −10 dBm 2 within the incident angles -60-60°. This study contributes to a deeper understanding of design and preparation of efficient broadband electromagnetic wave absorbing materials.
研究领域:
材料科学
·
电磁学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Jiacheng Cao,Min Zhu,Xuefeng Lu,Faqi Zhan,Yuehong Zheng,Peiqing La
One of the key strategies for enhancing the thermoelectric figure of merit (ZT) is the simultaneous optimization of electron and phonon transport. In this work, (Sr 0.25 Ba 0.25 La 0.25 Pb 0.25 ) 1-x Nb 2 O 6-δ (0 ≤ x ≤ 0.15) ceramics were synthesized via the solid-state reaction method. By introducing a series of A-site defects into the high-entropy system, configurational entropy was modulated to optimize thermoelectric performance. As the value of x increased, both electrical resistivity and thermal conductivity exhibited significant reductions. Due to the synergistic effect of relatively high power factor (PF) and low thermal conductivity (κ), the sample with x = 0.1 achieved a peak ZT value of 0.19 at 1073 K, representing a 137.5 % enhancement over the stoichiometric ceramic sample. This research demonstrates that in the distorted tetragonal tungsten bronze structure, enhanced crystal symmetry facilitates electron delocalization, thereby improving electrical transport properties. Additionally, defects, including edge dislocations confirmed by scanning transmission electron microscopy analysis, increase the likelihood of random scattering events, leading to a reduction in lattice thermal conductivity. This study demonstrates that in (Sr 0.25 Ba 0.25 La 0.25 Pb 0.25 )Nb 2 O 6−δ high-entropy ceramics, the synergistic modulation of A-site defect concentration and configurational entropy effectively optimizes electron and phonon transport properties , thereby achieving a peak ZT value of 0.19.
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 THE EUROPEAN CERAMIC SOCIETY
·
2024
·
IF 5.8
Chufei Cheng,Ruixin Hao,Jiadong Hou,Fengnian Zhang,Fuhao Cheng,Ziqian Meng,Bei Ren,Yang Miao,Libiao Xin,Xiaomin Wang
In the thermal protection system of spacecraft, the bolts connecting the ceramic to the internal superalloy need to have low thermal conductivity and high strength . Two dense high entropy fluorite oxides (Zr 1/7 Hf 1/7 Ce 1/7 Y 2/7 La 2/7 )O 2-δ (ZHCYL) and (Zr 1/8 Hf 1/8 Ce 1/8 Y 1/4 La 1/4 Pr 1/8 )O 2-δ (ZHCYLP) were designed and synthesized by using the synergistic effect of plasma-assisted ball milling and spark plasma sintering(SPS). Through the synergistic effect of lattice distortion and oxygen vacancy guided by entropy regulation, ZHCYLP synthesized in this study has lower thermal conductivity(1.13 W·m −1 ·K −1 ), higher high temperature strength(192 MPa at 1000 °C) and high temperature phase stability up to 1600 °C than 8YSZ ceramics. The thermo-mechanical coupling finite element analysis results of high temperature bending test show that the variation trend of the maximum stress value of the sample is consistent with the experimental results. This shows that the mechanical and thermal properties of high entropy oxides can predict the variation trend of the maximum stress value in high temperature bending tests. It opens up a new way for designing and synthesizing high entropy oxide materials with low thermal conductivity and high strength which can be applied in the field of heat protection and load bearing.
