X-ray scattering evidence for the structural nature of fatigue in epitaxial Pb(Zr, Ti)O3 films

We have probed the microscopic distribution of 180 degrees domains as a function of switching history in 40 nm epitaxial films of Pb(Zr0.30Ti0.70)O-3 by analyzing interference effects in the x-ray scattering profiles. These as-grown films exhibit voltage offsets (imprint) in the polarization hysteresis loops, coupled with a strongly preferred polarization direction in the virgin state. Our x-ray results are consistent with models attributing the loss of switchable polarization to the inhibition of the formation of oppositely polarized domains in a unipolar matrix. Using such model epitaxial films, we demonstrate that different microscopic ensembles of domains resulting from, for example, fatigue, may be resolved by this technique. (C) 2001 American Institute of Physics.