Three-dimensional oriented attachment growth of single-crystal pre-perovskite PbTiO3 hollowed fibers

Abstract

Hollowed single-crystal pre-perovskite PbTiO₃ fibers (PP-PTF) were successfully synthesized via a polyvinyl alcohol (PVA) assisted hydrothermal process. The as-prepared PP-PTF were characterized to be 0.3–1 μm in diameter and tens of micrometers in length by adjusting the concentration of PVA to 0.8 g L⁻¹. Microstructure characterization of the samples at different reaction times revealed that PP-PTF were formed via a three-dimensional (3D) hierarchical oriented attachment (OA) growth process. The initial growth units were determined to be single-crystal pre-perovskite PbTiO₃ fibers with a diameter of 10–20 nm. Zeta potential measurement suggested that the main driving force of the OA process is the surface electrostatic force, which is induced by the incompletely bonded Pb and O atomic layers on the surface of the {110} plane. Moreover, molecular dynamics simulations have been employed to reveal a stable configuration of the initial pre-perovskite PbTiO₃ growth units, agreeing well with the experimental results.