ABSTRACT Pyrochlore Gd2(Zr1−xNbx)2O7+x (x = 0, 0.05, 0.1, 0.15) ceramic materials were synthesised using a high-temperature solid-state reaction method. The phase structure, thermal expansion coefficient and thermal conductivity of Gd2(Zr1−xNbx)2O7+x were investigated in this work. The results show that with the introduction of Nb2O5, Gd2(Zr1−xNbx)2O7+x ceramic materials present a cubic pyrochlore structure. Meanwhile, Gd2(Zr1−xNbx)2O7+x ceramics have clear grain boundaries. The thermal expansion coefficient of Gd2(Zr1−xNbx)2O7+x ceramic materials reduces from 11.4576 × 10−6 to 10.7919 × 10−6 K−1 (larger than 10 × 10−6 K−1), while its thermal conductivity gradually increases with the doping of Nb5+ ions. Considering their comprehensive properties, Gd2(Zr1−xNbx)2O7+x compounds may be considered as promising thermal barrier coatings materials.

中文翻译：

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Nb5+掺杂对Gd2(Zr1−xNbx)2O7+x陶瓷热性能的影响

摘要 烧绿石 Gd2(Zr1−xNbx)2O7+x (x = 0, 0.05, 0.1, 0.15) 陶瓷材料是使用高温固相反应方法合成的。本文研究了 Gd2(Zr1−xNbx)2O7+x 的相结构、热膨胀系数和热导率。结果表明，随着Nb2O5的引入，Gd2(Zr1−xNbx)2O7+x陶瓷材料呈现立方烧绿石结构。同时，Gd2(Zr1−xNbx)2O7+x 陶瓷具有清晰的晶界。Gd2(Zr1−xNbx)2O7+x 陶瓷材料的热膨胀系数从 11.4576 × 10−6 降低到 10.7919 × 10−6 K−1（大于 10 × 10−6 K−1），而其热导率逐渐降低随着 Nb5+ 离子的掺杂而增加。考虑到它们的综合性能，Gd2(Zr1−xNbx)2O7+x 化合物可以被认为是有前途的热障涂层材料。