Nonfrustrated magnetoelectric with incommensurate magnetic order in magnetic field

Abstract

We discuss a model nonfrustrated magnetoelectric in which strong enough magnetoelectric coupling produces incommensurate magnetic order leading to ferroelectricity. Properties of the magnetoelectric in magnetic field directed perpendicular to wave vector describing the spin helix are considered in detail. Analysis of classical energy shows that in contrast to naive expectation the onset of ferroelectricity takes place at a field $H_{c1}$ that is lower than the saturation field $H_{c2}$. One has $H_{c1}=H_{c2}$ at strong enough magnetoelectric coupling. We show that at H=0 the ferroelectricity appears at $T=T_{FE}<T_N$. Qualitative discussion of phase diagram in $H-T$ plane is presented within mean field approach.

12 pages, 3 figures, accepted in JETP

References in corpus (3)

• Role of the Dzyaloshinskii-Moriya interaction in multiferroic perovskites
• Ferroelectric polarization flop in a frustrated magnet MnWO${}_4$ induced by magnetic fields
• Dynamical magneto-electric coupling in helical magnets

Cited by in corpus (1)

• Nonlocal Landau theory of the magnetic phase diagram of highly frustrated magnetoelectric CuFeO${}_2$