La1-xCaxMn0.96Fe0.04O3（x=0.31、0.5、0.6）的中子衍射研究

La_1-xCa_xMn_0.96Fe_0.04O₃（x=0.31、0.5、0.6）的中子衍射研究

摘要: 利用Rietveld分析方法对钙钛矿锰氧化物La_1-xCa_xMn_0.96Fe_0.04O₃（x=0.31、0.5、0.6）室温下中子衍射实验数据进行拟合。结果表明，La_1-xCa_xMn_0.96Fe_0.04O₃化合物具有MnO₆八面体，空间群为Pnma，La（Ca）原子占据4c晶位，Mn（Fe）原子占据4b晶位，O原子分别占据4c和8d晶位。根据拟合结果，计算出Mn-O键的键长和Mn-O-Mn的键角，并对该系列样品结构和磁性能间的关系进行了简单讨论。

Abstract: The crystallographic structures of perovskite manganites La_1-xCa_xMn_0.96Fe_0.04O₃（x=0.31,0.5,0.6） were refined by Rietveld analysis of neutron diffraction data at room temperature. The refined results indicate that La_1-xCa_xMn_0.96Fe_0.04O₃（x=0.31,0.5,0.6） compound has MnO₆ type (space group: Pnma) octahedral shape. The La/Ca atoms prefer to 4c sites, the Mn/Fe atoms prefer to 4b sites, and the O atoms prefer to 4c and 8d sites. The Mn-O bond distances and the Mn-O-Mn angles were obtained. The relationship between magnetic properties and structures is discussed.