Improved dielectric and magnetic properties of Co doped Bi0.80Ba0.10Nd0.10Fe1-xCoxO3 (x = 0.00, 0.01, 0.03, 0.05 & 0.07) multiferroic

Polycrystalline ceramic Bi_0.80Ba_0.10Nd_0.10Fe_1-xCo_xO₃synthesized via conventional solid state reaction method and their structural properties were investigated by Rietveld analysis of X-ray diffraction data. From the Rietveld refinement, it is confirmed that for x = 0.00, 0.01samples exhibit rhombohedral symmetry with R3c space group and for x = 0.03,0.05 and 0.07 structural phase modification takes place: samples exhibit mixed phase i.e. rhombohedral(R3c) and triclinic (P1) phase . Raman active phonon modes are consistent with changes in Bi-O and Fe-O bond lengths. Field emission scanning electron microscopy was used to study the microstructure and grain size of all the prepared samples. The elemental analysis of all the prepared samples was measured by using energy dispersive X-ray spectroscopy. Dielectric constant and tanδ shows dispersion behaviour at low frequencies and become nearly constant at higher frequencies for all the prepared samples which can be explained with the help of M−W model. Impedance spectroscopy reveals the contribution of both grain and grain boundaries in resistivity. A remarkable enhancement in magnetization was observed with Co doping. The maximum remnant magnetization M_r = 0.3868 emu/g and corresponding value of coercive field H_c = 0.6968 kOe was observed for x = 0.05 and slightly reduces for x = 0.07.