General Approach to Well-Defined Perovskite MTiO3 (M = Ba, Sr, Ca, and Mg) Nanostructures

Well-defined perovskite MTiO 3 (M = Ba, Sr, Ca and Mg) nanostructures were successfully synthesized by a convenient hydrothermal method, employing MCl 2 as M source and titanate nanowire as Ti precursor. Different perovskite nanostructures such as nanoring, nanobowl, nanotube, and nanodisk were successfully prepared. Two types of growth mechanisms were proposed by investigating the formation processes of MTiO 3 nanostructures. The formation of MTiO 3 (M = Ba and Sr) undergoes a “nanowire−tube−ring” growth mechanism with a self-sacrifice of titanate nanowire framework rout, whereas the formation of CaTiO 3 and MgTiO 3 structures follows a simultaneous epitaxial growth of TiO 2 nanotube on titanate nanowire and self-nucleation of MTiO 3 (M = Mg and Ca) in the solution initially, and then a conversion of the nanowire and nanotube to MgTiO 3 /CaTiO 3 nanostructure process. The electrical properties of the perovskite MTiO 3 nanostructure including polarization-field hysteresis and capacitance−voltage characteristics were also investigated.