Ferroelectricity driven by the noncentrosymmetric magnetic ordering in multiferroic TbMn2O5:: A first- principles study

The ground state structural, electronic, and magnetic properties of multiferroic TbMn2O5 are investigated via first-principles calculations. We show that the ferroelectricity in TbMn2O5 is driven by the noncentrosymmetric magnetic ordering, without invoking the spin-orbit coupling and noncollinear spins. The intrinsic electric polarization in this compound is calculated to be 1187 nC cm(-2), an order of magnitude larger than previously thought.