Realization of structural transformation for the enhancement of magnetic and magneto capacitance effect in BiFeO3\u2013CoFe2O4 ceramics for energy storage application

Muniyandi Muneeswaran,Nambi Venkatesan Giridharan,Juliano C Denardin,Miguel Angel Gracia-Pinilla,Ali Akbari-Fakhrabadi

doi:10.1038/s41598-021-81867-4

Muniyandi Muneeswaran, Nambi Venkatesan Giridharan + Show 3 more

Open Access

https://doi.org/10.1038/s41598-021-81867-4

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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/cm3 and the strong magneto capacitance was observed in 0.9BFO-0.1CFO, which belongs to the morphotropic phase boundary (MPB) region near to the BiFeO3-rich region. The magnetic response analysis has shown, the saturation magnetization (Ms) 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.

Highlights

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 been carried out
Further increasing of CFO concentration to x = 0.3 in (1 − x) BFO–xCFO resulted to almost disappearance of the Raman modes, which indicates a reduce in the stereochemical activity of the Bi ( 6s2) lone pair electron, which induces a sudden change in Bi–O covalent bonds possibly to the structural transformation from the rhombohedral to tetragonal crystal structure
The composition driven in structural transformation of the (1 − x) BFO–xCFO (CFO, x = 0.00, 0.05, 0.10 and 0.30) samples was investigated. (1 − x) BFO–xCFO (x = 0.10) shows a maximum energy storage density with strong magneto capacitance effect near to the morphotropic phase boundary (MPB) of tetragonal (P4mm) and the rhombohedral (R3c) phases

Summary

Introduction

A systematic study on the structural phase transformation in BFO-CFO ceramics has been made by varying the CFO concentration in order to investigate the first-time peculiarities of multiferroic behaviour has been done and their compositional driven microstructural, electrical, magnetic and energy storage density properties and enhanced magneto capacitance effect have been carried out.

Results

Conclusion