Domain configuration and interface structure analysis of sol-gel-derived PZT ferroelectric thin films

The domain configuration and interfacial structure of sol-gel-derived PZT thin films were evaluated using atomic force microscopy and x-ray photoelectron spectroscopy. Microstructure and ferroelectric property investigation of the PZT thin films under repeated a.c. field suggests that microcracks may be the major cause for ferroelectric fatigue. The intersection of 90 degrees domain walls, where the concentration of stress occurs, is likely to be the origin of microcracks. In addition, the entrapment of defects at domain walls, grain boundaries and/or PZT/electrode interface due to relatively lower potential energy at these sites results in an internal field with a direction opposite to the applied field, which weakens the electric field intensity in the PZT thin films. A fraction of the domains is pinned and finally results in polarization fatigue of the PZT thin films. Copyright (C) 2001 John Wiley & Sons, Ltd.