Structural and electrical properties of excess PbO doped Pb(Zr_(0.48)Ti_(0.52)O_3 thin films prepared by a MOD process

摘要

Pb(Zr_(0.48)Ti_(0.52)O_3 thin films with 30 mol percent excess Pb were deposited on Pt/Ti/SiO_2/Si(100) substrates at 600 deg C by a metal-organic decomposition process. The Pb/Zr ratio measured by Rutherford backscattering spectroscopy is higher than the stoichiometric ratio. X-ray diffraction measurements show than the PZT film has a perovskite structure but it also contains a PbO_2 phase High resolution transmission electron microscope studies reveal that the nano sized PbO_2 crystals are dispersed quite uniformly in the films. The film exhibits an abnormally slim polarization loop at low applied electric field probably as a result of domain pinning by the PbO_2 crystals. The pinning effect can be overcome by applying a sufficiently high field. The film has good fatigue properties even with the presence of the PbO_2 crystals.