Multiferroic memory effect far above the Néel temperature in single-crystal Gd0.5Dy0.5MnO3

Abstract

The memory effect of the polarized ferroelectric domain state in a nonpolar spin-density wave phase has been reported in few multiferroics and the origin of this effect has been attributed to the presence of polar nanodomains in the nonpolar magnetic state. From magnetoelectric and dielectric-relaxation studies, we show the presence of the memory effect beyond the antiferromagnetic ordering temperature (TNMn=39.5K) in a single crystal of Gd0.5Dy0.5MnO3. We suggest that the Debye-like relaxation behavior, which is a manifestation of localized charge carries or polar nanodomains in the crystal, is responsible for the memory effect. Intriguingly, a correlation of dielectric relaxation behavior to the magnetic interactions is found in a wide range of temperature including noncollinear spin-induced ferroelectric, the collinear nonpolar antiferromagnetic, as well as in the paramagnetic states.