稀土Y2O3和Gd2O3共掺杂对La2(Zr0.7Ce0.3)2O7陶瓷相结构及热膨胀系数的影响

Structure and thermal expansion behavior of La2(Zr0. 7Ce0. 3)2O7 with A-site partially substituted with equimolar Y2O3 and Gd2O3

采用固相合成法制备了（La1-2xYxGdx）2（Zr0.7Ce0.3）2O7（x=0,0.30,0.35,0.40,0.45,0.50）体系陶瓷材料.分别利用XRD、扫描电子显微镜和高温热膨胀仪对陶瓷材料的相组成、微观形貌及热膨胀系数进行测试.结果表明.掺杂量x=0时为立方烧绿石结构,x≥0.30时为立方萤1石结构;晶粒发育良好,晶界清晰;Y2O3和Gd2O3的掺杂可以有效的提高La2（Zr0.7Ce0.3）2O7的热膨胀系数.

The （ La1-2xYxGdx ） 2 （ Zr0.7Ce0.3）2O7 （ x = 0, 0.30, 0.35,0.40, 0.45, 0.50） ceramics were synthesized hy a golid state reaction method. The phase structure, mierostructure and thermal expansion coefficient of the ceramics were characterized by X-ray diffraction, scanning electron microscopy and high-temperature dilatometer, respectively. The XRD results of the ceramics sintered at 1 600℃ for 5 h indicate that the Laz （Zr0.7 Ce0.3 ）207 ceramic is composed of the pure pyrochlore structure and the （La1-2xYxGdx）2 （Zr0.7 Ce0.3 ）2O7 （X≥0. 30） ceramics are composed of the pure fluorite structure. The SEM results of the ceramics sintered at 1600℃ for 5 h indicate that the grains grew up uniformly, and the grain boundaries were clean. The substitution of Y2O3 and Gd2O3 resulted in an increase in the thermal expansion coefficients.