Er^(3+)掺杂对Nd_2Zr_2O_7相结构及热物理性能的影响

Effects of Er^(3+) Doping on Phase Structure and Thermal Physical Properties of Nd_2Zr_2O_7

利用固相合成法得到Nd_(2-x)Er_xZr_2O_7(0≤x≤1.0)陶瓷材料,分别利用X射线衍射仪、扫描电子显微镜、激光导热仪对材料的晶体结构、显微形貌及热扩散系数进行表征,并对其热导率进行分析。结果表明,Nd_(2-x)Er_xZr_2O_7晶体表现为立方相,获得稳定烧绿石结构Nd_(2-x)Er_xZr_2O_7陶瓷材料的x值应控制在0.8以内;Er^(3+)对A位较大的Nd^(3+)进行取代并固溶到了晶格中,使晶格参数减小;陶瓷的晶粒尺寸减小至1μm^3μm,Er^(3+)具有抑制烧结的作用;室温至1000℃范围内,Er^(3+)对Nd^(3+)的取代掺杂可以有效降低陶瓷材料的热导率,1000℃时Nd_(1.4)Er_(0.6)Zr_2O_7热导率为1.76 W·m^(-1)·K^(-1)。

Nd2-xErxZr2O7（0≤x≤1.0） ceramics were synthesized by solid phase synthesis method. The phase structure was analysed by XRD, the feature surface was observed by SEM, and the thermal diffusivities of ceramic materials were tested by laser- flash method respectively. The results show that Nd2-x ErxZr2O7 exhibited cubic structures and the value of x should be less than 0.8 for stable pyrochlore. Er3 ＋ substituted bigger Nd3 ＋ located A - site in the lattice and dissolved in solid solu- tion. With the growing of x , the grain size of ceramic decreased to 1 - 3 μm which indicated Er3＋ have a inhibitory effect on ceramic sintering. From RT to 1000 ℃, the Er3＋ subsitute of Nd3＋ decreased the thermal conductivities of the ceramics and reached to 1.7 6w · m-1· K-1 at 1000℃.