Elucidating the structure, ferroic properties and magnetoelectric coupling in Dy-doped BiFeO₃ nanostructures

Multifunctional Bi_1−xDy_xFeO₃ (x = 0.00, 0.20, 0.25 and 0.30) nanostructures were prepared successfully via the hydrothermal method. X-ray Diffraction analysis confirmed the rhombohedral (R₃C) structure of the main phase. The Dy-doping enhanced the magnetoelectric properties, linked to the decline in crystallite and grain size. The lowest band gap (2.05 eV) is observed in the Bi_0.7Dy_0.3FeO₃ system. The dielectric properties were improved by Dy-doping, with the highest dielectric constant of 25.94 observed in Bi_0.7Dy_0.3FeO₃. By Dy-doping, the ferromagnetism is induced in BiFeO_3, with saturation magnetization of 7.27 emu/g in Bi_0.7Dy_0.3FeO₃ nanostructure, while electric polarization and coercive field are reduced. The coexistence of ferroelectric and ferromagnetic behaviour established the multiferroic nature, with the highest coupling coefficient of 0.85 mV/cm/Oe in Bi_0.7Dy_0.3FeO₃. In conclusion, the Dy-doped BiFeO₃ nanostructures with improved dielectric constant, reduced band gap, strong ferromagnetism, and fascinating magnetoelectric coupling make them suitable candidates for optoelectronic and magnetoelectric devices.