Abstract Ferroelastic ABO4 type RETaO4 and RENbO4 ceramics (where RE stands for rare earth) are being investigated as promising thermal barrier coatings (TBCs), and the mechanical properties of RETaO4 have been found to be better than those of RENbO4. In this work, B-site substitution of tantalum (Ta) is used to optimize the thermal and mechanical properties of EuNbO4 fabricated through a solid-state reaction (SSR). The crystal structure is clarified by means of X-ray diffraction (XRD) and Raman spectroscopy; and the surface microstructure is surveyed via scanning electronic microscope (SEM). The Young’s modulus and the thermal expansion coefficient (TEC) of EuNbO4 are effectively increased; with respective maximum values of 169 GPa and 11.2 × 10−6 K−1 (at 1200 °C). The thermal conductivity is reduced to 1.52 W·K−1·m−1 (at 700 °C), and the thermal radiation resistance is improved. The relationship between the phonon thermal diffusivity and temperature was established in order to determine the intrinsic phonon thermal conductivity by eliminating the thermal radiation effects. The results indicate that the thermal and mechanical properties of EuNbO4 can be effectually optimized via the B-site substitution of Ta, and that this proposed material can be applied as a high-temperature structural ceramic in future.

中文翻译：

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Ta的B位取代优化ABO4型EuNbO4的热力学性能

摘要 铁弹性 ABO4 型 RETaO4 和 RENbO4 陶瓷（其中 RE 代表稀土）正在研究作为有前途的热障涂层 (TBC)，并且已发现 RETaO4 的机械性能优于 RENbO4。在这项工作中，钽 (Ta) 的 B 位取代用于优化通过固态反应 (SSR) 制造的 EuNbO4 的热性能和机械性能。晶体结构通过X射线衍射（XRD）和拉曼光谱阐明；并通过扫描电子显微镜（SEM）观察表面微观结构。EuNbO4的杨氏模量和热膨胀系数（TEC）有效提高；最大值分别为 169 GPa 和 11.2 × 10−6 K−1（在 1200 °C）。热导率降低到 1.52 W·K−1·m−1（700 °C 时），并且提高了抗热辐射性。建立声子热扩散率和温度之间的关系是为了通过消除热辐射效应来确定本征声子热导率。结果表明，EuNbO4 的热性能和机械性能可以通过 Ta 的 B 位取代有效地优化，并且这种材料可以在未来用作高温结构陶瓷。