六方类钙钛矿体系La_(2-x)Nd_xCa_2MnO_7的结构和相关系

Structure Variation in the Hexagonal Perovskite System La_(2-x)NdxCa_2MnO_7

利用柠檬酸盐前驱物法制备了La2-xNdxCa2MnO7系列样品,并利用Rietveld方法对结构进行了精修。结果表明:体系中存在两个单相区(x≤1.0,x≥1.5)和一个两相区(1.0<x<1.5)。体系这种结构变化可以用稀土离子半径变化说明。

La2-xNdxCa2MnO7 samples were prepared from citric acid sol-gel precursor using solid state reaction. The cell parameters of these samples were refined using Rietveld method, which evidence the presence of single-phase regions ( x less than or equal to 1.0 and x greater than or equal to 1.5) and two-phase region 1.0 < x < 1.5. The structure variation of this system can be understood by considering the ionic size of rare earth cation.