Studies Of The Structure Characterizations About Perovskite Diphase LSCF And Synthisis Of K₂NiF₄-Type Materials

It is demanded that we must develop intermediate solid oxide fuel cells (ITSOFC), especially research the cathode materials with better performances. According to the experimental results before, we know that perovskite La_0.6Sr_0.4Co_0.2Fe_0.8O₃ shows best physical and chemical performances when used with an yttria-stabilised zirconia(YSZ) electrolyte, but still possess disadvantages such as the contradiction between thermal expansion coefficients and mixed conductivities which are both related with doped atoms of A-site. After in all, there are two ways to solve this problem, one to mix materials with good electronic conductivities and good ionic conductivities separately, another to research new replacement materials.The studies of this paper are synthesis of diphase La_1-xSr_xCo_1-yFe_yO₃ in the experiment, and especially we focus on the progresses, factors and mechanism of formations about diphase compound perovskite. In order to discuss the possibilities of best performances of this diphase perovskite materials shown as cathode of IT-SOFC, a Rietveld method was applied to do the structure refinements and to calculate the crystal parameters of diphase materials.In this paper, we also do some preceding work on new material of K₂NiF₄ type La₂Ni_1-xM_xO₄(M=Cu, Fe, Co). That is we have tried to prepare materials by EDTA sol-gel method less reported in references, and concluded the suit steps of heat treatments of every precursors for deep systemic physical and chemical researches in the later.