Multiferroicity and 180° magnetization switching in LaFeO₃via antisite defects

Materials exhibiting coexisting and coupled ferroelectric and magnetic orders are rare. Here we show, using density functional theory calculations, that introducing Fe_La antisite defects into pristine, non-ferroelectric, G-type antiferromagnetic (AFM) LaFeO₃ renders the material simultaneously ferroelectric and a defect-induced local ferrimagnetic phase. We assess the thermodynamic stability of Fe_La antisites and identify synthesis conditions under which they are likely to form. Nudged elastic band calculations indicate an accessible barrier for ferroelectric polarization switching. Supercell calculations containing two antisites show that the parallel, ferroelectric alignment of the defect dipoles is energetically favored over the antiparallel one. Interestingly, we observe an inverse magnetoelectric coupling in which the ferroelectric polarization controls the magnetic order. We further propose two defect-mediated magnetization-control mechanisms enabled by ferroelectric switching in LaFeO₃, both involving a 180° reversal: (i) switching the Fe_La antisite moments while the pristine G-type AFM order remains unchanged, and (ii) switching the pristine G-type AFM order while the Fe_La antisite moments are pinned by a static magnetic field. In both cases, exchange coupling between the antisite and pristine Fe sublattices enables magnetization switching, highlighting a defect-engineering route to electrically controlled magnetic states for data storage.