复合掺杂氧化物La_(1-x)Sr_xGa_(1-y)Mg_yO_(3-δ)的结构与电性能研究

Study on structure and electrical property of compositely doped oxide La_(1-x)Sr_xGa_(1-y)Mg_yO_(3-α)

用固相反应法合成低价离子Sr、Mg复合掺杂的ABO3型氧化物La0.9Sr0.1Ga0.85Mg0.15O2.875（LSGMl015）La0.9Sr0.1Ga0.75Mg0.25O2.825（LSGM1025）；借助EDS、XRD、SEM、直流四电极法等对LSGM1015和LSGM1025的微区成分、晶体结构、断面显微组织及导电性等进行研究．EDS和XRD分析表明：合成的LSGM1015和LSGM1025样品中杂质元素很少，且具有正交钙钛矿结构，基本上不合杂相；电导率测试结果表明：在673-1073K温度区间，其电导率与温度的关系符合Arrhenius定律，说明LSGM1015和LSGM1025为氧离子导体，且离子迁移活化能Ea≈1eV；Sr、Mg复合掺杂量较多（x＋y=0．35）的LSGM1025具有较高的离子电导率．

Compositely Doped Oxide La0.9Sr0.1Ga0.85 Mg0.15O2.875 （ LSGM1015 ） and La0.9Sr0.1Ga0.75 Mg0.25 O2.825（ LSGM1025 ） were synthesized by solid state reaction method. The composition, crystal structure, ionic conductivity and microstructure of LSGM1015 and LSGM1025 samples were analyzed by Using EDS, XRD,DC four-probe and SEM. EDS and XRD show that LSGMIO15 and LSGM1025 with low content of impurity possess orthorhombic perovskite-type structure ,and impurity phases have not been found in them. Electrical measurement results show that LSGM1015 and LSGM1025 are oxygen ion conductors based on the fact that temperature dependence of the conductivity conforms to the Arrhenius equation in 673 - 1073 K, and that they have similar activation energy （ Ea ≈ 1 eV）. LSGM1025 （x ＋ y =0.35） has higher ionic conductivity than LSGM1015.