Unexpected type-II multiferroic phase in GdMnO3 under high magnetic fields

TL;DR

This study uncovers a novel high-field phase in GdMnO3 with large polarization, revealing complex magnetic and ferroelectric transitions driven by spin-lattice coupling, expanding understanding of multiferroic behavior.

Contribution

It reports the discovery of an unexpected type-II multiferroic phase in GdMnO3 under high magnetic fields, with detailed phase diagram and modeling insights.

Findings

Large magnetism-induced polarization up to 1500 μC/m2

Successive polar-nonpolar-polar-nonpolar phase transitions

Spin-lattice coupling as key to reentrant ferroelectric phase

Abstract

Perovskite manganites with small A-site ions, as the first and canonical branch of type-II multiferroics, are ideal systems to exhibit magnetism-induced ferroelectricity. Despite their established magnetoelectric phase diagrams under low magnetic fields, here an unidentified phase with a large magnetism-induced polarization (up to 1500 {\mu}C/m2) is revealed in GdMnO3 under high magnetic fields up to 60 T. Based on multiprobe experiments, a complete phase diagram is constructed with successive polar-nonpolar-polar-nonpolar transitions. Such a nonmonotonic evolution is well mimicked by model simulation, while the spin-lattice coupling is the key ingredient for the reentrant ferroelectric phase.