硅酸盐学报

Y2O3掺杂对La2Zr2O7陶瓷结构与热物理性能的影响

作者：谢敏1 2 张永和2 周芬2 宋希文2 安胜利1 2

单位：1. 北京科技大学冶金与生态学院北京 100083 2. 内蒙古科技大学材料与冶金学院内蒙古包头 014010

分类号：TG174.45；TQ174

出版年,卷(期):页码：2016,44(9):1352-1356

DOI：10.14062/j.issn.0454-5648.2016.09.16

摘要：

用Y2O3掺杂La2Zr2O7制备(La1–xYx)2Zr2O7(x=0，0.1，0.2，x为摩尔分数)陶瓷材料，利用X射线衍射仪、扫描电子显微镜、激光导热仪以及热膨胀仪分别对其物相结构、显微形貌、热导率及热膨胀性能进行表征。结果表明，(La1–xYx)2Zr2O7为立方烧绿石结构，显微结构致密，在室温至1 450 ℃范围内具有良好的高温相稳定性。La2Zr2O7掺杂小离子半径Y3+可提高其热膨胀系数(x=0.2)，降低热扩散系数，并在高温下表现出类似于玻璃的超低热导率。1 000 ℃时，La1.6Y0.4Zr2O7的热导率为1.28 W/(m·K)，平均热膨胀系数达到9.7×10–6/K。

(La1–xYx)2Zr2O7 (x=0, 0.1, 0.2) ceramics were synthesized by Y2O3 doping in La2Zr2O7. The phase structure was analysed by X-ray diffractometer. The feature surface was determined by scanning electron microscope. The thermal diffusivities and thermal expansion coefficient (TEC) of the ceramic materials were examined by a laser-flash method and thermal dilatometer, respectively. The results show that (La1–xYx)2Zr2O7 exhibits a pyrochlore crystal structure, a dense microstucture and a superior structural stability at a high temperature. The ceramic doped with smaller Y3+ shows a higher thermal expansion coefficent(TEC) (x=0.2), lower thermal diffusivities and a nearly temperature-independent behavior reported as glass-like extraordinarily low thermal conductivities. The thermal conductivity of La1.6Y0.4Zr2O7 is 1.28 W/(m·K) at 1 000 ℃, and the average TEC is 9.7×10–6/K.

基金项目：

国家高技术研究发展计划(2015AA034403)；内蒙古自治区科技创新引导奖励资金计划(20140508-2)；内蒙古科技大学材料与冶金学院青年人才孵化器平台(2014CY012)资助。

作者简介：

谢敏(1981—)，女，博士研究生。

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