Structural, Dielectric, and Impedance Analysis of (Dy, Cu) Co-doped BiFeO₃

In the present work, the effects of (Dy, Cu) substitution on the dielectric and impedance behaviour of BiFeO₃ were investigated. The synthesized doped samples Bi_1−xDy_xFe_0.98Cu_0.02O₃ (0.01 ≤ x ≤ 0.05) were characterized by a combination of physicochemical techniques such as X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and dielectric and complex impedance spectroscopy. Rhombohedral perovskite structure was confirmed for all the samples. Crystallite size, microstrain, tolerance factor, bond length, and bond angle were calculated from the XRD data. FESEM demonstrates the microstructures as dense packed grains with well-defined grain boundaries. The grain size was found to decrease with increasing Dy concentration. Increased dielectric constant values with low dielectric loss were obtained with Dy substitution. Impedance analysis revealed the non-Debye relaxation to be prominent in the doped samples. Present results establish that the effect of rare earth doping on structural and electrical properties of perovskite BFO may have good prospects in scientific and industrial applications. (author)