Tunable structures of copper substituted cobalt nanoferrites with prospective electrical and magnetic applications

Spinel ferrites (SFs) show high potential in different aspects of modern technology. Particularly, copper ferrite represents a promising electrode material for supercapacitors and lithium based batteries. This paper is devoted to synthesizing and characterizing nanostructured copper substituted cobalt ferrites using an eco-friendly sol–gel method. Energy dispersive X-ray (EDX) and FT-IR analyses confirm the chemical composition and the successful formation of the cubic phase of CuFe 2 O 4 , respectively. XRD analyses based on Williamson–Hall (W–H) method indicate that the average crystallite size drops from 25.1 to 12.1 nm dependent on the Cu 2+ content in the samples. Further, scanning electron microscopy (SEM) reveals that the CoFe 2 O 4 (CFO) has a honeycomb structure, which gradually disappears with the soaring of Cu 2+ content in the samples and converts to a porous sponge-like shape structure. The investigated copper substituted CFO holds a high specific surface area equals to 102.5139 m 2 g −1 which satisfies the contaminant adsorption applications. The measured DC resistivity (ρ DC = 10 8 Ω m) is high enough to meet the requirements of transformer cores applications. Due to the difference in the magnetic moment between Cu 2+ and Co 2+ cations, the coercivity of the CFO significantly depends on the Cu 2+ content; it has declined by more than 50% for the system Co 0.25 Cu 0.75 Fe 2 O 4 in comparison to the pure CFO (H c = 1617.30 Gauss).