Ferroelectric Mesocrystalline BaTiO3/SrTiO3 Nanocomposites with Enhanced Dielectric and Piezoelectric Responses

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• 作者：Dengwei Hu ; Hao Ma ; Yasuhiro Tanaka ; Lifang Zhao ; Qi Feng
• 刊名：Chemistry of Materials
• 出版年：2015
• 出版时间：July 28, 2015
• 年：2015
• 卷：27
• 期：14
• 页码：4983-4994
• 全文大小：825K
• ISSN：1520-5002

文摘

A platelike mesocrystalline BaTiO₃/SrTiO₃ (BT/ST) nanocomposite is prepared via a clever two-step solvothermal soft chemical process. First a protonated titanate H_1.07Ti_1.73O₄路nH₂O (HT) crystal with a layered structure and platelike morphology is solvothermally treated in a Ba(OH)₂ solution to generate a homogeneous platelike BaTiO₃/HT (BT/HT) nanocomposite. Second the generated BT/HT nanocomposite is solvothermally treated in a Sr(OH)₂ solution to generate the mesocrystalline BT/ST nanocomposite with platelike particle morphology. The transformation reactions from the HT precursor to the mesocrystalline BT/ST nanocomposite are topochemical conversion reactions, and the formed BT/ST nanocomposite is constructed from well-aligned BT and ST nanocrystals in the same crystal-axis orientation. The BT/ST nanocomposite annealed at 900 掳C shows a ferroelectric behavior and drastically enhanced piezoelectric and dielectric responses owing to the introduction of a lattice strain at a three-dimensional heteroepitaxial interface between the BT and ST nanocrystals in the mesocrystal. The nanostructure of the BT/ST mesocrystal is suitable for simultaneous application of the strain engineering and the orientation engineering to develop high performance piezoelectric and dielectric materials.