Magneto-electric coupled CoFe₂O₄/MWCNTs nanocomposites for energy storage applications

Nanocomposites are in high demand because of their novel and emergent properties which makes them suitable for various technological applications such as electromagnetic interference shielding (EMI), sensing devices and electrode material design. A series of CoFe₂O₄/xMWCNTs nanocomposites with concentration (x = 0.0, 5.0, 10.0, 15.0, 20.0, 25.0 wt.% of MWCNTs) is reported. Cubic spinel ferrites were synthesized via the sol-gel method and then functionalized with MWCNTs. X-Ray diffraction (XRD) analysis confirmed the FCC structure of cobalt ferrite and the presence of MWCNTs, with a crystallite size of 16–20 nm. For x = 25%, a high dielectric constant ≈ 176 was observed. Relaxation phenomenon and polarization stages were explored in detail at high frequencies. Vibrating sample magnetometry (VSM) revealed the soft ferromagnetic behavior of nanocomposites. The observed magneto-electric coupling and high value of relative permittivity suggests that these nanocomposites could be used for multifunctional devices, magnetic sensors, high frequency microwave devices, and energy storage applications.