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Domain Wall Roughness in Epitaxial Ferroelectric PbZr 0.2 Ti 0.8 O 3 Thin Films

2005; American Physical Society; Volume: 94; Issue: 19 Linguagem: Inglês

10.1103/physrevlett.94.197601

1092-0145

Patrycja Paruch, Thierry Giamarchi, J.‐M. Triscone,

Physics of Superconductivity and Magnetism

The static configuration of ferroelectric domain walls was investigated using atomic force microscopy on epitaxial ${\mathrm{PbZr}}_{0.2}{\mathrm{Ti}}_{0.8}{\mathrm{O}}_{3}$ thin films. Measurements of domain wall roughness reveal a power-law growth of the correlation function of relative displacements $B(L)\ensuremath{\propto}{L}^{2\ensuremath{\zeta}}$ with $\ensuremath{\zeta}\ensuremath{\sim}0.26$ at short length scales $L$, followed by an apparent saturation at large $L$. In the same films, the dynamic exponent $\ensuremath{\mu}$ was found to be $\ensuremath{\sim}0.6$ 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.