Room-temperature multiferroic properties in NiBi2O4

Magnetism and ferroelectricity at room temperature are observed in the NiBi2O4 ceramics. Both the time reversal and the inversion symmetry of the structure (space group F-43m) are broken. The saturation magnetization is 0.028 emu/g and the saturation polarization 2Ps~4.0 μ C/cm2. NiBi2O4 also shows other room-temperature multiferroic properties, e.g. the piezoelectric coefficient (d33), the polarized dielectric character, the magneto-dielectric response and the magnetoelectric effect.