Effect of yttrium on improvement of dielectric properties and magnetic switching behavior in BiFeO3

Yttrium (Y) modified nanocrystalline samples of BiFeO3 (BFO) were prepared by a metal ion ligand complex-based precursor-solution evaporation method. Partial substitution of Y (0-15%) at the Bi site results in structural change (rhombohedral to tetragonal) and single phase formation. With increasing Y concentration, enhancement in dielectric ordering, reduction in loss tangent and improvement in magnetic ordering in BFO were observed. Diffuse peaks in both permittivity and loss tangent were observed at 207 degrees C and 222 degrees C, respectively, for 15% substitution of Y. In all the Y substituted BFO samples, a switching behavior in low fields was observed in the field dependence of magnetization, even at room temperature, and this behavior was found to be improved with increasing Y concentration.