The dimorphism of LiMnFeF6: A new kind of cationic order in the structural type Na2SiF6
The dimorphism of LiMnFeF6: A new kind of cationic order in the structural type Na2SiF6
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LiMnFeF6的二态性：结构类型Na2SiF6中的一种新的阳离子顺序
DOI：
10.1016/0022-4596(82)90299-7
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发表时间：
1982
影响因子：
3.3
通讯作者：
R. Pape
中科院分区：
文献类型：
--
作者：
G. Courbion;C. Jacoboni;R. Pape
LiMnFeF 6具有二型性，α → β转变温度为560°C。两相均为三方对称（空间群P321，Z= 3），晶胞数据非常接近：aα= 8.684（2），cα= 4.657（1），aβ= 8.723（2），cβ= 4.745（1）.由单晶X射线衍射数据确定了α-LiMnFeF 6的绝对结构（R= 0.020）。这种结晶形式在结构类型Na 2SiF 6中表现出一种新的阳离子顺序。通过X射线衍射和中子粉末衍射数据确定了β-LiMnFeF 6的阳离子分布，该化合物具有LiMnGaF 6的结构。讨论了与Na_2SiF_6型有关的各种阳离子分布，并对Li（Na）MIIMIIIF_6进行了分类。
LiMnFeF6shows a dimorphism; the transition temperature α → β occurs at 560°C. The symmetry of the two phases is trigonal (space groupP321,Z= 3) and the unit cell data are very close to each other:aα= 8.684(2),cα= 4.657(1),aβ= 8.723(2),cβ= 4.745(1) Å. The absolute structure of α-LiMnFeF6was determined from single-crystal X-ray data (R= 0.020). This crystalline form exhibits a new kind of cationic order in the structural type Na2SiF6. The cationic distribution of β-LiMnFeF6was specified from X-ray and neutron powder diffraction data; this compound is isotypical with the LiMnGaF6structure. The different kinds of cationic distribution related to the Na2SiF6type are discussed and a classification of the compounds Li(Na)MIIMIIIF6is given.