Hu Wanbiao, Li Liping, Li Guangshe, Liu Yun, Withers Ray L
1] State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, P. R. China [2] Research School of Chemistry, The Australian National University, ACT 0200, Australia.
State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, P. R. China.
Sci Rep. 2014 Oct 10;4:6582. doi: 10.1038/srep06582.
The structures of many important functional oxides contain networks of metal-oxygen polyhedral units i.e. MOn. The correlation between the configurations and connectivities of these MOn to properties is essentially important to be well established to conduct the design, synthesis and application of new MOn-based functional materials. In this paper, we report on an atomic-scale solution-chemistry approach that for the first time enables TiO₆ octahedral network control starting from metastable brookite TiO₂ through simultaneously tuning pH values and interfering ions (Fe(3+), Sc(3+), and Sm(3+)). The relationship between solution chemistry and the resultant configuration/connectivity of TiO₆ octahedra in TiO₂ and lepidocrocite titanate is mapped out. Apart from differing crystalline phases and morphologies, atomic-scale TiO₆ octahedral control also endows numerous defect dipoles for giant dielectric responses. The structural and property evolutions are well interpreted by the associated H(+)/OH(-) species in solution and/or defect states associated with Fe(3+) occupation within TiO₆ octahedra. This work therefore provides fundamental new insights into controlling TiO₆ octahedral arrangement essential for atomic-scale structure-property design.
许多重要功能氧化物的结构包含金属-氧多面体单元网络，即MOn。这些MOn的构型和连接性与性能之间的关联对于开展新型基于MOn的功能材料的设计、合成及应用而言，确立得足够完善至关重要。在本文中，我们报道了一种原子尺度的溶液化学方法，该方法首次能够通过同时调节pH值和干扰离子（Fe(3+)、Sc(3+)和Sm(3+)），从亚稳的板钛矿TiO₂出发实现TiO₆八面体网络控制。绘制出了溶液化学与TiO₂和钛酸纤铁矿中TiO₆八面体的最终构型/连接性之间的关系。除了不同的晶相和形貌外，原子尺度的TiO₆八面体控制还赋予了大量用于巨大介电响应的缺陷偶极子。结构和性能演变通过溶液中相关的H(+)/OH(-)物种和/或与TiO₆八面体内Fe(3+)占据相关的缺陷态得到了很好的解释。因此，这项工作为控制TiO₆八面体排列提供了全新的基础见解，这对于原子尺度的结构-性能设计至关重要。
