Constitution of network structures with large. inner spaces with antimonate ions

研究了由锑和铟氧化物构成的网络结构，合成了一种新的化合物LiIn_2SbO_6。我们测量了X射线和中子粉末衍射数据，并通过Rietveld分析确定了它的晶体结构。结构没有杂乱，李遗址的空间也没有想象中的那么大。另一方面，当使用较大的碱金属如钾代替锂时，形成具有较大隧道的奥朗德型结构的锑-铟氧化物网络。此外，该氧化锑网络不仅可以包括铟，还可以包括过渡元素。我们还对烧绿石中的大空洞结构感兴趣，并研究了ASbWO_6体系（A：碱性元素）。以钠为碱金属时，虽然已有立方烧绿石结构和正交结构的化合物报道，但NaSbWO_6的形成是一种新的形式。粉末X射线衍射数据的Rietveld分析表明，新晶体的结构与正交LiSbWO_6类似，但具有一种新的单斜结构，其结构与正交结构略有不同。当锂被用作碱性元素时，得到了具有类似烧绿石结构的氧化物，并且该结构与所报道的不同。这些实验结果表明，由合成反应构建的锑氧化物体系的网络结构不仅限于那些化学上最稳定的。因此，如果我们能找到合适的合成方法，我们可以用锑氧化物体系构建广泛的网络结构。

Investigation of the network structures constructed with antimony and indium oxides led to the synthesis of a new compound LiIn_2SbO_6. We measured the X-ray and neutron powder diffraction data, and determined its crystal structure by Rietveld analysis. The structure had no disorder and the space of the Li site was not so large as expected. On the other hand, when larger alkali metals like potassium were used instead of lithium, antimony-indium oxide networks of the hollandite-type structure with larger tunnels were formed. Furthermore, the antimony-oxide network of the hollandite-type could include not only indium but also transition elements. We were interested also in the pyrochlore structures with large cavities, and investigated ASbWO_6 systems (A: alkaline elements). If sodium was used as the alkaline element, a new form of NaSbWO_6 was formed though the compounds with the cubic pyrochlore structure and an orthorhombic structure had been reported. The Rietveld analysis of the powder X-ray data of the new form showed that the structure was similar to the orthorhombic LiSbWO_6 but had a new monoclinic structure slightly deformed from the orthorhombic structure. When lithium was used as the alkaline element, an oxide with a pyrochlore-like structure was obtained, and the structure was different from the reported one. These experimental results indicated that the network structures with antimony oxide systems constructed by the synthetic reactions were not confined only in those that were thermodynamically most stable. Therefore, if we could find suitable synthetic procedures, we could build a wide range of network structures with antimony oxide systems.