High-field-induced multiferroic phases and polarization reversal in single crystals
Phys. Rev. B 113, 134441 – Published 27 April, 2026
DOI: https://doi.org/10.1103/kr9h-qcfr
Abstract
We report a systematic study of the magnetic and ferroelectric properties of single crystals under pulsed magnetic fields up to 60 T, revealing pronounced anisotropic magnetoelectric coupling and novel ferroelectric phenomena. For , in addition to a low-field spin-flop transition at T, two additional metamagnetic transitions occur at T and T, which correlate with a distinct new ferroelectric phase exhibiting anomalous polarization reversal. An intriguing characteristic of this reversal is the formation of a large “∞”-shaped hysteresis loop, arising from polarization sign reversal during the H-falling sweep relative to the H-rising sweep. This ferroelectric response is highly dependent on the field-sweep history, indicating complex magnetoelectric behaviors in the system. In the case of , successive metamagnetic transitions are observed at T, T, T, and T, with an additional transition at higher critical magnetic fields above 10 K. Each transition corresponds to distinct ferroelectric phases, which exhibit varying responses to the applied bias electric field (E). In particular, the high-field ferroelectric phase above demonstrates a robust memory effect, where both the direction and magnitude of electric polarization are retained across successive pulses of −E and +E. This suggests that the pinning of ferroelectric domain walls may prevent polarization reversal under opposing bias fields. Complementary magnetostriction measurements support the magnetization results and reveal spin-lattice coupling. Based on these comprehensive experimental findings, we construct the magnetic-field-temperature phase diagrams and investigate the underlying origin of magnetoelectric coupling in . Our results offer valuable insights into high-field-induced ferroelectric phases and unusual magnetoelectric effects in noncollinear multiferroic systems.
