We present a detailed study of the phase diagram surrounding the skyrmion lattice (SkL) phase of Cu2OSe2O3 using high-precision magnetic ac susceptibility measurements. An extensive investigation of transition dynamics around the SkL phase using the imaginary component of the susceptibility revealed that at the conical-to-SkL transition a broad dissipation region exists with a complex frequency dependence. The analysis of the observed behavior within the SkL phase indicates a distribution of relaxation times intrinsically related to SkL. At the SkL-to-paramagnet transition a narrow first-order peak is found that exhibits a strong frequency and magnetic field dependence. Surprisingly, very similar dependence has been discovered for the first-order transition below the SkL phase, i.e. where the system enters the helical and conical state(s), indicating similar processes across the order-disorder transition.
@article{arxiv.1412.0739,
title = {Dissipation processes in the insulating skyrmion compound Cu2OSeO3},
author = {I. Levatić and V. Šurija and H. Berger and I. Živković},
journal= {arXiv preprint arXiv:1412.0739},
year = {2015}
}