Dielectric Behavior and AC Conductivity Studies on Cobalt Nanoferrites Synthesized Using Combustion Method

Cobalt nanoferrite particles were prepared by combustion method. The structures of the samples were studied with X-ray diffraction (XRD) using Cu-Kα radiation. The X-ray diffraction analysis revealed the nanocrystalline nature in the prepared ferrite samples. Dielectric and a. c. conductivity studies have been undertaken over a wide range of frequencies (100Hz-5MHz) at room temperature. The dielectric loss tangent (tanδ) was found to decrease with an increase in frequency. The dielectric constant (ε') and dielectric loss factor (ε") were found to decrease initially with an increase in frequency and reached a constant value at higher frequency, exhibiting a frequency-independent behavior at higher frequencies. A. c. conductivity of the cobalt nanoferrite was found to increase exponentially with the increase in the frequency. The electrical conduction mechanism in the cobalt nanoferrite is found to be in accordance with the electron hopping model.