Structural, dielectric and magnetic properties of multi-walled carbon nanotubes decorated BiFeO3 nanocomposites for technological applications

In this study, an inexpensive technique known as the sol-gel auto-combustion method was employed for the synthesis of BiFeO₃ (BFO) nanoparticles. The BFO/MWCNTs nanocomposites with varying weight percentages of multi-walled carbon nanotubes (MWCNTs), specifically with x = 0, 5, 10, 15, and 20 wt%, were prepared using the ultra-sonication method. Toluene was employed as a functionalization agent to enhance the dispersion. Various characterization techniques, including X-ray diffraction (XRD), Transmission electron microscopy (TEM) and Raman spectroscopy, as well as dielectric and magnetic property measurements were conducted to comprehensively analyze the prepared nanocomposites. XRD analysis confirmed the crystalline structure of the nanocomposites. Scherrer's formula calculated the crystallite size based on the major plane peak in XRD patterns, which revealed a range of 45 nm–50 nm. TEM micrographs showed the morphology, dispersion and interaction of nanoparticles with MWCNTs. The Raman spectroscopy was utilized to reveal the phonon modes of the nanocomposites. The dielectric response was investigated in a wide range of frequencies ranging from 1 MHz to 3 GHz and observed a significant change with the addition of MWCNTs. Vibrating sample magnetometery (VSM) analysis was conducted under magnetic fields ranging from −20 to 20 KOe. The magnetic constraints such as saturation magnetization (M_s), coercivity (H_c), remanent magnetization (M_r), squareness (M_r/M_s) and anisotropic constant (K) have decreased with the increasing content of the MWCNTs. The high dielectric and low magnetic properties make these nanocomposites suitable for energy and data storage applications.