Using multiscaling analysis, we compare the characteristic roughening of ferroelectric domain walls in PZT thin films with numerical simulations of weakly pinned one-dimensional interfaces. Although at length scales up to a length scale greater or equal to 5 microns the ferroelectric domain walls behave similarly to the numerical interfaces, showing a simple mono-affine scaling (with a well-defined roughness exponent), we demonstrate more complex scaling at higher length scales, making the walls globally multi-affine (varying roughness exponent at different observation length scales). The dominant contributions to this multi-affine scaling appear to be very localized variations in the disorder potential, possibly related to dislocation defects present in the substrate.
@article{arxiv.1205.0155,
title = {Multiscaling analysis of ferroelectric domain wall roughness},
author = {J. Guyonnet and E. Agoritsas and S. Bustingorry and T. Giamarchi and P. Paruch},
journal= {arXiv preprint arXiv:1205.0155},
year = {2012}
}