Neutron diffraction study of the polarization reversal mechanism in [111]c-oriented Pb(Zn1/3Nb2/3)O3-xPbTiO3

The polarization reversal mechanism in [111](c)-oriented Pb(Zn1/3Nb2/3)O-3-xPbTiO(3) has been investigated by in-situ neutron diffraction. Stepwise static-field measurements of the (222)(c) rocking curves confirm a two-stage polarization reversal mechanism via a sequence of non-180 degrees domain reorientations. The time-resolved response has also been measured upon application of a bipolar square wave with a 30 s period to observe directly the relaxation times of diffracted neutron intensity during the reversal process. Upon application of a large antipolar field, the diffraction intensity increases quickly, before relaxing over a longer time period with an exponential decay constant, tau, of approximately 5.7 s. These large time constants correlate with a frequency dependence of the macroscopic strain-field response. (c) 2007 American Institute of Physics.