Synthesis of Single-Crystalline Niobate Nanorods via Ion-Exchange Based on Molten-Salt Reaction

One-dimensional (1D) nanostructures of ternary complex oxides have drawn intensive interest because of their novel size-dependent properties, such as ferroelectric,1a multiferroic,1b and superconduc-tivity.1c Various synthetic approaches, such as aqueous route by employing hydrothermal reaction2 or templates,3 molten-salt syn-thesis,4 and composite-hydroxide-mediated synthesis5 have been developed for the synthesis of different kinds of ternary metal oxides 1D nanostructures, for example, alkali titanates,6 peroskite-type ferroelectric titanates,7,4c vanadates,8 niobates,9 and ABO4-type chromates and tungstates.10 Alkali and alkali earth niobates might exhibit excellent nonlinear optical and dielectric properties, on the basis of which novel nanodevices might be designed by utilizing their 1D nanostructures. For example, subwavelength optical microscopy by employing tunable nanometric light source based on KNbO3 nanowires wer