Impedance Spectroscopy Characterization of ZnCo₂O₄ Ceramics Obtained by the Sol-Gel Method

Abstract

In this article, structural, morphological and electrical properties of ZnCo₂O₄ ceramics sample were studied. ZnCo₂O₄ nanoparticles were synthesized using sol-gel method. Structural and morphological properties of the sample were analyzed using X-ray diffraction and scanning electron microscope. Conductance, capacitance and impedance spectroscopy characterization of ZnCo₂O₄ ceramics sample were analyzed in 3 kHz-1.5 MHz frequency range and 300-500 K temperature range. Nyquist diagrams of impedance and the equivalent circuit were studied for ZnCo₂O₄ ceramics in the temperature range of 300-500 K. Cole-Cole curves of the impedance data were found to show a semicircular arc in both low and high temperature areas, which is expressed by the equivalent electrical circuit R_s(R_gC_g)(R_gbQC_gb). Relaxation behavior was identified to be of non-Debye type. The Cole-Cole curve showed the negative temperature coefficient of resistance type behavior. Values of the activation energy corresponding to relaxation processes were found as 0.054 eV below 360 K and 0.561 eV above 360 K.

GRAPHICAL ABSTRACT

Keywords:

• ZnCo₂O₄
• Sol-gel method
• Impedance spectroscopy
• Frequency
• Temperature