%0 Journal Article %K thin films %K Electric fields %K Polarization %K Domain walls %K Switching %K Ferroelectric films %K Ferroelectric thin films %K Piezoresponse force microscopy %K Bottom electrodes %K Depolarizing fields %K In-plane polarization %K Initial orientation %K Out-of-plane %K Polydomain %K Transient polarization %K Depolarization %A A Roelofs %A N.A Pertsev %A R Waser %A F Schlaphof %A L.M Eng %A C Ganpule %A V Nagarajan %A Ramamoorthy Ramesh %B Applied Physics Letters %D 2002 %G eng %P 1424-1426 %R 10.1063/1.1448653 %T Depolarizing-field-mediated 180° switching in ferroelectric thin films with 90° domains %V 80 %X Switching of the out-of-plane and in-plane polarizations in polydomain epitaxial PbZr0.2Ti0.8O3 thin films is studied using three-dimensional piezoresponse force microscopy (PFM). It is found that, under an electric field induced between the PFM tip and the bottom electrode, the 180° switching occurs in both c and a domains. After the removal of this field, the spontaneous reversal of the out-of-plane and in-plane polarizations back to the initial orientations takes place, evolving via heterogeneous development of antiparallel 180° domains. The switching of in-plane polarization inside a domains and the preferential formation of reversed 180° domains at 90° domain walls are explained by the effects of the depolarizing fields caused by transient polarization charges appearing on these domain walls. © 2002 American Institute of Physics.