Intrinsic role of ↑↑↓↓-type magnetic structure on magnetoelectric coupling in Y_2NiMnO_6

摘要

Structure-property correlations are a major challenge in the investigation of magnetoelectric multiferroic materials. We have systematically investigated the intrinsic role of ↑↑↓↓-type order in magnetoelectric coupling in Y_2NiMnO_6. The calculated results reveal that the ferromagnetic (FM) order is the magnetic structure of the ground state and the total energy of ↑↑↓↓-type order is close to that of the FM order. The electric polarization is calculated to be 0.78 μC/cm~2 along the crystallographic b-axis for Y_(Ni) = U_(Mn) = 3 eV. In addition to the exchange-striction mechanism, a more noticeable contribution from redistribution of polarized charge is found in our study. Magnetic hysteresis loops show the ferromagnetism in Y_2NiMnO_6, which can be explained by magnetic field-induced spin flop transition from the E-type to FM order. Our DFT + U theoretical investigations also proposed a switching adiabatic path of magnetoelectric coupling, in which the 180° reverse of electric polarization is driven by rotation of spins.