WANG Zhiqi ¹, ZHAO Jie ¹, BAO Juncheng ¹, MA Xu ¹, LI Jianpin ²

(1.School of Materials Sci. and Eng., Tianjin University of Technology, Tianjin 300191; 2.Rolling Technique and Tandem Automation National Key Laboratory, Northeastern University,Shenyang 110004)

Abstract: Compositely Doped Oxide La_0.8Sr_0.2Ga_0.8Mg_0.17O_2.5(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(<1eV=. The ionic conductivity of LSGMF201703 ishigher than that of LSGM2025 in testing temperature range.Thus, proper amount of Sr and Mg doping is beneficial to hig ionic conductivity.

Keywords:  perovskite structure, oxygen ion conductor, lanthanum gallate, ionic conductivity