High-Field Study of Strong Magnetoelectric Coupling in Single-Domain Crystals of BiFeO3

Magnetic and dielectric properties of single-domain crystals of BiFeO3 were studied in pulsed magnetic fields up to 55 T. At low temperatures, metamagnetic transitions accompanied with sharp changes in electric polarization (P) were observed at around 18 T. The angular dependence of the transition field coincides with that of the transition from the cycloidal state to the canted antiferromagnetic spin state studied in the framework of the Landau-Ginzburg theory incorporated with the Lifshitz-like invariant. The parasitic P component caused by the cycloidal spin structure amounts to 210 +/- 30 mu C/m(2) in terms of the projected component on the pseudocubic principal axis, which can be controlled by applying magnetic fields at least up to 500 K. This result indicates that the microscopic magnetoelectric coupling in BiFeO3 is not weak: In fact, it is rather strong as compared to that in the canonical multiferroic material TbMnO3.