Ferroelectricity in the Magnetic E-Phase of Orthorhombic Perovskites

TL;DR

This paper demonstrates that the E-phase magnetic order in orthorhombic perovskite manganites and nickelates can produce ferroelectricity through a mechanism independent of spin-orbit coupling, with potential for significantly enhanced polarization.

Contribution

It reveals a new microscopic mechanism for ferroelectricity in E-phase orthorhombic perovskites, independent of spin-orbit coupling, and predicts a substantial increase in polarization.

Findings

Finite ferroelectric polarization is allowed by symmetry in the E phase.

The polarization mechanism is independent of spin-orbit coupling.

Predicted polarization can be up to 100 times larger than in spiral phases.

Abstract

We show that the symmetry of the spin zigzag chain E phase of the orthorhombic perovskite manganites and nickelates allows for the existence of a finite ferroelectric polarization. The proposed microscopic mechanism is independent of spin-orbit coupling. We predict that the polarization induced by the E-type magnetic order can potentially be enhanced by up to two orders of magnitude with respect to that in the spiral magnetic phases of TbMnO3 and similar multiferroic compounds.