JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Wenchao Lin,Pengrong Ren,Yuhui Wan,Shu Yang
BaTiO 3 , Ba(Ti 0.2 Zr 0.2 Sn 0.2 Hf 0.2 Nb 0.2 )O 3 , SrTiO 3 , Sr(Ti 0.2 Zr 0.2 Sn 0.2 Hf 0.2 Nb 0.2 )O 3 , (Sr 0.5 Ba 0.5 )TiO 3 and (Sr 0.5 Ba 0.5 )(Ti 0.2 Zr 0.2 Sn 0.2 Hf 0.2 Nb 0.2 )O 3 ceramic samples were prepared using a traditional solid-state reaction method. XRD analysis shows that all the samples are a single-phase perovskite structure. After the addition of B-site high-entropy components Sn 4+ , Zr 4+ , Hf 4+ , and Nb 5+ in BaTiO 3 , the permittivity and dielectric loss decrease significantly, and the temperature stability of the permittivity is remarkably improved. Compared with the undoped sample, the insulation resistance of the high-entropy ceramic sample increases exponentially. The incorporation of high entropy components changes the conduction mechanism, improves the insulation performance, and significantly decreases thermal conductivity, which improves the adiabatic performance of ceramics. These results demonstrate that the high entropy strategy can significantly influence the electrical and thermal properties of BaTiO 3 and SrTiO 3 -based ceramics. Our work provides a new idea for the modification of functional ceramic materials and offers new promising candidates of dielectrics applied for Class-I type ceramic capacitors.
研究领域:
材料科学
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电子工程
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产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2024
·Vol. 107
·期 11
·7352-7363
·
IF 3.5
Shengtai Zhang,Zhen Teng,Linzhen Wu,Yongqiang Tan,Chen Chen,Xiaosong Zhou
Designing waste forms using the cocktail effect of high-entropy ceramics can improve the efficiency of ceramic waste forms. In this work, traditional garnet (Y 1.2 Nd 1.8 Fe 5 O 12 , YIG) and high-entropy (HE) garnet (Y 0.6 Gd 0.6 Sm 0.6 Eu 0.6 Dy 0 . 6 Fe 5 O 12 , HEG) are synthesized through ignition and plasma sintering to form dense ceramic waste forms. The chemical stability of YIG and HEG was studied by using static leaching tests at pH = 3, 5, 7, 9, 11. The results indicate that acidic environments can increase the leaching rate of ceramics. Leaching behavior leads to a decrease in lattice volume, but the elements remain uniformly distributed. The leaching mechanism indicates that YIG and HEG are controlled by dissolution and surface effect in the early stage (1–7 days) of leaching. The leaching mechanism in the later stage (14–42 days) is characterized by diffusion control. The diffusion coefficient of long-term leaching indicates that HEG is more suitable as the immobilization substrate for high-level radioactive waste (HLW) than YIG.
研究领域:
材料科学
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核废物管理
✓ 已验证
DOI
高影响因子
JOURNAL OF POROUS MATERIALS
·
2024
·
IF 2.5
Tang Yingying,Xia Yongfeng,Yao Dongxu,Zhu Ming,Zhao Jun,Zeng Yu-Ping
Thermal insulation materials must exhibit superior mechanical properties alongside exceptional thermal insulation conductivity. However, traditional porous ceramics often struggle to meet these dual requirements simultaneously. In high-entropy materials, the phonon scattering induced by lattice distortion effects can significantly reduce the thermal conductivity of ceramics, thus opening new avenues for the design of novel thermal insulation materials. Inspired by the high-entropy effect, this study employed solid-state reaction methods to synthesize (Ce 0.2 Zr 0.2 Ti 0.2 Sn 0.2 Ca 0.2 )O 2−δ (CZTSC) high-entropy ceramics at various temperatures, investigating their phase constituents, microstructural characteristics, and mechanical properties, while exploring the optimal sintering temperature. Additionally, a pore-forming agent method was utilized to fabricate monophasic CZTSC porous ceramics with different porosities at 1400 °C. Specifically, when the pore-forming agent content was 20 wt%, the sample exhibited an apparent porosity of 42.82%, with a low thermal conductivity of 0.57 W·m − 1 ·K − 1 , a low thermal diffusivity of 0.406 mm 2 ·s − 1 , and a relatively high compressive strength of 32.49 MPa. The current investigation underscores the promising prospects of porous CZTSC ceramics in the field of thermal insulation.
