2LiIO3·HIO3的晶体结构与相变

本文用差热分析、热失重以及X射线衍射等方法,对LiIO₃·HIO₃二元系的相平衡进行了研究,观察了以α-LiIO₃为基的固溶体和以2LiIO₃·HIO₃为基的固溶体的热学性质和晶体结构。2LiIO₃·HIO₃属六方晶系,空间群为P6₃,是α-LiIO₃的同晶型结构。20℃的点阵常数为:α=5.555?,c=4. 关键词：

THE CRYSTAL STRUCTURE AND PHASE TRANSITIONS OF 2LiIO3 HIO3

The phase equilibrium of pseudo-binary system LiIO₃-HIO₃ has been investigated by means of DTA, TGA and X-ray diffraction. The thermal properties and crystal structures of solid solutions based on α-LiIO₃ and 2LiIO₃ ·HIO₃ are studied. 2LiIO₃·HIO₃ is isomorphic with α-LiIO₃, belonging to hexagonal system. The space group is P6₃. The lattice parameters are: a=5.555?, c=4.953?. The parameter c decreases and parameter a increases with the HIO₃ content. Compared with α-LiIO₃, IO₃^- group expands along plane x-y and compressed along z-axis, i.e., the bond angle O-I-O becomes larger. 2LiIO₃ ·HIO₃ which is physicochemically different from α-LiIO₃, is a new compound in the system LiIO₃-HIO₃, 2LiIO₃·HIO₃ does not form continuous solid solution with LilO₃.
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