Weak ferromagnetism and magnetoelectric coupling in bismuth ferrite
arXiv:cond-mat/0407003 · doi:10.1103/PhysRevB.71.060401
Abstract
We analyze the coupling between the ferroelectric and magnetic order parameters in the magnetoelectric multiferroic BiFeO_3 using density functional theory within the local spin density approximation and the LSDA+U method. We show that weak ferromagnetism of the Dzyaloshinskii-Moriya type occurs in this material, and we analyze the coupling between the resulting magnetization and the structural distortions. We explore the possibility of electric-field-induced magnetization reversal and show that, although it is unlikely to be realized in BiFeO_3, it is not in general impossible. Finally we outline the conditions that must be fulfilled to achieve switching of the magnetization using an electric field.
4 pages, 2 figures, uses revtex4, to be published