研究领域:
材料科学
·
热能工程
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Wenyuan Ma,Yubo Luo,Zheng Ma,Chengjun Li,Yongxin Qian,Wang Li,Tianshun Xiong,Zheng Wang,Xin Li,Qinghui Jiang,Guanchun Wang,Junyou Yang
Herein, five new La 2 Zr 2 O 7 based high-entropy ceramic materials, such as (La 0.2 Ce 0.2 Gd 0.2 Y 0.2 Er 0.2 ) 2 Zr 2 O 7 , (La 0.2 Ce 0.2 Gd 0.2 Er 0.2 Sm 0.2 ) 2 Zr 2 O 7 , (La 0.2 Gd 0.2 Y 0.2 Er 0.2 Sm 0.2 ) 2 Zr 2 O 7 , (La 0.2 Ce 0.2 Y 0.2 Er 0.2 Sm 0.2 ) 2 Zr 2 O 7 , (La 0.2 Ce 0.2 Gd 0.2 Y 0.2 Sm 0.2 ) 2 Zr 2 O 7 ), were synthesized using a sol-gel and high-temperature sintering (1000 °C) method. The spark plasma sintered (SPS) (La 0.2 Ce 0.2 Gd 0.2 Er 0.2 Sm 0.2 ) 2 Zr 2 O 7 pellet shows a low thermal conductivity of 1.33 W m -1 K -1 at 773 K, and it also exhibits better CaO–MgO–Al 2 O 3 –SiO 2 corrosion resistance than that of Y 2 O 3 stabilized ZrO 2 . It shows that (La 0.2 Ce 0.2 Gd 0.2 Er 0.2 Sm 0.2 ) 2 Zr 2 O 7 has a promising application potential as a thermal barrier coating .
研究领域:
材料科学
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能源工程
✓ 已验证
DOI
高影响因子
International Journal of Applied Ceramic Technology
·
2024
·Vol. 21
·期 5
·3422-3434
·
IF 1.8
Zhiyuan Ma,Qingqing Yang,Bin Meng,Xinyu Ping,Xiaoyu Pan,Congcong Fang
A series of (Ba 0.2 Sr 0.2 Na 0.2 Ca 0.2 La 0.2 )(Zr x Ti 1- x )O 3 (BSNCLZ x T 1- x ) ( x = 0, 0.05, 0.1, 0.15, and 0.2) high-entropy ceramics were prepared in forms of bulks and thin films by conventional sintering and spin-coating, respectively. All ceramic bulks and thin films are composed of a single perovskite-structured solid solution. The introduction of the Zr element reduces the dielectric loss of bulks and thin films and improves the frequency stability of the dielectric constant. The ceramic bulks have a higher dielectric constant and lower loss than their corresponding thin films. As x rises from 0 to 0.2, the breakdown strength E b of the ceramic bulks increases from 209 to 327 kV/cm, and that of thin films enhances from 890 to 1770 kV/cm. The bulks and thin films of BSNCLZ 0.1 T 0.9 possess the maximum recoverable energy density W rec (0.82 and 3.48 J/cm 3 ) and energy storage efficiency η (95.8% and 86.8%).
