Structural and Magnetic Properties of Cu2+ Substituted Co-Zn Ferrite Nanoparticles, Synthesized by Sol-Gel Combustion Method

In this work, the effect of Cu content on structural and magnetic properties of Cobalt-Zinc Ferrite nanoparticles synthesized by sol-gel combustion method have been investigated. All the samples exhibit cubic spinel structure and the lattice constant decreases linearly with increasing Cu-content. Average crystallite sizes calculated from Debye-Scherrer formula are in the range of 51-100 nm. The broadening of X-ray diffraction peaks decrease with increasing Cu content 'x' suggest that crystallite size increases with increasing 'x'. Cation distribution estimated form X-ray line intensity calculations show that Cu ions simultaneously occupy tetrahedral (A) and octahedral (B) sites with different ratio and Zn and Co ions occupies A and B sites respectively. With increasing Cu content a fraction of Co ions migrate to A site when x > 0.2. Grain sizes estimated from SEM are found to be increase with increasing Cu content. Particle size calculated using TEM for the undoped Co-Zn ferrites is about 55 nm. Saturation magnetization (Ms), Coercivity (Hc) and remanent magnetization (Mr) that varies significantly with Cu-Content. Saturation magnetization decreases from 90.7 emu/g (x = 0.0) to 51 emu/g (x = 0.4). The proposed cation distribution supports the variation in saturation magnetization and Coercivity with increasing Cu content.