Spin correlated dielectric memory and rejuvenation in relaxor ferroelectric CuCrS2

TL;DR

This study reveals that CuCrS2 exhibits relaxor ferroelectric behavior with magnetoelectric coupling, memory effects, and rejuvenation phenomena linked to geometrical frustration and hybridization, indicating complex glassy dynamics above its Neel temperature.

Contribution

It uncovers the coexistence of relaxor ferroelectricity and magnetoelectric effects with memory and rejuvenation phenomena in CuCrS2, highlighting the role of geometrical frustration and hybridization.

Findings

Relaxor ferroelectric behavior observed above T_N

Memory effects and magnetic field induced rejuvenation detected

Magnetoelectric coupling persists above Neel temperature

Abstract

CuCrS2, a Heisenberg antiferromagnet with layered edge sharing triangular lattice, exhibits a spiral magnetic order. Dielectric (E) and polarization studies show magnetoelectric (ME) coupling at Neel temperature (T_N=38 K) where simultaneous dielectric and magnetic long range order occur. The compound shows a diffused ferroelectric (FE) transition and slow relaxation dynamics above T_N, indicative of relaxor FE behavior. Interestingly, memory effect and magnetic field induced rejuvenation are also observed in E, establishing cooperative glassy dynamics and ME coupling even above T_N. We discuss the role of geometrical frustration and metal ligand hybridization for these unusual properties.