Magnetoelectric Memory Effect of the Nonpolar Phase with Collinear Spin Structure in MultiferroicMnWO4

Abstract

The novel memory effect of a nonpolar paraelectric phase with a collinear spin structure has been observed in a magnetoelectric multiferroic material MnWO4. Since the ferroelectric polarization arises from a noncollinear spin structure, in a new class of magnetoelectric multiferroic materials with a spiral-spin structure, the information of ferroelectric domains should be lost in the collinear spin phase. However, in MnWO4, it has been found that the domain states in the ferroelectric phase are memorized even in the nonpolar phase with a collinear spin structure, when the phase transition is of the first-order type. Here we demonstrate a magnetoelectric memory effect that the ferroelectric single-domain state can be reproduced from the paraelectric phase by a magnetic field. We propose the nuclei growth model, in which the small ferroelectric embryos keep the polarization state in the nonpolar collinear spin phase.

Strong magnetoelastic coupling at the transition from harmonic to anharmonic order inNaFe(WO4)2with3d5Simon1, Ackermann2, Chapon3 et al. 2016Phys. Rev. B134220View full textAdd to dashboardCite

“…This is an essential difference to MnWO 4 where the incommensurate magnetic modulation is much further away from the commensurate value. Anharmonic components were also observed in the AF2 phase of MnWO 4 22 and there they are related with magnetoelectric memory effects observed for the electric-field control of multiferroic domains 23,24 .…”

Electronic structure and anomalous band-edge absorption feature in multiferroicMnWO4: An optical spectroscopic study

“…19,20 More recently, the magnetoelectric memory effect was identified in MnWO 4 by applying a magnetic field. 21 In this series of works, much attention was paid to the direct observation of the ferroelectric polarization and its behavior under a magnetic field.…”

Effect of Nonmagnetic Substituents Mg and Zn on the Phase Competition in the Multiferroic Antiferromagnet MnWO4

“…[4][5][6] Recent work has demonstrated that the ferroelectric and spin-spiral orders coexist and are intimately coupled in this material. [4][5][6][7][8][9][10][11] MnWO 4 undergoes three magnetic phase transitions in zero magnetic field below 14 K (Figure 1). 12 With decreasing temperature, MnWO 4 first transforms from a paramagnetic (PM) state to a collinear spin sinusoidal state (AF3) at T N ≈ 13.5 K, then to a tilted elliptical spiral spin state (AF2) at T 2 ≈ 12.3 K, and eventually to a up-up-down-down collinear spin structure (AF1) at T 1 ≈ 8.0 K. The magnetic structures of the AF3 and AF2 states are ICM to the lattice spacing with propagation vector k = (-0.214, 0.5, 0.457), while that of the AF1 state is commensurate (CM) with propagation vector k = (-0.25, 0.5, 0.5).…”