Building alkali-metal-halide layers within a perovskite host by sequential intercalation: (A(2)Cl)LaNb(2)O(7) (A = Rb, Cs).
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.
Choi
Jonglak
J
Department of Chemistry and the Advanced Materials Research Institute, University of New Orleans, New Orleans, Louisiana 70148, USA.
Zhang
Xiao
X
Wiley
John B
JB