Domain wall roughness in epitaxial ferroelectric PbZr0.2Ti0.8O3 thin films

Abstract

The static configuration of ferroelectric domain walls was investigated using atomic force microscopy on epitaxial PbZr0.2Ti0.8O3 thin films. Measurements of domain wall roughness reveal a power-law growth of the correlation function of relative displacements B(L) L2ζ with ζ∼0.26 at short length scales L, followed by an apparent saturation at large L. In the same films, the dynamic exponent μ was found to be ∼0.6 from independent measurements of domain wall creep. These results give an effective domain wall dimensionality of d=2.5, in good agreement with theoretical calculations for a two-dimensional elastic interface in the presence of random-bond disorder and long-range dipolar interactions. © 2005 The American Physical Society.