Magnetic-field-induced spontaneous polarization reversal in multiferroicMn0.85Co0.15WO4

Abstract

The magnetic and ferroelectric properties of the multiferroic system Mn 1−x Co x WO 4 (x = 0.135, 0.15, and 0.17) are studied in magnetic fields H c oriented along the monoclinic c axis. Mn 0.85 Co 0.15 WO 4 , which is right at the phase boundary between two helical spin structures, exhibits a spontaneous sign change of the ferroelectric polarization when cooled in fields H c > 25 kOe. The origin of the ferroelectric polarization is studied and two magnetic exchange interactions contributing to the polarization are identified. In Mn 0.85 Co 0.15 WO 4 , domains of the characteristic helical spin structures, known for x < 0.15 and x > 0.15, coexist and form domain boundaries. The contributions of the different domains to the global polarization are determined. The polarization reversal in Mn 0.85 Co 0.15 WO 4 can be explained by a combination of various contributions to the polarization and a strong correlation between magnetic domains of different helical spin orders resulting in a smooth transition across the domain walls, which preserves the chirality of the spin spiral.

Magnetoelectric Coupling through the Spin Flop Transition inNi3TeO6

“…These findings advance the understanding of magnetoelectric coupling in materials in which magnetic 3d centers coexist with non-magnetic heavy chalcogenide cations. Spin and polarization flop transitions are fascinating, especially when controlled by external stimuli like magnetic and electric fields and accompanied by large material responses involving multiple degrees of freedom [1][2][3][4][5][6][7]. Multiferroics like MnWO 4 and TbMnO 3 are flagship examples and owe their remarkable properties, including field control of polarization and polarization reversal accompanied by spin-helix reorientation, to the heavy ions that bring strong spin-orbit coupling and magnetic anisotropy [8][9][10][11].…”

Pressure-induced decoupling of rare-earth moments and Mn spins in multiferroicGdMn2O5

“…Both experimental and theoretical researchers have been attracted in the recent years towards these materials because of the potential application in new generation devices as well as the complexity of the intrinsic microscopic interactions resulting in novel physical phenomena and properties. [1][2][3][4][5] The strong coupling between magnetic and ferroelectric order parameters and their mutual correlation in multiferroic compounds 3,6,7 challenges many open questions to researchers. In type II multiferroics, the inversion symmetry is broken due to unconventional frustrated magnetic orders and the polar electronic or nuclear distortions are induced through symmetric (Heisenberg) as well as antisymmetric (Dzyaloshinskii-Moriya -DM) exchange interactions.…”

Comprehensive inelastic neutron scattering study of the multiferroic Mn1−xCoxWO4

“…Among all magnetic or non-magnetic chemical substitutions, Co-doped MnWO 4 exhibits the most complex magnetic properties [29][30][31][32][33][34][35]. Only a few percent Co doping (x > 0.02) suppresses the AF1 structure completely and stabilizes the AF2 phase.…”