新型氧离子导体La1.84R0.16Mo1.7W0.3O8.92(R=Ca^2＋、Sr^2＋、Ba^2＋)的制备及其电性能

Synthesis and electrical properties of a new ion-conductor of La_(1.84)R_(0.16)Mo_(1.7)W_(0.3)O_(8.92)(R=Ca^(2+)、Sr^(2+)、Ba^(2+))

以La2Mo1.7W0.3O9为本体,在La位进行碱土金属掺杂,采用溶胶-凝胶方法合成新型氧离子导体La1.84R0.16Mo1.7W0.3O8.92(R=Ca2+、Sr2+、Ba2+)。应用示差热分析(DTA)、X射线衍射(XRD)、拉曼光谱(Raman)等手段对氧化物进行结构表征,交流阻抗谱测试电性能。结果表明:掺杂改善了本体导电性能的同时,保持了La2Mo1.7W0.3O9抑制La2Mo2O9相变的功能;碱土离子的掺杂,在体系中引入了氧空位,有利于氧离子扩散,提高氧离子导电性,773K时Ba2+掺杂体系的电导率为1.0×10-4S/cm,高于本体的电导率(5.0×10-5S/cm)。

Based on the compound La2Mo1.7W0.3O9, new oxygen ion-conductor La1.84R0.16Mo1.7W0.3O8.92（R=Ca^2＋、Sr^2＋、Ba^2＋） was prepared by sol-gel method. The structure and conductivity of samples were characterized by powder X-ray diffraction （XRD）, differential thermal analysis （TG/DTA）, Raman and Impedance spectroscopy. La1.84R0.16Mo1.7W0.3O8.92 shows the β phase at room temperature and better conductivity than La2Mo1.7W0.3O9. Additional oxygen vacancies are introduced into La2Mo1.7W0.3O9 lattice by substitution, and then the oxygen ionic conductivity increased. At 773K, the conductivity of La1.84Ba0.16Mo1.7W0.3O8.92 is 1.09 × 10^-4 S/cm, higher than the conductivity of La2Mo1.7W0.3O9 5 × 10^- 5 S/cm.