研究领域:
材料科学
·
航天工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Jinxu Ma,Kepi Chen,Cuiwei Li,Xiaowen Zhang,Linan An
The valence-combination strategy was applied to design B-site substitution non-equimolar stoichiometric high-entropy perovskite oxides (HEPOs). 29, 56 and 29 valence combinations with the maximum configurational entropy higher than 1.5R for five-component HEPOs were identified when the average valence of B-site is 3, 4 and 5, respectively. Synthesis experiment was performed on 8 valence combinations with the average valence of B-site equal to 4. Single-phase HEPOs were obtained from 6 of them. It was also found that most of HEPOs have ordered structures. The formation of single-phase HEPO and ordered structure was discussed in terms of structural tolerance factor and valence-difference factor.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
iScience
·
2025
·
IF 4.1
Qingqing Cai,Rui Xu,Tao Wang,Lengyuan Niu,Yinyan Gong,Can Li
Medium-entropy compounds (MECs) have attracted significant interest thanks to their exceptional mechanical, physical and chemical properties, which are associated with their unique atomic structures. In this study, we enhanced the performance of MECs by optimizing their configurational entropy, leading to the formation of abundant quantum dots (QDs) and improved catalytic activity. This structural optimization not only adjusted electronic properties but also boosted catalytic performance and stability in oxygen evolution reactions (OER). MEC-Fe 2.0 catalyst demonstrated a low overpotential and outstanding long-term stability compared to others. Density functional theory simulations revealed that the incorporation of Co and Ni atoms increased the configurational entropy and facilitated the formation of short-range ordered QDs. This modification effectively lowered the chemical activity of Fe site, contributing to the enhanced catalytic performance. This design approach provides a promising strategy for advancing MEC, offering a pathway to improve their catalytic efficiency for various applications.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2025
·Vol. 108
·期 5
·e20355
·
IF 3.8
Liang Xu,Hongfei Gao,Xin He,Min Niu,Zhiwei Dai,Haotian Ni,Lei Su,Hongjie Wang
Ceramic thermal barrier coating (TBC) materials are used to protect the superalloys from the damage of harmful high-temperature airflow and improve the efficiency of jet and gas turbine engines. However, the long-term application of TBC materials and the robustness of these materials can be destroyed by aggressive calcium-magnesium-alumina-silicate (CMAS) melt during high-temperature service. Increasing the configuration entropy of material by doping multiple principal components has become a research hotspot in the design of corrosion-resistant thermal barrier coating material and has opened an infinite space of chemical composition, structure, and material properties. In this study, high-entropy (La 0.2 Sm 0.2 Er 0.2 Y 0.2 Yb 0.2 ) 2 Ce 2 O 7 was synthesized and its CMAS corrosion behavior was investigated by experimental investigation and first-principles calculation. The effects of the increase of configurational entropy and the subsequent potential effects on the CMAS corrosion behavior of Ce-based fluorite oxides have been sufficiently investigated. By compared with control samples, the high-entropy (La 0.2 Sm 0.2 Er 0.2 Y 0.2 Yb 0.2 ) 2 Ce 2 O 7 possesses the minimum infiltration depth of CMAS melts and the denser corrosion reaction layer, indicating the best corrosion resistance. The corrosion resistance mechanism of high-entropy (La 0.2 Sm 0.2 Er 0.2 Y 0.2 Yb 0.2 ) 2 Ce 2 O 7 was studied by first-principles calculation. The greater stability and resistance to segregation of CMAS melt in the CMAS/(La 0.2 Sm 0.2 Er 0.2 Y 0.2 Yb 0.2 ) 2 Ce 2 O 7 system, the poor adsorption capacity for CMAS melt which leads to a weak infiltration ability of CMAS melt; the weakest interfacial chemical reaction at the interface indicated by the smallest value of Griffith rupture work and the least species migration of high-entropy fluorite oxide can be responsible to the enhanced corrosion resistance. Our work reveals that increasing the configuration entropy can be an effective strategy for TBC material to enhance corrosion resistance.
研究领域:
材料科学
·
计算材料学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Peng Huang,Yifei Wang,Shengling Yuan,Hui Huang,Lijia Xu,Yongpeng Zhao
Metal oxides have attracted much attention due to their potential in electromagnetic wave absorption. However, the inherent energy dissipation capabilities of low-entropy metal oxides pose challenges in designing materials with optimal entropy levels. The regulation of entropy structure is anticipated to facilitate the development of novel electromagnetic functional materials featuring abundant active sites, adjustable specific surface area, stable crystal structure, unique geometric compatibility, and distinctive electronic structure. This study compared the electromagnetic loss performance of low, medium, and high entropy metal oxides in carbon matrices. As entropy increases, the number of phases expands, leading to enhanced interface polarization losses and improved impedance matching. However, further increases in entropy result in performance decline due to lattice distortions and mismatches in dielectric constant and magnetic permeability. Experimental data and theoretical analysis reveal that performance enhancement in medium-to high-entropy metal oxides is attributed to their unique morphology and the synergistic effects of multiple metal components, which enhance interfacial and defect polarization mechanisms. Heterogeneous interfaces and lattice defects provide additional polarization sites, aiding in the conversion of electromagnetic energy into heat. The presence of intermediate phases effectively absorbs and dissipates electromagnetic waves, thereby enhancing the overall absorption capability.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
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
·
功能陶瓷
·
介电材料
·
固态化学
✓ 已验证
DOI
高影响因子
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
·
2025
·
IF 4.2
Kuan Li,Longfu Li,Lingyong Zeng,Yucheng Li,Rui Chen,Peifeng Yu,Kangwang Wang,Zaichen Xiang,Tian Shang,Huixia Luo
Medium/high-entropy alloys (MEAs-HEAs) and rhenium-based compounds with a non-centrosymmetric (NC) structure have received a lot of attention for offering a fertile soil in search for unconventional superconductivity. Here, five previously unreported NC Re-based MEA-HEA superconductors with an α-Mn lattice are successfully synthesized, with their superconducting transition temperatures (Tcs) ranging from 4 to 5 K. An increase in the superconducting transition temperature (Tc) can be achieved by modulating the valence electron count (VEC) through compositional adjustments. Magnetization measurements confirm that all the synthesized Re-based MEA-HEAs are bulk type-II superconductors. Specific heat analysis reveals that the superconducting state of these HEAs can be well described by a single-gap s-wave model. Our results show that the Kadowaki-Woods ratio (KWR) of these α-Mn MEA/HEA superconductors are close to the typical value of heavy fermion compounds, suggesting the existence of strong electronic correlation. These findings provide promising material platforms to study the role of high disorder in the origin of superconductivity in the NC MEAs-HEAs.
