Distribution of antiferromagnetic rare-earth domains in multiferroic Dy$_{0.7}$Tb$_{0.3}$FeO$_3$

TL;DR

This study uncovers the domain pattern of antiferromagnetic rare-earth order in Dy0.7Tb0.3FeO3, revealing how it influences ferroelectric domain formation and contributes to understanding multiferroic interactions.

Contribution

The paper provides the first direct observation of rare-earth domain patterns in Dy0.7Tb0.3FeO3 using optical second harmonic generation, highlighting their role in multiferroic domain formation.

Findings

Dy/Tb domains form column-like structures perpendicular to electric polarization.

Rare-earth order influences ferroelectric domain wall charge and density.

Interplay between magnetic and electric orders defines the multiferroic domain landscape.

Abstract

In many multiferroics, rare-earth and transition-metal orders exist side by side. For analyzing their interaction and its consequences for the multiferroic state, the associated domain patterns and their spatial correlation can give valuable insight. Unfortunately, this is often hampered by the lack of access to the domains of the rare-earth order. Here, we uncover such a domain pattern for the antiferromagnetic and multiferroic Dy$_{0.7}$Tb$_{0.3}$FeO$_3$. Optical second harmonic generation reveals the formation of column-like Dy/Tb domains. Interestingly, the columns form perpendicular to the magnetically induced electric polarization. Hence, the antiferromagnetic rare-earth order forces the ferroelectric domains to form nominally charged head-to-head and tail-to-tail domain walls, thus playing a leading role in the domain formation within the multiferroic phase. In turn, to reduce energy cost, the ferroelectric order causes a reduced rare-earth domain-wall density along the direction of the electric polarization. This interplay highlights the multiferroic character of the Dy$_{0.7}$Tb$_{0.3}$FeO$_3$ domain pattern. We position Dy$_{0.7}$Tb$_{0.3}$FeO$_3$ within the broader landscape of rare-earth multiferroics and identify three distinct scenarios for the role of rare-earth order in these.