中文摘要：

采用X射线衍射、高分辨透射电镜、选区电子衍射、拉曼光谱以及阻抗谱等手段研究了稀土锆酸盐（A_2Zr_2O_7）材料的晶体结构和电学性能,发现稀土锆酸盐A_2Zr_2O_7的有序度随稀土阳离子半径的减小逐渐降低。Sm_2Zr_2O_7和Eu_2Zr_2O_7陶瓷为有序的烧绿石相,而Gd_2Zr_2O_7和Dy_2Zr_2O_7为无序的缺陷型萤石相。与其它几种稀土锆酸盐的电导率相比,有序度相对较低的烧绿石相Eu_2Zr_2O_7具有最大的晶粒电导率（1.03×10~（-2）S·cm~（-1）,1173 K）。

英文摘要：

The micro structure and electrical conductivity of A_2Zx_2O_7 ceramic have been investigated by X-ray diffraction（XRD）,high resolution transmission electron microscopy（HRTEM） coupled with selected area electron diffraction（SAED）,Raman spectroscopy and Impedance spectroscopy.The results show that the degree of structural order of rare-earth zirconates A_2Zr_2O_7 ceramics gradually decreases with reducing ionic radius of rare-earth cations.The Sm_2Zr_2O_7 and Eu_2Zr_2O_7 ceramics exhibit an ordered pyrochlore phase,while Gd_2Zr_2O_7 and Dy_2Zr_2O_7 ceramics have a disordered fluorite phase.Pyrochlore-type Eu_2Zr_2O_7 ceramic with a relatively low structural order degree shows the maximum grain conductivity of 1.03×10~（-2） S·cm~（-1） at 1173 K,as compared with that of other rare-earth zirconates.