Multiferroicity and 180$^\circ$ domain switching in LaFeO$_3$ via Antisite Defects

Abstract

Materials with coexisting and coupled ferroelectric and magnetic orders are rare. Here we show, using density functional theory calculations, that inducing Fe$_\mathrm{La}$ antisites into non-ferroelectric and antiferromagnetic LaFeO$_3$ renders the material at the same time ferroelectric and ferrimagnetic. Even more excitingly, we observe a direct coupling between the ferroelectric and ferrimagnetic polarization, the latter being switchable by the former. While on average the magnetic moments of antisites would cancel, we envision that preparing defective LaFeO$_3$ under simultaneous electric and magnetic fields will lead to a net magnetic moment due to magnetic domain reconfiguration. Moreover, ferroelectric switching under a static magnetic field can lead to 180$^\circ$ switching of the antiferromagnetic order in LaFeO$_3$.