Magnetic-instability-induced giant magnetoelectric coupling

Multifunctional materials such as magnetoelectrics can be used in novel device applications. Magnetism and ferroelectricity coexist in some materials, but the coupling between them is very small to use them in devices. Using density functional calculations we have shown that BiCoO3 (see figure) has large magneto-electric coupling owing to metamagnetism arising from a spin state transition of cobalt ion.