Multiferroicity in a quasi-one-dimensional magnet MnSb2Se4

We report a comprehensive study of the structural, magnetic, and multiferroic properties of a quasi-one-dimensional magnet, MnSb2Se4, crystallizing in a centrosymmetric monoclinic structure. Magnetic and heat capacity measurements revealed that this compound undergoes a long-range antiferromagnetic ordering at TN = 22.5 K. A dielectric anomaly appeared at the TN in the absence of a magnetic field, and, an applied magnetic field of 9 T induced another dielectric anomaly just below the TN. Furthermore, the pyroelectric and DC-bias current measurements confirmed that these anomalies are associated with spontaneous electric polarization, whose magnitude becomes almost double under an applied field of 9 T. These results demonstrated that MnSb2Se4 is a type-II multiferroic material with strong magnetoelectric coupling. Moreover, a frequency-dependent dielectric anomaly observed at 5 K in the real component of the dielectric permittivity and loss data indicates relaxor behavior. © 2021