Structural and electromagnetic properties of nano cobalt ferrite polymeric thin film

Synthesis of nano cobalt ferrite (NCF) was done by sol–gel auto combustion method. The effect of nano CoFe₂O₄ on structural and electromagnetic properties of polyvinyl alcohol (PVA) was evaluated on polymer based thin films. Polymer based nano CoFe₂O₄ was synthesised using solvent casting method having different concentration (0%, 2%, 4% and 6%) of nano CoFe₂O₄. Scanning electron microscopy (SEM) was employed for understanding the surface phenomenon like development of porosity and agglomeration caused by NCF in the PVA matrix. SEM analysis indicated the uniform dispersion of cobalt ferrite in 2% and 4%, it was also observed that further increase in concentration of 6% results to development of porosity on the surface of thin film. Fourier Transform Infrared (FTIR) were employed for understating the active functional groups. Vector Network Analyser (VNA) was employed to characterize the dielectric constant and scattering parameter (S₁₁, S₂₁) in X—band for understanding materialistic and electromagnetic behaviour of polymer based thin film. The value of electromagnetic dielectric decreases with the increase in concentration of Cobalt Ferrite which signifies the restriction in electron motion due to increase in doping concentration. Reflection coefficient (S₁₁) increases from − 32 to − 45 dB with increase in concentration (0–4%) of CoFe₂O₄ due to surface smoothness whereas it decreased at 6% doping due to development of porosity. Transmission coefficient (S₂₁) decreases with increases in concentration of CoFe₂O₄ due to formation of interconnected dipoles.