Realization of structural transformation for the enhancement of magnetic and magneto capacitance effect in BiFeO3–CoFe2O4 ceramics for energy storage application
M. Muneeswaran, Ali Akbari‐Fakhrabadi, M.A. Gracia-Pinilla, Juliano C. Denardin, N. V. Giridharan
Abstract
Abstract In this study, (1 − x) BFO-xCFO (CFO, x = 0.00, 0.05, 0.10 and 0.30) ceramics were synthesized by a solid-state reaction method; their compositions were driven by structural, microstructural, vibrational, electrical, magnetic properties; their enhanced magneto capacitance (MC) effect have also been carried out. Reitveld refinement studies of X-ray diffraction data shows composition-driven structural phase transformation from rhombohedral ( R3c ) to tetragonal ( P4mm ). Two phonon scattering Raman modes were observed for the higher wavenumber which supports the crystal structural transition in the BFO-CFO. Ferroelectric polarization shows that the polarization increased with increasing CFO concentration, which describes the changes of the polar symmetry of the crystal structure from rhombohedral ( R3c ) to tetragonal ( P4mm ). In Further, the maximum efficiency of energy density (η = 68.65%), reversible energy density of 0.138 J/cm 3 and the strong magneto capacitance was observed in 0.9BFO-0.1CFO, which belongs to the morphotropic phase boundary (MPB) region near to the BiFeO 3 -rich region. The magnetic response analysis has shown, the saturation magnetization (M s ) values of 83 emu/gm and 139 emu/gm for pure CFO and 0.7BFO-0.3CFO composite, respectively, and their magnetic behaviours were also confirmed with Arrott–Belov–Kouvel (ABK) plot.