Neutron diffraction studies on crystal and magnetic structures of BiFeO$_{3}$ at high pressures*

As one of the most prominent examples of multiferroic materials, bismuth ferrite BiFeO$_{3}$ shows both electric polarization below $T_{C}$= 1100 K and long-range magnetic ordering below $T_{N}$= 640 K. The coexistence of both electric and magnetic order parameters at room temperature is particularly interesting for technological applications. However, the physical and structural properties of BiFeO$_{3}$ under pressure are still a matter of debate in the literature. Here we report neutron diffraction data on BiFeO$_{3}$ at 294 K up to 10 GPa. The evolution of both the crystal structure and magnetic structure of this material with pressure has been well determined. Our results shed insight on the long standing controversy surrounding the structural transformations at 3 GPa and 7-10 GPa reported by different laboratories.