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
Journal of Materials Chemistry A
·
2025
·
IF 9.5
Chenyang Duan,Hao Zhang,Zhiwei Hu,Zhenya Li,Wenjie Bian,Chao Jing,Jian-Qiang Wang,Linjuan Zhang
Modulating the configurational entropy of materials is an effective strategy to develop efficient and robust electrocatalysts for the oxygen evolution reaction (OER) in clean energy technologies. However, the impact of configurational entropy on catalytic activity has received limited attention. In this study, we systematically investigate a class of alloy catalysts composed of Cr, Mn, Fe, Co, and Ni, as a function of Ni content to modulate the configurational entropy to 1.50R (high-entropy alloy, Ni-HEA), 1.23R (medium-entropy alloy, Ni-MEA), and 0.66R (low-entropy alloy, Ni-LEA), where R is 8.314 J (mol−1 K−1). In situ Raman spectroscopy reveals that increased configurational entropy facilitates the formation of the OER active γ-NiOOH phase on the alloy surface. This transition leads to a significant decrease in the OER overpotentials and Tafel slopes. The optimized Ni-HEA exhibits an overpotential of only 217 mV at 10 mA cm−2, and demonstrates prolonged operational stability for 600 hours under industrial conditions. This work enhances our understanding of the impact of configurational entropy on catalytic activity and offers a novel approach for the rational design of porous high-entropy catalysts with improved OER efficiency.
研究领域:
材料科学
·
电化学
·
清洁能源技术
✓ 已验证
产品关联
DOI
高影响因子
RARE METALS
·
2025
·
IF 11
Li Bo-Kang,Fu Lv-Ping,Gu Hua-Zhi,Huang Ao,Yang Shuang
High-temperature industries, as the primary consumers of energy, are greatly concerned with energy savings. Designing refractory linings with low thermal conductivity to reduce heat dissipation through high-temperature furnace linings is a critical concern. In this study, a series of novel entropy-stabilized spinel materials are reported, and their potential applications in high-temperature industries are investigated. XRD and TEM results indicate that all materials possess a cubic spinel crystal structure with the \(Fd\overline{3} m\) space group. Furthermore, these materials exhibit good phase stability at high temperatures. All entropy-stabilized spinel aggregates demonstrated high refractoriness (> 1800 °C) and a high load softening temperature (> 1700 °C). The impact of configurational entropy on the properties of entropy-stabilized spinel materials was also studied. As configurational entropy increased, the thermal conductivity of the entropy-stabilized spinel decreased, while slag corrosion resistance deteriorated. For the entropy-stabilized spinel with a configurational entropy value of 1.126 R , it showed good high-temperature stability, reliable resistance to slag attack, and a low thermal conductivity of 2.776 W·m −1 ·K −1 at 1000 °C. Graphical abstract
研究领域:
材料科学
·
高温工业
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2024
·
IF 3.5
Le Fu,Bohan Wang,Fuqing Jiang,Wenjun Yu,Wei Xia
Solid-state reaction (SSR) is frequently used to fabricate bulk high-entropy ceramics (HECs). However, a high temperature and a long dwelling time are typically required to allow the occurrence of SSR. Meanwhile, conventional HECs were typically composed of single-phase solid solution with micrograins. It is of great interest to develop nanocrystalline dual-phase HECs under mild conditions. Here, we fabricated entropy-mediated crystalline-amorphous dual-phase ceramic nanocomposites, and the fabrication process showed significantly higher energy and time efficiency than the conventional SSR. The nanocomposites were composed of entropy-mediated nanoparticles (EM-NPs) embedded in an amorphous SiO 2 matrix. The constituent elements were homogeneously distributed in the EM-NPs at the atomic level. The EM-NPs were dislocations-free but with lattice strain, and they showed a strong coarsening tendency during annealing. The nanocomposites showed a significant solid solution hardening effect. The reported results would provide useful guidance to fabricate nanocrystalline HECs with crystalline-amorphous dual-phase microstructure.
研究领域:
材料科学
·
纳米技术
✓ 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）