Crystal structures of the compounds Sm2AlGe3 and Tb2AlGe3
Crystal structures of the compounds Sm2AlGe3 and Tb2AlGe3
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DOI：
10.1016/j.jallcom.2004.02.065
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发表时间：
2005-07
影响因子：
6.2
通讯作者：
I. Melnyk;V. Kuprysyuk;R. Gladyshevskii;S. Pikus;P. Staszczuk
中科院分区：
文献类型：
--
作者：
I. Melnyk;V. Kuprysyuk;R. Gladyshevskii;S. Pikus;P. Staszczuk
用X-射线粉末衍射法测定了两个新的稀土锗铝化合物Sm{sub2}AlGe{sub3}和Tb{sub2}Alge{sub3}的结构(R{subB}分别为0.066和0.064)。这些化合物具有Y{sub2}AlGe{sub3}型，OP24(62)Pnma-c{sup 6}，a=6.8153(4)，b=4.2723(3)，c=17.9491(10)A(R=Sm)和a=6.7749(4)，b=4.1980(3)，c=17.7222(10)A(R=Tb)，Z=4.三分之二的Ge原子位于R{sub6}三面体的中心，而其余的Ge原子占据R{sub4}四面体的中心.已知的其他四个化合物具有相同的结构类型，R=Dy，Ho，Er和Tm，但Sm{sub2}Alge{sub3}是第一个同型化合物的例子，其中R是轻稀土元素。
The structures of two new rare-earth aluminum germanides, Sm{sub 2}AlGe{sub 3} and Tb{sub 2}AlGe{sub 3}, were determined from X-ray powder diffraction data (R {sub B} = 0.066 and 0.064, respectively). These R{sub 2}AlGe{sub 3} compounds crystallize with orthorhombic structures of the Y{sub 2}AlGe{sub 3} type, oP24 (62) Pnma - c {sup 6}, a = 6.8153(4), b = 4.2723(3), c = 17.9491(10) A (R = Sm) and a = 6.7749(4), b = 4.1980(3), c = 17.7222(10) A (R = Tb), Z = 4. Two-thirds of the Ge atoms are situated at the centers of R{sub 6} trigonal prisms, whereas the other Ge atoms occupy the centers of R{sub 4} tetrahedra. Four other compounds are known to crystallize with the same structure type, R = Dy, Ho, Er and Tm, but Sm{sub 2}AlGe{sub 3} is the first example of an isotypic compound where R is a light rare-earth element.