High-entropy(La_(0.2)Nd_(0.2)Sm_(0.2)Eu_(0.2)Gd_(0.2))_(2)Ce_(2)O_(7):A potential thermal barrier material with improved thermo-physical properties

作     者：Yun XUE Xiaoqin ZHAO Yulong AN Yijing WANG Meizhen GAO Huidi ZHOU Jianmin CHEN Yun XUE;Xiaoqin ZHAO;Yulong AN;Yijing WANG;Meizhen GAO;Huidi ZHOU;Jianmin CHEN

作者机构：Key Laboratory of Science and Technology on Wear and Protection of MaterialsLanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China Center of Materials Science and Optoelectronics EngineeringUniversity of Chinese Academy of SciencesBeijing 100049China Key Lab for Magnetism and Magnetic Materials of MOESchool of Physical Science and TechnologyLanzhou UniversityLanzhou 730000China 

出 版 物：《Journal of Advanced Ceramics》 (先进陶瓷（英文）)

年 卷 期：2022年第11卷第4期

页      面：615-628页

核心收录：

学科分类：08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：This research was financially supported by Youth Innovation Promotion Association(No.2014378)for Chinese Academy of Sciences.The authors are grateful to the constructive comments of the reviewers. 

主　　题：high-entropy oxides(HEOs) (La_(0.2)Nd_(0.2)Sm_(0.2)Eu_(0.2)Gd_(0.2))_(2)Ce_(2)O_(7) defective fluorite structure thermal expansion coefficient(TEC) thermal conductivity thermal barrier coating(TBC) 

摘      要：High-entropy oxides(HEOs)are widely researched as potential materials for thermal barrier coatings(TBCs).However,the relatively low thermal expansion coefficient(TEC)of those materials severely restricts their practical application.In order to improve the poor thermal expansion property and further reduce the thermal conductivity,high-entropy(La_(0.2)Nd_(0.2)Sm_(0.2)Eu_(0.2)Gd_(0.2))_(2)Ce_(2)O_(7) is designed and synthesized in this work.The as-prepared multicomponent material is formed in a simple disordered fluorite structure due to the high-entropy stabilization effect.Notably,it exhibits a much higher TEC of approximately 12.0×10^(−6) K^(−1) compared with those of other high-entropy oxides reported in the field of TBCs.Besides,it presents prominent thermal insulation behavior with a low intrinsic thermal conductivity of 0.92 W·m^(−1)·K^(−1) at 1400℃,which can be explained by the existence of high concentration oxygen vacancies and highly disordered arrangement of multicomponent cations in the unique high-entropy configuration.Through high-temperature in-situ X-ray diffraction(XRD)measurement,this material shows excellent phase stability up to 1400℃.Benefiting from the solid solution strengthening effect,it shows a higher hardness of 8.72 GPa than the corresponding single component compounds.The superior thermo-physical performance above enables(La_(0.2)Nd_(0.2)Sm_(0.2)Eu_(0.2)Gd_(0.2))_(2)Ce_(2)O_(7) a promising TBC material.