Assessment of the optical and dielectric properties of f-MWCNTs/BaTiO3 nanocomposite ceramics

This research systematically evaluated the fabrication of the functionalized multi-walled carbon nanotubes (fMWCNTs)/barium titanate (BaTiO3) nanocomposite through the use of a simple two-step mixing route. Different concentrations of f-MWCNTs (0.25%, 0.5%, 1%, 2%, 4%, and 8% wt) were applied to the BaTiO3 matrix. The effects of different concentrations of f-MWCNTs on the structural and optical properties of BaTiO3 were investigated. Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) spectra were used for sample analysis. Using the FTIR spectra, the optical parameters of the refractive index and permittivity of the synthesized samples were calculated by Kramers-Kronig relations. The optical constants of f-MWCNTs/ BaTiO3 nanocomposites were strongly related to the concentrations of f-MWCNTs. This is because by increasing the concentrations of f-MWCNTs, both the real/imaginary parts of the refractive index and dielectric function were increased. Consequently, the transversal (TO) and longitudinal (LO) phonon frequencies were detected. The TO and LO frequencies shifted to the red frequencies by increasing the amount of f-MWCNTs in the BaTiO3 matrix.