Topochemical build-up of BaTiO3 nanorods using BaTi2O5 as the template

Abstract

One-dimensional BaTiO₃ nanomaterials have important applications in nano-ferroelectric devices, and their high-quality synthesis is a hotspot in the field of chemistry of materials. In this work, single-crystalline perovskite BaTiO₃ nanorods have been prepared by a two-step molten salt method. The conversion process and the topochemical mechanism were investigated based on XRD, DSC, SEM and TEM analysis. Firstly, one dimensional BaTi₂O₅ nanocrystallites have been synthesized in a molten environment and the self-polarization effect is responsible for the growth direction of [0 2 0]. Then, using these oriented BaTi₂O₅ monoclinic nanorods as templates, BaTiO₃ perovskite nanorods have been further constructed through the topochemical reaction, in which all edge-sharing [TiO₆] octahedra converted into corner-sharing modes to obtain the minimum energy state. One-dimensional morphology of BaTiO₃ can only be obtained at a low calcination temperature, because at a high temperature, it will decompose into nanoparticles. This topological method is facile and can be developed to construct other orientated functional materials.