Fabrication of cobalt ferrite nanoparticles with a facile approach: Variations in structural, dielectric and morphological properties by influence of annealing temperature

Abstract

Spinel ferrites have a significant impact due to its physical and chemical properties. The sol-gel route has been employed in the present work, for achieving single phase nano-crystalline cobalt ferrites. All these samples were annealed with different temperatures from 600 ᵒC to 900 ᵒC in a muffle furnace. The FCC spinel structure of nanoparticles has been confirmed by powder x-ray diffraction (XRD) studies that demonstrate formation of crystalline size at various temperatures from 11–15 nm. The Raman spectroscopy revealed the characteristic absorption bands in 100 cm–1 to 700 cm-1 range where the graphs show five absorption bands and they confirmed the characteristic feature of spinel structure. With the help of Maxwell Wagner model, dielectric characterization has been carried out within a frequency range from 20 Hz to 20 MHz where dielectric parameters are found decreased with increasing the applied frequency. The alternating current conductivity phenomena increases with higher frequency ranges and show plane behavior in lower frequency ranges. The impedance mechanism, real and imaginary parts show decreasing trend on account of grain boundary activity. Interfacial polarization understood with the help of peaks obtained from the imaginary modulus pattern. These cobalt ferrite nanoparticles (CoFe2O4 NPs) are suitable to use in microwave devices, high frequency equipment, semiconductor devices and high storage media applications revealed by the dielectric studies.