Structural, Dielectric and Electrical Properties of Sol-Gel Auto-Combustion Technic of CuFeCr0.5Ni0.5O4 Ferrite

Abstract

The CuFeCr0.5Ni0.5O4 (CFO) compound was synthesized using sol-gel reaction combustion technic. The structural analysis showed that the obtained composites have a polycrystalline nature and the cubic spinel structure ( space group). Microstructural analysis revealed the formation of spherical and elongated grains of our sample. The dielectric and electrical transport properties of CuFeCr0.5Ni0.5O4 were investigated in detail by Ac impedance spectroscopy in a wide range of temperature (200 K-400 K) and frequency (100Hz to100KHz). Our results show that the electrical modulus and impedance studies confirm the presence of a relaxation phenomenon with non-Debye type in the prepared sample. The activation energy Edc estimated from the slope of the linear fit plot is equal to 0.158 eV with frequency of 100Hz and 0.126 eV with frequency of 1MHz at temperature range 200K-400K. Close activation energies values were found from analyzes of relaxation time and dc-conductivity indicating that the relaxation and the conduction processes may be attributed to the presence of free carrier charges and impurities at the grain boundaries. The conduction process for samples is described by the NSPT model. The complex impedance analyses and modulus formalism confirm a grain and grain boundary mechanism contributing to the dielectric properties. The real and the imaginary parts of the impedance are well fitted to equivalent electrical circuit (Rg+ Rgb//CPEgb) was used for modeling the Nyquist data.

Microstructural properties, dielectric behaviour, conduction mechanism, impedance, and electrical modulus of La0.65Ca0.25Sr0.1MnO3 manganite

“…From this Table, the Rg is less than R gb . Such results can be related to the non-stoichiometric distribution of oxygen [46,47]. From Table 3, it is remarked that the R g and R gb decrease when the temperature is increased, indicating a semiconducting behaviour for our sample.…”