通过顺序插层在钙钛矿主体中构建碱金属卤化物层：(A₂Cl)LaNb₂O₇（A = Rb，Cs）

Building alkali-metal-halide layers within a perovskite host by sequential intercalation: (A(2)Cl)LaNb(2)O(7) (A = Rb, Cs).

作者信息

Choi Jonglak, Zhang Xiao, Wiley John B

机构信息

Department of Chemistry and the Advanced Materials Research Institute, University of New Orleans, New Orleans, Louisiana 70148, USA.

出版信息

Inorg Chem. 2009 Jun 1;48(11):4811-6. doi: 10.1021/ic802344b.

DOI:10.1021/ic802344b

PMID:19466802

Abstract

Alkali-metal-halide layers were constructed within Dion-Jacobson (DJ) layered perovskites by a two-step sequential intercalation method. Reductive intercalation with an alkali metal, followed by oxidative intercalation with chlorine gas, leads to the formation of the compounds, (A(2)Cl)LaNb(2)O(7) (A = Rb, Cs). Rietveld refinement of X-ray powder diffraction data shows that an alkali-metal-halide layer is formed between the perovskite blocks. The alkali-metal cation is eight-coordinate with four oxygens from the perovskite layer and four chlorides from the new halide layer; this environment is similar to cesium in the CsCl structure (B2). Thermal analysis indicates that these are low-temperature phases where decomposition begins by 400 degrees C. Details on the synthesis and characterization of this set of compounds are presented, and the general utility of this approach discussed.

摘要

通过两步顺序插层法在狄翁-雅各布森（DJ）层状钙钛矿中构建了碱金属卤化物层。先用碱金属进行还原插层，然后用氯气进行氧化插层，导致形成化合物(A₂Cl)LaNb₂O₇（A = Rb、Cs）。对X射线粉末衍射数据进行的Rietveld精修表明，在钙钛矿块之间形成了碱金属卤化物层。碱金属阳离子与来自钙钛矿层的四个氧原子和来自新卤化物层的四个氯原子形成八配位；这种环境类似于CsCl结构（B2）中的铯。热分析表明，这些是低温相，在400℃时开始分解。本文介绍了这组化合物的合成和表征细节，并讨论了该方法的普遍适用性。