Effect of Cr³⁺ substitution on dc electrical resistivity and magnetic properties of Cu0.7Co0.3Fe2−xCrxO4 ferrite nanoparticles prepared by sol-gel auto combustion method

Using sol-gel auto combustion technique complex ferrite nanoparticles have been synthesized. Characterization with the help of X-ray diffraction (XRD) revealed that the synthesized materials Cu0.7Co0.3Fe2−xCrxO4 are of a single-phase cubic spinel structure with Fd-3 m space group. And also, the samples’ crystallite sizes calculated using XRD data yielded in the range of 19.28–32.92 nm. The lattice constants are calculated to be between 8.4099 Å and 8.4441 Å. The FTIR results revealed that the spinel structure remained undisturbed even after the Cr ions were doped. FESEM images display the materials constitute polygonal-shaped grains though at times irregularly shaped gains with slight agglomeration appear. EDS analysis confirmed that the sample contained the constituent elements. A decreasing pattern in DC resistivity with an increase in temperature was observed, ensuring the semiconducting character of the ferrites under investigation. VSM was utilized to characterize and estimate the magnetic features like magnetic saturation and coercivity of the samples.