Effect on structural, dc electrical resistivity, and magnetic properties by the substitution of Zn²⁺ on Co-Cu nano ferrite

Zn2+ substituted Co-Cu ferrite (Co0.5Cu0.5-xZnxFe2O4 where x = 0.0, 0.1, 0.2, 0.3, 0.4 and 0.5) nanoparticles were synthesized from sol-gel auto-combustion approach. A cubic structure was found with the study of XRD and FESEM. The linear growth of lattice constant from 8.384 to 8.409 angstrom was observed by Zn2+ substitution from 0 to 0.3. With the increase in Zn2+ ion content, the average crystallite size increases from 30 nm to 45 nm. FTIR shows their absorption peaks at 435-412 cm(-1), characteristic of the spinel crystal structure. The magnetic saturation of 86.35 emu/g with the Zn2+ substitution shows their superparamagnetic nature. The coercivity (Hc) values vary from 112 Oe to 415 Oe. These values make the investigated samples well suited for their use in recording media. The two probe's DC electrical resistivity kit within 370-580 K follow the Polaron hopping model resulting in their semiconducting nature. The activation energies of 0.30-0.50 eV are found with the help of the resistivity temperature plot.