Structure and Piezoelectric Properties of Lead-Free Na0.5Bi0.5TiO3 Nanofibers Synthesized by Electrospinning

Lead-free Na0.5Bi0.5TiO3 (NBT) nanofibers with the perovskite structure were prepared by the electrospinning method. The nanofibers were about 200-300 nm in diameter and up to several hundred microns in length. The crystal structures and morphologies of the nanofibers were characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The effective piezoelectric property of individual NBT nanofiber was examined by piezoresponse force microscopy (PFM). The NBT nanofibers crystallized in pure perovskite phase after annealing above 700 °C in air and comprised a great number of fine particles with size of 60-80 nm. In addition, the electromechanical energy conversion models for NBT nanofibers were built and demonstrated high voltage output as high as several millivolts. Such a result qualifies NBT nanofibers as a promising candidate for lead-free electromechanical conversion devices.