Na0.54Bi0.46Ti0.96Al0.04O2.94氧离子导体制备与性能研究

采用传统的固相反应法合成Na0.54Bi0.46Ti0.96Al0.04O2.94氧离子导体,借助于交流阻抗谱和介电弛豫谱分别研究了钠和铝的双掺杂对Na0.5Bi0.5TiO3材料电学性能及氧离子扩散的影响。在400℃时,Na0.54Bi0.46Ti0.96Al0.04O2.94材料的晶粒电导率可以达到1.51×10-3 S/cm,是Na0.5Bi0.5TiO3材料电导率的5.5倍。在Na0.54Bi0.46Ti0.96Al0.04O2.94材料中观察到一个与氧离子弛豫相关的介电弛豫峰,弛豫参数为E= 0.80 eV和t0= 6.12×10-13 s,氧离子在Na0.54Bi0.46Ti0.96Al0.04O2.94材料中主要通过Na-Bi-Ti的路径进行扩散迁移的。结合结构参数容忍因子及自由体积的分析,钠和铝的双掺杂改善了氧离子在Na0.5Bi0.5TiO3材料中的扩散通道,但是铝的引入一定程度上提高了氧空位扩散的能量壁垒。

The investigation on the preparation and performance of oxide ion conductor Na0.54Bi0.46Ti0.96Al0.04O2.94

Na0.54Bi0.46Ti0.96Al0.04O2.94 samples were prepared by conventional solid-state reaction. AC impedance and dieletric relaxation spectroscopy were employed to study the electrical performance and oxgyen ion diffusion in the Na0.5Bi0.5TiO3 doped by the Na+ and Al3+. The bulk conductivity of Na0.54Bi0.46Ti0.96Al0.04O2.94 sample can arrive at 1.51×10-3 S/cm at 673 K in air atmosphere, higher 5.5 times than that of the Na0.5Bi0.5TiO3 compound at the same temperature. An apparent dielectric relaxation peak was observed. The relaxation parameters can be obtained, E= 0.80 eV and t0= 6.12×10-13 s. The relaxation peak may be caused by the oxide ion diffusion by the Na-Bi-Ti pathways in the Na0.54Bi0.46Ti0.96Al0.04O2.94 sample. Combined with the analysis of the tolerance factor and specific free volume, the dopant of Na+ and Al3+ ions doping in the Na0.5Bi0.5TiO3 compound is favorable to the oxygen ion diffusion in Na0.5Bi0.5TiO3 compound. However,Al3+ ions dopant increases the energy barrier height of oxygen ion diffusion.