研究领域:
材料科学
·
电子工程
✓ 已验证
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Yiling Huang,Zeyu Chen,Yifei Xiong,jiajie Wu,Chucheng Lin,Wei Zheng,Caifen Jiang,Yi Zeng
Rare earth X2-type monosilicates with low thermal conductivity are crucial for material performance in extreme environments. Three high-entropy ceramics, (Er 1/4 Tm 1/4 Yb 1/4 Lu 1/4 ) 2 SiO 5 , (Y 1/4 Er 1/4 Tm 1/4 Yb 1/4 ) 2 SiO 5 , and (Gd 1/4 Dy 1/4 Er 1/4 Yb 1/4 ) 2 SiO 5 , were synthesized in this study. Among these, the thermal conductivity of (Y 1/4 Er 1/4 Tm 1/4 Yb 1/4 ) 2 SiO 5 at 1200 °C is 1.03 W m −1 K −1 . Concurrently, the stable existence of dislocation arrays was observed in the quaternary high-entropy monosilicate system of (Y 1/4 Er 1/4 Tm 1/4 Yb 1/4 ) 2 SiO 5 . The scattering of medium-frequency phonons can be enhanced by the presence of dislocations, leading to a reduction in thermal conductivity. This provides direct experimental evidence supporting the feasibility of reducing material thermal conductivity through high-entropy design by introducing dislocations.
研究领域:
材料科学
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热物理
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2024
·Vol. 35
·期 11
·1-11
·
IF 2.8
Chen Dongyang,Yang Yujie,Zhang Yingming,Chen Congliang,Li Hao,Meng Yuting,Zhang Zhengyu
Here, a series of high-entropy (Sm 0.2 Eu 0.2 Yb 0.2 Y 0.2 RE 0.2 ) 3 Fe 5 O 12 (RE = La, Nd, Gd, Dy, Er, Tm, Lu) garnet ceramics were synthesized by the solid-phase method. Among them, samples (Sm 0.2 Eu 0.2 Yb 0.2 Y 0.2 RE 0.2 ) 3 Fe 5 O 12 (RE = Nd, Gd, Dy, Er, Tm, Lu) forms single-phase garnet structure, and only sample (Sm 0.2 Eu 0.2 Yb 0.2 Y 0.2 La 0.2 ) 3 Fe 5 O 12 did not form single-phase but some second phases appear. Meanwhile, EDS results show that the approximate equimolar ratio of lanthanides were determined. The effects of different rare-earth composition on the structure and magnetic properties of the high-entropy rare-earth garnet ceramics were systematically investigated. Moreover, the combination of different light and heavy rare-earth makes the magnetism of the high-entropy garnet ceramics interesting, which proves the possibility of controlling the magnetism of high-entropy garnet ceramics.
研究领域:
材料科学
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物理学
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DOI
高影响因子
Small
·
2025
·Vol. 21
·期 8
·2404632
·
IF 12.1
Shuaihang Qiu,Ji Zou,Jingjing Liu,Weimin Wang,Jingjing Xie,Wei Ji,Jinsong Wu,Yanchun Zhou,Zhengyi Fu
Unlike strong yet tough high entropy alloys, high entropy ceramics normally exhibit good hardness but poor strength and fracture toughness. To overcome this obstacle, B 4 C-(Zr 0.2 Hf 0.2 Nb 0.2 Ta 0.2 Ti 0.2 )B 2 composites with a unique hierarchical microstructure are designed and prepared by boronizing reaction sintering of dual-phase multicomponent carbides. In the as-obtained composites, massive platelet-like aggregations assembled by core-rim structured (Zr 0.2 Hf 0.2 Nb 0.2 Ta 0.2 Ti 0.2 )B 2 fine grains are distributed randomly in the B 4 C matrix. Such special microstructure makes B 4 C-(Zr 0.2 Hf 0.2 Nb 0.2 Ta 0.2 Ti 0.2 )B 2 composites exhibit excellent mechanical properties. An extra toughening mechanism of crack bridging is provided in as-obtained composites (fracture toughness of 4.70 ± 0.08 MPa m 1/2 ) by the interaction between cracks and platelet-like diboride aggregations whilst fine-grained microstructures guarantee high flexural strength (633 ± 25 MPa). More importantly, during producing indents, homogenization of core-rim structured (Zr 0.2 Hf 0.2 Nb 0.2 Ta 0.2 Ti 0.2 )B 2 alongside more difficult lattice glides caused by short-range ordering and rough glide planes containing different-dimension transition metal atoms cooperatively induce increased indentation volume work and consequently unparalleled Vickers hardness (>54 GPa at 1.96 N), which is confirmed by in-depth transmission electron microscopy characterizations. This work gives a new inspiration to design high-performance high-entropy ceramics via multi-scale microstructure tailoring and composition tuning.
