Rare earth magnetism and ferroelectricity in RMnO3

TL;DR

This paper investigates how magnetic rare earth elements influence the multiferroic properties of RMnO3 compounds, highlighting the role of symmetric exchange striction in enhancing ferroelectricity and proposing multi-magnetic ion strategies.

Contribution

It re-examines previous experimental data to identify the mechanism behind ferroelectric enhancement and suggests adding magnetic species as a novel approach to improve multiferroic properties.

Findings

Symmetric exchange striction may explain ferroelectric polarization enhancement.

Magnetic rare earths significantly affect multiferroic behavior.

Adding magnetic ions could be a new route to improve multiferroics.

Abstract

Magnetic rare earths R have been proven to have a significant effect on the multiferroic properties of the orthorhombic manganites RMnO3. A re-examination of previous results from synchrotron based x-ray scattering experiments suggests that symmetric exchange striction between neighboring R and Mn ions may account for the enhancement of the ferroelectric polarization in DyMnO3 as well as the magnetic-field induced ferroelectricity in GdMnO3. In general, adding a second magnetic species to a multiferroic material may be a route to enhance its ferroelectric properties.