Journal of Inorganic Materials ›› 2021, Vol. 36 ›› Issue (4): 411-417.DOI: 10.15541/jim20200426

Special Issue: 【结构材料】热障与环境障涂层 【结构材料】高熵陶瓷

• RESEARCH PAPER • Previous Articles     Next Articles

Preparation and Thermal Properties of Rare Earth Tantalates (RETaO4) High-Entropy Ceramics

ZHU Jiatong, LOU Zhihao, ZHANG Ping, ZHAO Jia, MENG Xuanyu, XU Jie(), GAO Feng   

  1. State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072, China
  • Received:2020-08-05 Revised:2020-09-14 Published:2021-04-20 Online:2020-10-30
  • Contact: XU Jie, associate professor. E-mail:
  • About author:ZHU Jiatong(1997-), male, Master candidate. E-mail:
  • Supported by:
    Natural Science Foundation of China(51702259);Natural Science Foundation of China(52072301);Natural Science Basic Research Program of Shaanxi Province(2019JM-432)


Single-phase solid solution monoclinic structure high-entropy tantalates (Nd1/6Sm1/6Eu1/6Gd1/6Dy1/6Ho1/6) TaO4(6RETaO4), (Nd1/5Sm1/5Eu1/5Gd1/5Dy1/5)TaO4(5RETaO4), (Nd1/4Sm1/4Eu1/4Gd1/4)TaO4(4RETaO4) were prepared by solid state method. STEM-EDS result shows the rare earth elements are uniformly distributed without segregation. The ferroelastic domain observed through SEM derived from the second ferroelastic phase transition. The thermal expansion experiment suggests the good thermal stability below 1200 ℃, where the thermal expansion coefficient of 6RETaO4 reaches 9.25×10-6K-1 at 1200 ℃. Due to the increase of phonon scattering derived from high-entropy effect, RETaO4 ceramics exhibit lower intrinsic thermal conductivity (2.98-1.23 W·m-1·K-1, 100-1000 ℃) and enhanced mechanical properties (6RETaO4, (9.97±2.2) GPa), which indicates that it is a potential material for thermal barrier coatings.

Key words: thermal barrier coating, rare earth tantalate, high-entropy ceramics, thermal property

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