Dielectric behavior and a. c. conductivity studies on Co0.4Ni0.6Fe2O4 nanoparticles synthesized via combustion method

Cobalt-Nickel (Co
_0.4
Ni
_0.6
Fe
₂
O
₄
) ferrite nanoparticles were prepared by solution combustion method using cobalt nitrate & nickel nitrate as oxidizers and urea as a fuel. The structures of the sample 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. The dependence of dielectric properties such as dielectric constant (ε') and dielectric loss factor (ε"), dielectric loss tangent (tanδ) and the a. c. conductivity (σ) on the frequency has been undertaken over a wide range of frequencies (100Hz- 5MHz) at room temperature. 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. The dielectric loss tangent (tanδ) was found to decrease with an increase in the frequency. A. c. conductivity of the Co-Ni nanoferrite was found to increase with the increase in the frequency. The electrical conduction mechanism in the Co- Ni nanoferrite is found to be in accordance with the electron hopping model.