研究领域:
材料科学
·
固体力学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2024
·
IF 5.8
Yi-fei Tang,Kun-peng Lin,Guo-xiang Zhou,Zhi-hua Yang,Feng-nian Zhang,Zhe Zhao,Yan-zhao Zhang,De-chang Jia,Yu Zhou
High entropy ceramics are considered as promising materials for thermal barrier coatings due to phonon scattering caused by lattice distortion. In this study, perovskite high-entropy ceramics (Ba 0.5 Sr 0.5 )(Ti 0.25 Zr 0.25 Hf 0.25 Sn 0.25 )O 3 (BSTZHS) were successfully prepared by dramatically increasing the conformational entropy of ceramics with complex crystal structures. The results showed that the sample exhibits a single-phase perovskite crystal structure with a dense surface, each element of the sample was uniformly distributed. Moreover, the thermal conductivity of (Ba 0.5 Sr 0.5 )(Ti 0.25 Zr 0.25 Hf 0.25 Sn 0.25 )O 3 decreased significantly compared to SrZrO 3 and BaZrO 3 (the minimum thermal conductivity is 1.37 W/(m·K) at 273–1273 K). This study also identified descriptors for predicting the decrease in thermal conductivity of perovskite high-entropy ceramics. As well, the samples not only exhibit outstanding mechanical properties (Young’s modulus E = 255.7 ± 8.6 GPa、flexural strength F b = 142.1 ± 4.8 MPa), but also good resistance to CMAS corrosion. Various results support that (Ba 0.5 Sr 0.5 )(Ti 0.25 Zr 0.25 Hf 0.25 Sn 0.25 )O 3 is potential to be used for thermal barrier coatings.
研究领域:
材料科学
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热力学工程
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2022
·Vol. 15
·期 22
·8079
·
IF 3.748
Zhanqiang Li,Junfeng Zheng,Wenjuan Zhang,Yong Zheng,Weijun Zhao,Liyan Xue,Fan Yang,Heng Chen
YSZ has been widely used as a TBC material, but its phase change at high temperatures limits its development, thus the need for developing new thermal barrier materials resistant to high temperatures. Rare-earth aluminate ceramics with a garnet structure (Yb3Al5O12) have been considered as a potential thermal barrier material. The melting point of Yb3Al5O12is 2000 °C, which has a potential high temperature application prospect. However, Yb3Al5O12has lower thermal expansion and higher thermal conductivity than YSZ, which is a widely employed thermal barrier coating (TBC) material. To overcome these obstacles, (Y0.2Dy0.2Ho0.2Er0.2Yb0.2)3Al5O12, a high-entropy ceramic, was prepared by a solid-state reaction and pressureless sintering. The thermal conductivity of the (Y0.2Dy0.2Ho0.2Er0.2Yb0.2)3Al5O12was 3.48 W/(m·K) at 300 K, approximately 25.48% lower than that of the Yb3Al5O12 (4.67 W/(m·K)). The thermal expansion coefficient of the (Y0.2Dy0.2Ho0.2Er0.2Yb0.2)3Al5O12was 9.28 × 10−6K−1at 673-1273 K, approximately 18.52% higher than that of the Yb3Al5O12(7.83 × 10−6K−1, 673-1273 K). When the (Y0.2Dy0.2Ho0.2Er0.2Yb0.2)3Al5O12was annealed at 1550 °C for 7 days, its average grain size only increased from 0.7 μm to 1.3 μm. Moreover, the (Y0.2Dy0.2Ho0.2Er0.2Yb0.2)3Al5O12exhibited better chemical stability and a lower grain growth rate than the Yb3Al5O12. This study reveals that (Y0.2Dy0.2Ho0.2Er0.2Yb0.2)3Al5O12is a promising candidate for the future generation of thermal barrier materials.Keywords:rare-earth aluminates;high-entropy ceramics;thermal barrier material;chemical stability
研究领域:
材料科学
·
