The influence of cationic surfactant CTAB on optical, dielectric and magnetic properties of cobalt ferrite nanoparticles

Abstract In the present work, the influence of cationic surfactant CTAB (cetyltrimethylammonium bromide) on size, shape and coalescence behaviour of cobalt ferrite nanoparticles (CFNPs) synthesized via hydrothermal method is reported. Pure CFNPs show no additional peaks, whereas α-Fe2O3 phase is observed in CTAB added CFNPs upon annealing. FT-IR analysis confirms the formation of M − O vibrational bands (metal -oxygen) at tetrahedral A-site and octahedral B-site for both samples. SEM observations reveal less agglomeration and smaller particle size for surfactant added CFNPs. Raman spectral study confirms the formation of cubic spinel structure and Raman active modes of CTAB added CFNPs. UV–Vis spectra indicate a decrease in the energy band gap with annealing. The dielectric constant of surfactant added CFNPs decreases with increasing applied frequencies for both real and imaginary, but ac conductivity increases with increasing frequencies. Two sextet patterns of Fe3+ trivalent ions from tetrahedral and octahedral sites are observed in Mossbauer spectra. VSM study indicate the ferrimagnetic nature of CTAB added CFNPs. The electrochemical analysis reveals the pseudocapacitive nature of working electrode prepared by CTAB added CFNPs.