Department of Chemistry, Oregon State University, Corvallis, Oregon 97331, USA.
Inorg Chem. 2011 Sep 5;50(17):8494-501. doi: 10.1021/ic2010375. Epub 2011 Jul 27.
Structures of CsTe₂O(6-x) phases were investigated by single-crystal X-ray diffraction and neutron powder diffraction. Stoichiometric CsTe₂O₆ is a mixed-valence Cs₂Te⁴⁺Te₃⁶⁺O₁₂ compound with a rhombohedral pyrochlore-type structure where there is complete order of Te⁴⁺ and Te⁶⁺. On heating, this compound develops significant electrical conductivity. As CsTe₂O₆ becomes oxygen deficient above 600 °C, the rhombohedral pyrochlore-type structure is replaced by a cubic pyrochlore-type structure with disordered Te⁴⁺/Te⁶⁺ and oxygen vacancies. However, for CsTe₂O(6-x) phases prepared at 500 °C, the observed pyrochlore-type structure has symmetry. The Te⁴⁺ and O vacancies are all on chains running along the b axis, and the maximum value of x observed is about 0.3. At still higher values of x a new compound was discovered with a structure related to that reported for Rb₄Te₃⁴⁺Te₅⁶⁺O₂₃.
通过单晶 X 射线衍射和中子粉末衍射研究了 CsTe₂O(6-x) 相的结构。化学计量比的 CsTe₂O₆ 是一种具有菱方烧绿石型结构的混合价态 Cs₂Te⁴⁺Te₃⁶⁺O₁₂化合物，其中 Te⁴⁺和 Te⁶⁺完全有序。在加热时，该化合物具有显著的导电性。当 CsTe₂O₆ 在 600°C 以上失去氧气时，菱方烧绿石型结构被具有无序 Te⁴⁺/Te⁶⁺和氧空位的立方烧绿石型结构所取代。然而，对于在 500°C 下制备的 CsTe₂O(6-x) 相，观察到的烧绿石型结构具有对称性。Te⁴⁺和 O 空位都在沿 b 轴延伸的链上，观察到的 x 的最大值约为 0.3。在更高的 x 值下，发现了一种具有与 Rb₄Te₃⁴⁺Te₅⁶⁺O₂₃ 报道的结构相关的新化合物。
