Complex impedance and electric modulus studies of Al substituted Co_0.4Cu_0.2Zn_0.4Al_xFe_2-xO₄ ferrites prepared by auto combustion technique

ABSTRACT

Al substituted Co_0.4Cu_0.2Zn_0.4Al_xFe_2-xO₄ (x = 0.0, 0.1, 0.2, 0.3, 0.4 and 0.5) ferrites have been prepared using auto combustion route. X-ray diffraction studies revealed the formation of single phase spinel type cubical structure. The dielectric properties of the samples at room temperature have been studied over the frequency range of 20 Hz to 15 MHz. The dielectric constant and loss tangent is found to decrease with increasing Al content. Dielectric spectra analysis and modulus show the non-Debye type behavior in the material. Complex impedance spectra of the samples have been analyzed and explained using the Cole-Cole expression. The complex impedance data are indicative of the dominance of grain boundary resistance. AC conductivity has a trend to decrease with Al content and a shift of hopping frequency towards lower frequency is also observed.

KEYWORDS:

• Ferrites
• complex impedance
• complex electric modulus
• Cole-Cole plot

Acknowledgments

The authors are thankful to Dr. M.A. Gafur, Senior Scientific Officer, PP and PDC, BCSIR, Dhaka-1000, Bangladesh for extending experimental facilities.

Funding

The authors acknowledge the financial support of CUET.