Raman Spectra of the Solid-Solution between Rb2La2Ti3O10 and RbCa2Nb3O10

Bulletin of the Korean chemical society

Song-Ho Byeon¹  Hoseop Yun¹  Hee Jin Kim¹ 

关键词: Layered structure;    Oxides;    Raman spectra;    Site preference.;   

DOI  :  

学科分类：化学（综合）

来源: Korean Chemical Society

【 摘 要 】

A site preference of niobium atom in Rb_2-xLa₂Ti_3-xNb_xO₁₀ (0.0 ÷ x ÷1.0) and RbLa_2-xCa_xTi_2-xNb_1+xO₁₀ (0.0 ÷ x ÷2.0), which are the solid-solutions between Rb₂La₂Ti₃O₁₀ and RbCa₂Nb₃O₁₀, has been investigated by Raman spectroscopy. The Raman spectra of Rb_2-xLa₂Ti_3-xNb_xO₁₀ (0.0 ÷ x ÷1.0) gave an evidence that niobium atoms substituted for titanium atoms preferably occupy the highly distorted outer octahedral sites rather than the central ones in triple-octahedral perovskite layers. In contrast, the Raman spectra of RbLa_2-xCa_xTi_2-xNb_1+xO₁₀ (0.0 ÷x ÷2.0) showed no clear information for the cationic arrangement in perovskite slabs. This difference indicated that a site preference of niobium atoms is observed only when the linear Rb-O-Ti linkage can be replaced by much stronger terminal Nb-O bond with double bond character. From comparison with the Raman spectroscopic behavior of CsLa_2-xA�?_xTi_2-xNb_1+xO₁₀ (A�? = Ca and Ba; 0.0 ÷x ÷2.0), it is also proposed that a local difference in arrangement of interlayer atoms causes a significantly different solid acidity and photocatalytic activity of the layered perovskite oxides, despite their crystallographically similar structures.

【 授权许可】

Unknown