新型固体电解质La_2Mo_2O_9的制备及其性能  

Preparation and Properties of New Solid Electrolyte La_2Mo_2O_9

作　　者：黄应龙[1] 贺天民[1] 纪媛[1] 王金霞[1] 王德涌[1] 

机构地区：[1]吉林大学物理学院,吉林长春130023

出　　处：《中国稀土学报》2004年第1期113-118,共6页Journal of the Chinese Society of Rare Earths

基　　金：吉林省科技厅(20000322)资助项目

摘　　要：用固相法制备了新型固体电解质La2Mo2O9,用热膨胀仪、X射线衍射仪和Raman光谱分析了La2Mo2O9相的形成过程。用交流阻抗谱和热膨胀仪对合成样品的电学和热学性能进行了研究,分析了热处理温度对La2Mo2O9相的形成过程和电学性能的影响,确定了样品获得高电学性能的最佳条件。研究结果表明:600℃时样品中开始形成La2Mo2O9相,700℃以上烧结的样品可获得具有完整氧空位的La2Mo2O9相。900℃烧结10h可获得具有高密度和高电导率的La2Mo2O9氧离子导体。样品的电学性能随烧结温度的升高而增大,900℃时烧结的样品在800℃时的电导率为0.067S·cm-1,远高于同温度下YSZ的电导率,与晶粒电阻相比,晶界电阻非常小。用热膨胀仪测得La2Mo2O9在555℃时有一个一级相变,对应α La2Mo2O9到β La2Mo2O9的相变。A new solid electrolyte La_2Mo_2O_9 was prepared by solid-state reaction method. The forming process of La_2Mo_2O_9 phase was analyzed using thermal dilatometer, X-ray diffractometer and Raman spectra. The electrical and thermal properties of the synthesized samples were studied using a.c. impedance spectra and thermal dilatometer. The effects of thermal treatment temperature on the forming process of La_2Mo_2O_9 phase and the electrical properties of sample were analyzed, and the optimal condition that high conductivity of the samples can be determined was observed. The results show that La_2Mo_2O_9 phase in samples is formed at thermal treatment temperature of 600 ℃. The La_2Mo_2O_9 phase with oxygen vacancy is formed completely above sintering temperature of 700 ℃. The electrical properties of sample increase with increasing of the sintering temperatures. The conductivity of La_2Mo_2O_9 sample sintered at 900 ℃ for 10 h is 0.067 S·cm^(-1) at 800 ℃, which is higher than that of YSZ sample at the same measuring temperature. Compared to grain resistances, the grain boundary resistances of La_2Mo_2O_9 are much smaller. A first-order phase transition of La_2Mo_2O_9 was detected at 555 ℃ using thermal dilatometer, corresponding a structural transition from α-La_2Mo_2O_9 to β-La_2Mo_2O_9.

关 键 词：能源材料 La2Mo2O9 固相反应 固体电解质 电导率 相变 稀土 

分 类 号：TQ136.12[化学工程—无机化工] TQ133.3