Synthesis and investigation on the microstructural and electrical proprieties of Ni0.1Co0.5Cu0.4Fe2O4 ferrite prepared using sol-gel route

Abstract

In this work, the new polycrystalline spinel-type Ni0.1Co0.5Cu0.4Fe2O4 (NCCF) ferrite has been prepared via sol-gel method and analyzed using X-ray diffraction, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), respectively for structural, morphological, and elemental analysis. The refinement of X-ray pattern via the Rietveld technique asserts that the prepared sample exhibits the formation of a mono-phase cubic spinel structure with a Fd3¯m space group. The modified Scherrer and Williamson Hall (W–H) equations were used to evaluate the average crystallite size in the NCCF. Dielectric and complex impedance properties have been investigated in frequency range 102 ≤ f ​≤ ​106 ​Hz and in temperature range 300 ​≤ ​T ​≤ ​400 ​K using spectroscopy impedance. The ac conductivity was modeled using Jonscher's power law from 300 ​K to 340 ​K and Jonscher's augmented equation from 350 ​K to 400 ​K. Moreover, the temperature dependence of the dc conductivity revealed a semiconductor-metal transition occurring in our sample at TSM ​= ​370 ​K. The dielectric constant was exhaustively investigated vs. frequency and temperature and was obtained according to Maxwell-Wagner polarization. Col-Col plot of impedance data was used to evaluate the grain and grain boundary contributions in the NCCF sample.