高温材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Sehreish Abrar,Zhuang Ma,Ling Liu,Faisal Nazeer,Abdul Malik
The materials which have low thermal conductivity , a good match of coefficient of thermal expansion with SiC-based ceramics matrix composites (CMCs) and excellent resistance against calcium-magnesium-alumina-silicate (CMAS) are suitable candidates for thermal/environmental barrier coating. To fulfil the above requirements we developed a new multicomponent rare earth (Y 0.2 Dy 0.2 Er 0.2 Yb 0.2 Ho 0.2 ) 2 Si 2 O 7 or (5RE 0.2 ) 2 Si 2 O 7 high entropy ceramics pyrosilicate by a single step solid solution method. The x-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analysis revealed that the as-fabricated bulk composite (5RE 0.2 ) 2 Si 2 O 7 has a single phase β-type structure match well with single rare earth ytterbium disilicate (Yb 2 Si 2 O 7 ) and the different rare earth oxides mixed well with each other. The excellent coefficient of thermal expansion (4 × 10 −6 -5 × 10 −6 °C −1 ) and ultra-low thermal conductivity (0.7–1.6 W/m C) was observed as compared to other single and multicomponent high entropy ceramics composites. The (5RE 0.2 ) 2 Si 2 O 7 ceramics pyrosilicate show an excellent CMAS resistance at various temperatures (1300, 1400, and 1500) °C for 4 h compared with single principle RE disilicates. The above all mentioned results identify that this material is a suitable candidate for coating on the SiC-based ceramics composite for thermal/environmental barrier coating.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2023
·
IF 10.9
Jingxin Wu,Meng Zhang,Zhanqiang Li,Minzhong Huang,Huiming Xiang,Liyan Xue,Zhengming Jiang,Zhigang Zhao,Lianfeng Wei,Yong Zheng,Fan Yang,Guang Ran,Yanchun Zhou,Heng Chen
Nuclear engineering materials are required to possess outstanding extreme environmental tolerance and irradiation resistance. A promising novel pyrochlore-type of (Sm 0.2 Eu 0.2 Gd 0.2 Dy 0.2 Er 0.2 ) 2 Hf 2 O 7 high-entropy ceramic (HE-RE 2 Hf 2 O 7 ) for control rod was prepared by solid-state reaction method. The ion irradiation of HE-RE 2 Hf 2 O 7 with 400 keV Kr + at 400 °C was investigated using a 400 kV ion implanter and compared with single-component pyrochlore Gd 2 Hf 2 O 7 to evaluate the irradiation resistance. For HE-RE 2 Hf 2 O 7 , the phase transition from pyrochlore to defective fluorite is revealed after irradiation at 60 dpa. After irradiation at 120 dpa, it maintained crystalline, which is comparable to Gd 2 Hf 2 O 7 but superior to the titanate pyrochlores previously studied. Moreover, the lattice expansion of HE-RE 2 Hf 2 O 7 (0.22%) is much lower than that of Gd 2 Hf 2 O 7 (0.62%), indicating excellent irradiation damage resistance. Nanoindentation tests displayed an irradiation-induced increase in hardness and a decrease in elastic modulus by about 2.6%. Irradiation-induced segregation of elements is observed on the surface of irradiated samples. In addition, HE-RE 2 Hf 2 O 7 demonstrates a more sluggish grain growth rate than Gd 2 Hf 2 O 7 at 1200 °C, suggesting better high-temperature stability. The linear thermal expansion coefficient of HE-RE 2 Hf 2 O 7 is 10.7 × 10 -6 K -1 at 298–1273 K. In general, it provides a new strategy for the design of the next advanced nuclear engineering materials.
研究领域:
核工程材料
·
材料科学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）