Elevating the comprehensive thermal properties of rare-earth cerates through high-entropy design  

作　　者：Zhaoxuan Zhang Yiling Huang Fan Peng Wei Zheng Caifen Jiang Xuemei Song Yi Zeng 

机构地区：[1]School of Microelectronics,Shanghai University,Shanghai,201800,China [2]The State Key Lab of High Performance Ceramics and Superfine Microstructure,Shanghai Institute of Ceramics,Chinese Academy of Science,Shanghai,200050,China

出　　处：《Journal of Materiomics》2024年第5期1126-1136,共11页无机材料学学报（英文）

基　　金：This work was supported by the Instrument and equipment development,Chinese Academy of Sciences[YJKYYQ20210030];Shanghai Science and Technology Innovation Action Plan[21142201100].

摘　　要：In the rapidly evolving aerospace sector,the quest for sophisticated thermal barrier coating(TBC)materials has intensified.These materials are primarily sought for their superior comprehensive thermal characteristics,which include a low thermal conductivity coupled with a high coefficient of thermal expansion(CTE)that synergizes with the substrate.In our study,we adopt a solid-state method to synthesize a series of high-entropy rare-earth cerates:La_(2)Ce_(2)O_(7)(1RC),(La_(1/2)Nd_(1/2))2Ce_(2)O_(7)(2RC),(La_(1/3)Nd_(1/3)Sm_(1/3))_(2)Ce_(2)O_(7)(3RC),(La_(1/4)Nd_(1/4)Sm_(1/4)Eu_(1/4))_(2)Ce_(2)O_(7)(4RC),and(La_(1/5)Nd_(1/5)Sm_(1/5)Eu_(1/5)Gd_(1/5))_(2)Ce_(2)O_(7)(5RC),all sintered at 1,600℃ for 10 h.We thoroughly examine their phase structure,morphology,elemental distribution,and thermal properties.Our in-depth analysis of the phonon scattering mechanisms reveals that 4RC and 5RC exhibit exceptional thermal properties:high CTEs of 13.00×10^(−6) K^(−1) and 12.77×10^(−6) K^(−1) at 1,400℃,and low thermal conductivities of 1.55 W/(m·K)and 1.68 W/(m·K)at 1,000℃,respectively.Compared to other TBC systems,4RC and 5RC stand out for their excellent thermal characteristics.This study significantly contributes to the development of high-entropy oxides for TBC applications.

关 键 词：Thermal barrier coatings(TBCs) Comprehensive thermal properties Coefficient of thermal expansion Thermal conductivity Phonon scattering mechanisms 

分 类 号：TQ174.1[化学工程—陶瓷工业] TG139[化学工程—硅酸盐工业]