Magnetostriction-polarization coupling in multiferroic Mn 2 MnWO 6 .

Double corundum-related polar magnets are promising materials for multiferroic and magnetoelectric applications in spintronics. However, their design and synthesis is a challenge, and magnetoelectric coupling has only been observed in Ni ₃ TeO ₆ among the known double corundum compounds to date. Here we address the high-pressure synthesis of a new polar and antiferromagnetic corundum derivative Mn ₂ MnWO ₆ , which adopts the Ni ₃ TeO ₆ -type structure with low temperature first-order field-induced metamagnetic phase transitions (T _N  = 58 K) and high spontaneous polarization (~ 63.3 μC·cm ^-2 ). The magnetostriction-polarization coupling in Mn ₂ MnWO ₆ is evidenced by second harmonic generation effect, and corroborated by magnetic-field-dependent pyroresponse behavior, which together with the magnetic-field-dependent polarization and dielectric measurements, qualitatively indicate magnetoelectric coupling. Piezoresponse force microscopy imaging and spectroscopy studies on Mn ₂ MnWO ₆ show switchable polarization, which motivates further exploration on magnetoelectric effect in single crystal/thin film specimens.