We investigated the magnetic structure of an orthorhombic YMnO3 thin film by resonant soft x-ray and hard x-ray diffraction. We observed a temperature-dependent incommensurate magnetic reflection below 45 K and a commensurate lattice-distortion reflection below 35 K. These results demonstrate that the ground state is composed of coexisting E-type and cycloidal states. Their different ordering temperatures clarify the origin of the large polarization to be caused by the E-type antiferromagnetic states in the orthorhombic YMnO3 thin film.
@article{arxiv.1109.2366,
title = {Origin of the large polarization in multiferroic YMnO$_3$ thin films revealed by soft and hard x-ray diffraction},
author = {H. Wadati and J. Okamoto and M. Garganourakis and V. Scagnoli and U. Staub and Y. Yamasaki and H. Nakao and Y. Murakami and M. Mochizuki and M. Nakamura and M. Kawasaki and Y. Tokura},
journal= {arXiv preprint arXiv:1109.2366},
year = {2012}
}