Magnetism and electronic properties of BiFeO3 under lower pressure

Ab initio calculations show an antiferromagnetic–ferromagnetic phase transition around 9–10 GPa and a magnetic anomaly at 12 GPa in BiFeO3. The magnetic phase transition also involves a structural and insulator–metal transition. The G-type AFM configuration under pressure leads to an increase of the y component and a decrease of the z   component of the magnetization, which is caused by the splitting of the dz2dz2 orbital from doubly degenerate eg states. Our results agree with the recent experimental results.