We present the results of detailed dielectric investigations of the relaxation dynamics in DyMnO3 multiferroic manganite. Strong low-frequency relaxation process near the paraelectric-ferroelectric phase transition is observed. The high frequency mode is directly to the relaxational motion of multiferroic domain walls. We provide an experimental evidence that this relaxation mode corresponds to a chirality switching of the spin cycloid in DyMnO3. We demonstrate that the relaxation dynamics in DyMnO3 is typical for an order-disorder phase transition and may be understood within a simple model with a double well potential. DyMnO3 follows an order-disorder transition scenario implicating that a short range cycloidal order of Mn-spins exists above TC. These results suggest the interpretation of the paraelectric sinusoidal phase in manganites as a dynamical equilibrium of magnetic cycloids with opposite chiralities.
@article{arxiv.1505.07949,
title = {Order-disorder type critical behaviour at the magnetoelectric phase transition in multiferroic DyMnO$_3$},
author = {M. Schiebl and A. Shuvaev and Anna Pimenov and G. E. Johnstone and V. Dziom and A. A. Mukhin and V. Yu. Ivanov and A. Pimenov},
journal= {arXiv preprint arXiv:1505.07949},
year = {2017}
}