Magnetic and electronic properties for ultrathin BiFeO3 film under external electric field

First-principals calculations show that the magnetization reversal of BiFeO3 film can be observed in y component with reversal of electric field more than ±0.001 V/Å. The charge distribution and hybridization is determined by the surface atomic distortions in plane. Bi-6s stereochemically active lone pair is still able to contribute to the electronic localization and thus the electric polarization in the film