Abstract The temperature-dependent structure-property relationships of the aluminosilicate perrhenate sodalite |Na8(ReO4)2|[AlSiO4]6 (ReO4-SOD) were analysed via powder X-ray diffraction (PXRD), Raman spectroscopy and heat capacity measurements. ReO4-SOD shows two phase transitions in the investigated temperature range (13 K < T < 1480 K). The first one at 218.6(1) K is correlated to the transition of dynamically ordered P 4 ¯ 3 n $P\overline{4}3n$ (> 218.6(1 K) to a statically disordered (<218.6(1) K) SOD template in P 4 ¯ 3 n $P\overline{4}3n$ . The loss of the dynamics of the template anion during cooling causes an increase of disorder, indicated by an unusual intensity decrease of the 011-reflection and an increase of the Re-O2 bond length with decreasing temperature. Additionally, Raman spectroscopy shows a distortion of the ReO4 anion. Upon heating the thermal expansion of the sodalite cage originated in the tilt-mechanism causes the second phase transition at 442(1) K resulting in a symmetry-increase from P 4 ¯ 3 n $P\overline{4}3n$ to P m 3 ¯ n $Pm\overline{3}n$ , the structure with the sodalites full framework expansion. Noteworthy is the high decomposition temperature of 1320(10) K.

中文翻译：

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铝硅酸盐高铼方钠石相变的性质

摘要 通过粉末X射线衍射(PXRD)、拉曼光谱和热容量测量分析了高铼铝硅酸盐方钠石|Na8(ReO4)2|[AlSiO4]6 (ReO4-SOD)的温度依赖性结构-性质关系。ReO4-SOD 在所研究的温度范围内 (13 K < T < 1480 K) 显示出两个相变。第一个在 218.6(1) K 与动态有序 P 4¯ 3 n $P\overline{4}3n$ (> 218.6(1 K) 到静态无序 (<218.6(1) K) 的转换相关P 4 ¯ 3 n $P\overline{4}3n$ 中的 SOD 模板。冷却过程中模板阴离子动力学的丧失导致无序度的增加，表现为 011 反射强度异常降低和Re-O2 键长随温度降低。此外，拉曼光谱显示了 ReO4 阴离子的畸变。加热时，源自倾斜机制的方钠石笼的热膨胀导致 442(1) K 处的第二相变，导致对称性从 P 4 ¯ 3 n $P\overline{4}3n$ 增加到 P m 3¯ n $Pm\overline{3}n$ ，方钠石全骨架展开的结构。值得注意的是1320（10）K的高分解温度。