Morphology control and large piezoresponse of hydrothermally synthesized lead-free piezoelectric (Bi0.5Na0.5)TiO3 nanofibres

Abstract

Lead-free piezoelectric bismuth sodium titanate (BNT) nanostructures were synthesised using a low-temperature hydrothermal technique. It is found that the phase and morphology of the products are strongly dependent on the composition and concentration of the precursors, as well as the processing conditions. Through optimising the synthesis parameters, well-crystallized BNT nanofibers with 150–200 nm diameters and ∼5 μm length were obtained. The BNT fibres show a pure perovskite phase with (011) orientation along the length direction. A piezoelectric constant of d₃₃ = ∼15 pm V⁻¹ in the diameter direction was observed for these BNT nanofibers.