An Effective Model of Magnetoelectricity in Multiferroics $RM{n}_2{O}_5$

Abstract

An effective model is developed to explain the phase diagram and the mechanism of magnetoelectric coupling in multiferroics, $RM{n}_2{O}_5$. We show that the nature of magnetoelectric coupling in $RM{n}_2{O}_5$ is a coupling between two Ising-type orders, namely, the ferroelectric order in the b axis, and the coupled magnetic order between two frustrated antiferromagnetic chains. The frustrated magnetic structure drives the system to a commensurate-incommensurate phase transition, which can be understood as a competition between a collinear or col-plane order stemming from the `order by disorder' mechanism and a chiral symmetry order. The low energy excitation is calculated and the effect of the external magnetic field is analyzed. Distinct features in the electromagnon spectrums in the incommensurate phase are predicted.

References in corpus (9)

• Spin current and magneto-electric effect in non-collinear magnets
• Ferroelectricity in spiral magnets
• Role of the Dzyaloshinskii-Moriya interaction in multiferroic perovskites
• Possible evidence for electromagnons in multiferroic manganites
• Spin structure and magnetic frustration in multiferroic RMn2O5 (R = Tb, Ho, Dy)
• Dynamical magneto-electric coupling in helical magnets
• Ferroelectricity induced by acentric spin-density waves in YMn${}_2$O${}_5$
• Electromagnons in multiferroic YMn2O5 and TbMn2O5
• Microscopic origin of Magnetic Ferroelectrics in Nonlinear Multiferroics

Cited by in corpus (5)

• Electromagnons in multiferroic RMn2O5 compounds and their microscopic origin
• Terahertz time-domain spectroscopy of electromagnons in multiferroic perovskite manganites
• The magnetoelectric coupling in the multiferroic compound LiCu2O2
• Spectral origin of the colossal magnetodielectric effect in multiferroic DyMn2O5
• Theory of magnetic field-induced metaelectric critical end point in BiMn${}_2$O${}_5$