中文摘要：

采用改进的固相反应法合成了锶、镁与铁或钴多元掺杂的LaGa03基稀土复合氧化物La0．8Sr0．2Ga0．72Mg0．20Fe0．08O2．8（LSGMF）和La0．8Sr0．2Ga0．72Mg0．20Co0．08O2．8（LSGMC），利用EDS、XRD及SEM等方法对LSGMF和LSGMC的化学成分、物相组成及显微组织等进行了分析；采用直流四端子法测量了两者在350～850℃温度区间的电导率。结果表明：经1400℃烧结后，LSGMF和LSGMC均形成单一正交钙钛矿结构；两者除含少量钙外，不合其他杂质元素；在测试温度范围，材料的电导率与温度的关系分区间符合Arrhenius方程，在较低温阶段（350～500℃）具有较低的导电活化能（E〈0．3eV）；与仅用锶、镁双掺杂的LSGM相比，LSGMF和LSGMC具有较高的电导率。

英文摘要：

LaGaO3-based rare earth composite oxides of La0.8Sr0.2Ga0.72Mg0.20Fe0.08O2.8（LSGMF） and La0.8Sr0.2Ga0.72Mg0.20Co0.08O2.8（LSGMC） doped with St, Mg and Fe or Co were synthesized by improved solid reaction method. The composition, phase structure and microstructure of LSGMF and LSGMC samples were analyzed by means of EDS,XRD and SEM. The electrical conductivities of LSGMF and LSGMC as a function of the temperature were measured by DG four-probe technique in the temperature range of 350--850 ℃. The results show that a single phase material of orthorhombic perovskite-type structure was formed after sintering in air at 1 400 ℃ in LSGMF and LSGMC. Other impurity elements were not found except for small amount of Ca in LSGMF and LSGMC samples. The relationship between temperature and the conductivity of LSGMF and LSGMC conformed to the Arrhenius equation in the temperature range of 350 -- 500 ℃ and 500 -- 850 ℃. The activation energies of LSGMF and LSGMC were low at 350- 500 ℃ （Ea d0. 3 eV）. The conductivities of LSGMF and LSGMC were considerably increased compared with Sr, Mg-doped LSGM.