Doping and phase transformation of single-crystal pre-perovskite PbTiO3 fibers with TiO6 edge-shared octahedra

Abstract

Ba-doped (0–8 mol%) pre-perovskite PbTiO₃ single-crystal fibers have been synthesized in large-scale reproducibly by a facile polymer-assisted hydrothermal method. X-ray power diffraction, scanning electron microscope and transmission electron microscope were performed to investigate microstructure and the evolution of these single-crystal fibers. The results show that these fibers have a length of 13–120 μm and a diameter of 100–600 nm. In particular, these Ba-doped pre-perovskite PbTiO₃ fibers can transform to tetragonal perovskite Ba-doped PbTiO₃ (PBT) fibers with single-crystal character. Piezoresponse force microscopy measurements indicate that the perovskite PBT with Ba concentration of 5 mol% has a symmetric “square” phase loop, and the amplitude loop shows a “butterfly shape”, confirming the existence of ferroelectric and piezoelectric properties. Such findings have thus provided a promising route for the nanoscale sensors and generators applications.