Magnetism-Driven Ferroelectricity in Double Perovskite Y₂NiMnO₆

We report the discovery of multiferroic behavior in double perovskite Y₂NiMnO₆. X-ray diffraction shows that the material has a centrosymmetric crystal structure of space group P2₁/n with Ni²⁺/Mn⁴⁺ ordering. This result is further confirmed by aberration-corrected scanning transmission electron microscopy combined with atomic resolution electron energy loss spectroscopy. The appearance of ferroelectric polarization coincides with the magnetic phase transition (∼67 K), which indicates that the ferroelectricity is driven by magnetism, and this is further confirmed by its strong magnetoelectric (ME) effect. We proposed the origin of the ferroelectricity is associated with the combination of Ni²⁺/Mn⁴⁺ charge ordering and the ↑↑↓↓ spin ordering. When compared with other known magnetic multiferroics, Y₂NiMnO₆ displays several attractive multiferroic properties, including high polarization (∼145 μC/m²), a high multiferroic transition temperature (∼67 K), and strong ME coupling (∼21%). (Chemical Equation Presented).