摘要
探讨了采用固相反应法合成碱土金属 Sr、Mg 与过渡金属 Fe 复合掺杂的镓酸镧基 ABO_3型氧化物 La_(0.8)Sr_(0.2)Ga_(0.75)Mg_(0.20)Fe_(0.05)O_(2.815)(LSGMF);利用热分析仪、EDS、XRD、SEM、直流四端子法等对 LSGMF 复合氧化物的形成过程、微区成分、晶体结构、显微组织及导电性等进行研究。分析表明:样品的烧结温度不能低于1300℃;EDS 结果证实合成的 LSGMF 样品中杂质元素很少,纯度较高;XRD 分析表明:经1350℃烧结合成的 LSGMF 样品中出现了 LaSrGa_3O_7和 LaSrGaO_4等杂相,而经1400℃烧结则获得了单一正交钙钛矿结构;电性能测试结果表明:在400-850℃温度区间,其电导率与温度的关系符合 Arrhenius 定律,说明合成的复合氧化物LSGMF 为氧离子导体,且离子迁移活化能0.6656eV(<leV);Sr、Mg 和 Fe 复合掺杂氧化物 LSGMF 与仅 Sr、Mg 双掺杂氧化物LSGM 相比具有更高的离子电导率,说明少量过渡金属 Fe 的掺杂,可提高离子电导率。
Compositely Doped Oxide La0.8sSr0.2Ga0.75Mg0.20Fe0.05O2.815（LSGMF201703） was synthesized by solid state reaction method. The composition, structure, morphology and ionic conductivity of the samples were analyzed by EDS, XRD, SEM and four-probe DC measurements. The result shows that LSGMF201703 sintered at 1400℃ possesses orthorhombic perovskite-type structure, and impurity phases have not been found in them. However, there exist impurity phases such as LaSrGa3O7 and LaSrGaO4 in the samples sintered at 1350℃. Electrical measurement results show LSGMF201703 are oxygen ion conductors based on the fact that temperature dependence of the conductivity conforms to the Arrhenius equation at 400℃-850℃, and the value of activation energy is 0.6656eV （〈leV=. The ionic conductivity of LSGMF201703 is higher than that of LSGM2025 in testing temperature range. Thus, proper amount of Sr and Mg doping is beneficial to high ionic conductivity.
出处
《陶瓷学报》
CAS
2007年第1期6-11,共6页
Journal of Ceramics
基金
天津市自然科学基金(编号:33700111)
关键词
钙钛矿结构
离子导体
镓酸镧
离子电导率
perovskite structure, oxygen ion conductor, lanthanum gallate, ionic conductivity
