The effects of high magnetic fields applied perpendicular to the spontaneous ferroelectric polarization on single crystals of BiFeO3 were investigated through magnetization, magnetostriction, and neutron diffraction measurements. The magnetostriction measurements revealed lattice distortion of 2×10−5, during the reorientation process of the cycloidal spin order by applied magnetic fields. Furthermore, anomalous changes in magnetostriction and electric polarization at a larger field demonstrate an intermediate phase between cycloidal and canted antiferromagnetic states, where a large magnetoelectric effect was observed. Neutron diffraction measurements clarified that incommensurate spin modulation along [110] direction in the cycloidal phase becomes commensurate in the intermediate phase. Theoretical calculations based on the standard spin Hamiltonian of this material suggest an antiferromagnetic cone-type spin order in the intermediate phase.
@article{arxiv.1703.02306,
title = {Successive field-induced transitions in BiFeO$_{3}$ around room temperature},
author = {Shiro Kawachi and Atsushi Miyake and Toshimitsu Ito and Sachith E. Dissanayake and Masaaki Matsuda and William Ratcliff and Zhijun Xu and Yang Zhao and Shin Miyahara and Nobuo Furukawa and Masashi Tokunaga},
journal= {arXiv preprint arXiv:1703.02306},
year = {2017}
}