Morphology transformation of barium titanate nanostructures in molten salt medium

Abstract Barium titanate (BaTiO3) nanoparticles undergo a morphological transformation in a NaCl molten salt environment, beginning with nanoparticles then changing to nanowires and then microsheets, while the composition is transformed from pure BaTiO3 into a mixture of Ba2Ti6O13, Na2Ti6O13 and BaTiO3. A systematic study on the effects of calcination temperature, treatment time and the mass ratio of BT (BaTiO3)/NaCl on BaTiO3 nanoparticles morphology is reported. Here, nanowires are generated in the range of 900–1100 °C, while at 1200 °C, not only nanowires but also microsheets appear in the product. Under conditions of 1:100 BT/NaCl weight ratio, 1100 °C calcination temperature, and 3 h reaction time, the resulting nanowires have a smooth surface, with a diameter of 324.6 ± 209.2 nm and a length of 20–150 μm. It is speculated that the mechanism of nanowires formation is a dissolution-precipitation process and that the formation of the microsheets is due to the result of liquid phase sintering of BaTiO3 nanoparticles at high temperature.