title: Atomic-scale control of TiO₆ octahedra through solution chemistry towards giant dielectric response.
abstract: 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.
authors.affiliation: 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.
authors.forename: Wanbiao
authors.initials: W
authors.lastname: Hu
authors.affiliation: State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, P. R. China.
authors.forename: Liping
authors.initials: L
authors.lastname: Li
authors.affiliation: State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, P. R. China.
authors.forename: Guangshe
authors.initials: G
authors.lastname: Li
authors.affiliation: Research School of Chemistry, The Australian National University, ACT 0200, Australia.
authors.forename: Yun
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Research School of Chemistry, The Australian National University, ACT 0200, Australia.
authors.forename: Ray L
authors.initials: RL
authors.lastname: Withers