Crystal structure refinement and dielectric studies of Bi_0.80-xBa_0.20Dy_xFeO₃ (x = 0.05, 0.10) multiferroic

Ba and Dy co-doped at A-site BiFeO₃ ceramics have been successfully synthesized by a conventional solid state reaction technique. The analysis of crystal structure was done by X-ray diffraction (XRD) pattern. The Rietveld refined XRD pattern of prepared sample confirmed co-existence of Rhombohedral and Orthorhombic phases with R3c and Pnma space group, respectively. The low values of χ², R_p and R_wp obtained from Rietveld refinement shows good agreement between observed and calculated values. There is suppression of growth of secondary phases due to doping of small sized Dy³⁺ in place of Bi³⁺ ion. It has been found that the values of dielectric constant and dielectric loss increase with increase in temperature at different frequency. This is because of increase in number of charge carriers and their mobilities due to the thermal activation. Frequency dependence of dielectric constant and dielectric loss is understood using Maxwell Wagner model.