Morphology Control of BaTiO₃ Nanoparticles Prepared by Sol-gel Hydrothermal Method

Barium titanate (BT), a typical ferroelectric material with a tetragonal structure bellow TC ≈125 ºC has found widespread applications especially in electronic devices. However, modern electronics demand very small functional structures and, as a consequence nanostructures of ferroeletrics are being considered. However it was observed that there is a critical size for BT nanostructures below which TC decreases, the paraelectric cubic phase is stabilized at room temperature and then ferroelectricity may no longer exist. These observations have stimulated an exponential growth of research aiming to understand the effect of scaling on the ferroelectric properties. In addition some theoretical studies predicted the enhancement of ferroelectricity in anisotropic “cylindrical” shaped nanoparticles. Therefore, the morphology control and fabrication of ferroelectric nanostructures with different size and shapes are of key importance. Within this context, we demonstrated that the control of the morphology of BT nanoparticulates can be achieved by hydrothermal method.