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

Abstract

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 CuFe2O4, 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 Cu2+ content in the samples. Further, scanning electron microscopy (SEM) reveals that the CoFe2O4 (CFO) has a honeycomb structure, which gradually disappears with the soaring of Cu2+ 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 m2 g−1 which satisfies the contaminant adsorption applications. The measured DC resistivity (ρDC = 108 Ω m) is high enough to meet the requirements of transformer cores applications. Due to the difference in the magnetic moment between Cu2+ and Co2+ cations, the coercivity of the CFO significantly depends on the Cu2+ content; it has declined by more than 50% for the system Co0.25Cu0.75Fe2O4 in comparison to the pure CFO (Hc = 1617.30 Gauss).