Abstract
Unusual emergence of magnetization induced by vacancy-strain interaction in non-magnetic ferroelectric PbTiO_3 is investigated using first-principle calculations. Atomic-scale ferromagnetism is observed at an oxygen vacancy under tensile strain, while under compressive strain it exhibits anti-ferromagnetism. These emerged magnetic properties are characterized by the split of defect electronic states via strain. We also reveal that the magnetic properties are changed by the polarization switching, that is, applied strain oxygen vacancies in PbTiO_3 exhibit atomic-scale multiferroicity and magnetoelectric effect.
