9R-BaMnO_3单晶的水热合成与表征

Hydrothermal Synthesis and Characterization of Single Crystal of 9R-BaMnO_3

在水热条件下,成功制备了具有钙钛矿结构的9R-BaMnO_3单晶,利用强碱作为媒介进行合成。利用X射线单晶衍射对样品的结构进行分析,结果经过结构精修后得到化合物的结构是由9个AO_3四面体沿着六重轴方向进行密堆积而成。晶体为菱方晶格,a=0.566 5(0)nm,c=2.092 2(4)nm,空间群为R-3m,扫描电镜照片显示单晶晶体尺寸在70μm左右。在4~300K的温度区间内,9R-BaMnO_3呈现反铁磁行为。

The single crystals of 9R-BaMnO_3 with perovskite structure were successfully prepared under hydrothermal conditions.The crystal structure was determined by single crystal X-ray diffraction method.The refined single crystal structure exhibited that the structure consisted of nine close packed(AO_3)layers stacked along the hexagonal axis.The crystals were rhombohedral with hexagonal axes(a=0.566 5(0)nm and c=2.092 2(4)nm).The space group was R-3m.The scanning electron microscope(SEM)photographs showed that the crystal size was about 70μm.9R-BaMnO_3 showed antiferromagnetic behavior from 4to 300 K.