Self-Recovery of Defective PbTiO₃ Film with Enhanced Piezoelectricity by Homogenizing Annealing

Abstract

Impurity defects are often involved in the growth of thin films by pulsed laser deposition (PLD), which is intrinsically a nonequilibrium process governed by competition between kinetics and thermodynamics. Generally, the growth of oxide films by PLD will introduce defects and/or impurities which lead to the degradation of related properties. Here we show that postannealing could cure defective PbTiO 3 (PTO) thin films grown by PLD. A series of PTO thin films were grown on (001) SrTiO 3 (STO) under low oxygen pressure and further investigated by piezoelectric force microscopy (PFM) and (scanning) transmission electron microscopy ((S)TEM). It was found that there are many impurity defects buried in the PTO films. These films were annealed at different temperatures. The defects completely vanished after annealing at 700 °C in the furnace, following a significant recovery. The significance of this Article is not only to provide a method for eliminating low-dimension defects, but also to provide an understanding of coupling relationship between defect-domain walls.