RC circuit and conductivity properties of Mn0.6Co0.4Fe2O4 nanocomposite synthesized by hydrothermal method

• Dielectric constant decreases sharply with frequency and shows a DFT.
• The system shows a dielectric loss including two regions with DC conductivity part.
• Real and imaginary impedance parts represent an equivalent RC circuit design.
• AC conductivity is CBH type and activation energies for DC conductivity: 0.55 and 0.33 eV.
• Densities of localized states are in range of (7.7–3.2) × 1023 eV−3 cm−3.

Mn containing cobalt ferrite (CoFe2O4) nanocomposites were synthesized by polyethylene glycol (PEG) assisted hydrothermal method. Dielectric studies were carried out as a function of frequency and temperature using broadband dielectric measurement system. Dielectric properties were explained in terms of interfacial polarization and equivalent resistance–capacitor (RC) circuit. Frequency dependent dielectric loss factor has found to have two different behaviors which are explained by conductivity. DC conductivity obeys the Arrhenius law and exhibits two different behaviors corresponding to low and high temperature regions. It has two activation energies as 0.33 eV for low temperature region and 0.55 eV for high temperature region. Frequency dependent AC conductivity was analyzed by Jonscher’s universal power law which is varying as ws and the temperature dependent power parameter supported with the Correlated Barrier Hopping (CBH) model.